442 1985 442 Carburetor Stock Restoration-Refurbish

[69hurstolds]

Before going further, I was thinking about this earlier, but forgot to mention it when I was posting the pictures of mating the throttle body to the float bowl. Before doing that, it would be your last chance to permanently seal the float bowl bottom machining operation plugs for the jets and accel pump. These got a bad rap early on for being prone to leaking. I've heard them called "Leaky Q's" and "Quadraleaks", etc. I've had a couple of older early 70s 442 carbs that did leak from the secondary plugs. However, after doing a lot of research, I've found that the earlier carburetors had the plugs that were sealed in a different manner than the "newer" carbs. In fact, it seemed like Rochester was always trying to improve their carburetors and they made changes constantly and did so even in the midst of production runs. I'm not saying the CCC carbs never leak at the plugs, but I've personally never heard of anyone's CCC carb leaking from there. The old-timer way I learned was to clean the plug area at the leak and clean all the other plugs while you're in there, dab in some mixed up JB Weld on all the plugs, let it harden, and be on your way. And it did work on those old 442 carbs. But nowadays there are even better ways to fix that instead of the band-aid job.

As the CCC carbs were basically the last of the line, they got a better quality seal job for those plugs. My carb showed no signs of leakage upon disassembly, so I believe going through all the steps of drilling out the plugs and tapping them for screw plugs, then ensuring you didn't close off passages, etc., would have been overkill for this carburetor. Just another chance to destroy a float bowl if things went sideways. JMO. Had I seen evidence of leakage, I'd definitely have done that. But, I didn't, so I'm sending it as is. During the cleaning of the bowl, I filled the innards with acetone and nothing got wet underneath on inspection, so I'm confident it's still in good shape there. If things go wrong down the road, it's not difficult to fix.

Ok, moving on.

We still need to get the air horn ready to be installed, so we should probably install the choke plate and shaft. Again, shafts aren't normally removed when doing normal rebuilds, so you only need to do this if you fully disassembled the carburetor. Relatively easy procedure, but ensure you know which end goes to each side. Look at the ends of the shaft. One has a hole in it for a screw #30 to mount the choke flap lever #29. You must ensure the screw hole end winds up on the RH side, or choke housing side of the air horn. If not, and you install it backwards with loctite or staking screws on the flap, you'll be crying later. Know your ends. Follow the pictures and you'll be fine.

As usual with the screwed on plates, you'll need a little loctite or a means to support the screw from the backside in case you wish to stake the screw threads. This means the choke plate needs to be aligned in a manner to ensure it closes properly without interference. Again, I'm using loctite here so once you tighten down the screws where you want them, verify free operation of the choke, then carefully remove one screw, dab it with loctite, reinstall, and then do the other one. Again, verify proper operation. You'll only have a few minutes before the loctite sets up so ensure the parts move freely after installation. I want to maximize the working time as much as possible with the red loctite. You will too.

Note the choke flap strengthening feature in the middle of the flap. No, Rktpwrd didn't get hold of it on his metal roller, although I bet he could do it. The factory stamped a ridge into the flap to increase the rigidity of the flap. The flap will fit either way, but Rochester installed it with the part number up, and the raised part of the ridge up when the flap is closed. Will it make any difference? In this case, doubtful. You could argue that an arch (ridge up) is stronger than the ridge facing down as air flows down through the carb pushing on the flap, but c'mon, really? If there's a mystery reason I'm missing, I'll remove any doubt. I'm just going to do it the way RP did it. Raised ridge side up!

As far as the choke flap lever/screw, you DO NOT want any loctite on this screw. In the event you have to remove the air horn later on, you won't be able to if this thing is liquid welded. Or it would be extremely difficult by having to remove the choke assembly on the side of the carb. Yuk. Let's not even go there. NO LOCTITE on the choke flap lever screw!

Here's the choke flap installed per the CSM.

We'll set it aside for now. We'll come back later, finish off the air horn prep, remove the flap lever screw, and install it on the choke rod when its time to place the air horn on the float bowl.

Next up, the choke assembly!

 

[69hurstolds]

Here we go with the choke assembly. On the chart previously, it consists of parts #31 through #43 with the exception of #35 (secondary pull off rod). It's probably the last complex part that needs to be installed before putting the air horn on. Even so, we're just going to install the housing at this point as the coil and cover will go on later. There's a clearance check we have to do to make sure the choke is in the proper closed position when engaged. When we get to that, then we put the coil/cover on and then rivet it onto the housing, just like the factory did. Keep in mind this is an E4MC, and not an E4ME. The 4ME is the electric choke which does not require part #41 (choke housing shaft seal) or part #38 (choke housing to float bowl seal/air tube). In fact, if you convert your hot air choke to an electric choke, you should block off the air tube to the float bowl as you would no longer need air flow through the housing. A dab of RTV should do it. If you are keeping the hot air choke, then do not close off the hole (362 in the picture below)

Using the ACDelco carb kit, it comes with 4 round lip seals. Two larger ones which are thicker, and two smaller diameter, thinner ones. The larger ones are for the choke, the two smaller ones are for the air horn (accel pump and TPS extension rod). One of the seals goes into the side of the float bowl/main body (lip side out) and one goes into the hot air choke housing (lip side facing toward the inside the choke housing).
Choke seal on left, air horn seal on right. Lip side.

This is the back side of the choke shaft lip seal for comparison purposes.

Lip seal installed into choke housing.

Lip seal installed into float bowl.

Now's a good time to slide on the secondary lockout lever. It should move freely even after the choke housing is mated up to the float bowl.

Good time to put the seal/air tube into the float bowl as well.

The pieces/parts of the choke assembly.

Assemble the fast idle cam and intermediate lever into the back of the choke housing and make it look as such...

And we can secure the shaft in place by putting the choke spring lever in place. Torx T10 screw in this instance.

Make sure to line up the tang inside with the lever outside as such.

Now to wiggle all this mess back into place on the side of the float bowl. What makes this even tricker is that you need to also install the intermediate choke shaft lever #32 inside the little side compartment in the float bowl WHILE you're inserting the choke assembly into place. There's a special tool to hold that lever. It has 3 prongs and does a friction fit on the lever while you hold it in place, and slide the choke shaft into it. It doesn't matter which way it goes in, but obviously the big hole end goes over the intermediate choke shaft. It made it a bit cumbersome trying to take a picture of all this while trying to hold the choke housing and the lever using tweezers, so I'm just showing you the tweezers and lever shot. I used to have the 3 pronged tool, but somewhere along the line it must have eloped with that 10mm socket... 🙂 But tweezers do work.

You can see the lever in place in this next picture. It fits loose in there, and that's good. You'll need the room when wiggling the choke rod into the small hole end of it.

Now, with that part assembled, there's a single T25 torx screw that holds all this to the float bowl assembly. There's a guide "bubble" of sorts for the top leg of the housing, and the seal/air tube goes into the corresponding hole in the front leg. The back of the fast idle cam has a round piece made into it which sits just in front of the secondary lockout lever and when the choke closes, it allows the lockout lever to do its thing and lock the secondary butterflies. When the choke is open, the lever pushes back on the top of the lockout lever and releases the secondary butterflies.


Note the round peg near the bottom of the picture that rides on the front of the secondary lockout lever. When the choke is on, gravity swings the lever to the lockout position. Don't force things. With the choke "on" the lever should be free and you should be able to flick it around with your finger and should come back to rest on top of the end of the lockout pin residing on the secondary shaft. This would be normal. When the choke is "off" the lockout lever is forced off the lockout pin and your secondaries will be free to operate.

Note at the bottom of the picture the lockout lever is forced off the lockout pin on the secondaries. The choke is in the "off" position here.

That should do it for now. We'll come back to the choke later when we need to check it with the plug gage, then button it up with the coil/cover.

I reiterate- I am not an E-jet expert. But I have learned a thing or three over the years. If you have a question or need more details that can help you with your rebuild, just ask. There's 30 ways to skin a cat, and about 30 more ways to rebuild a carburetor.

 

[69hurstolds]

Things are looking pretty good in getting the top on this joker. First, we'll have to put the new TPS extension and the accelerator pump rod seals in. The lips on these seals face UP. Or toward the accelerator pump lever facing the outside of the carb. This was done as an emission thing to ensure fuel didn't evaporate and escape. If the holes for the seals weren't prepped when the old seals were taken out, now's the time to take care of that. You can take a sharp box knife and carefully carve off any staked material hanging over the edge of the seal bore. Then, after placing the seal, take the backing washer and press it down over the seal, and stake it in 3 places if possible. Doesn't take much, and don't go crazy, just enough to deform a little aluminum to smoosh (technical term) it over the edge of the bore to trap the backing washer. Do it for both. Good job.

Note: these seals are from the ACDelco kit. They are black. Sometimes aftermarket ones are green, or orange. Regardless, it seems the aftermarket ones are also a tad larger sometimes and don't hold the TPS extension rod very well and it will keep dropping out. Just throwing it out there. You could push the extension into the lever and place some masking tape on the outside of the air horn around it to help hold it in place as you put the air horn on. It's not tough, just sometimes you need 3 hands.

Here's a new TPS extension rod. These are easily lost, but not easily replaced. If you get the ACDelco TPS kit, you get a new one of these. All covered in green teflon.

Here's the TPS extension in place. It fits fairly snug in the seal, so I'm confident I'll be ok installing the air horn. Note just to the left of it is the adjustment lever for the TPS sensor plunger. That's the one with the tiny 2.5mm head bolt/screw that is a PITA to adjust if you don't have the right tool. When you turn the air horn over to install it, you want that screw backed all the way out and you may have to hold the lever up into place with something like a scraper blade or similar.

Grease up the Rich Stop Screw and ensure you grease the secondary wrap spring with Lithium grease and you're ready to install this bad boy. If you haven't done this when you disassembled the carb, now is the time to remove the rich stop screw, and use a small drift punch and hammer to tap out the aluminum plugs for the rich stop and the lean stop. Mine was already out, so I'm good to go.

This POS is a PITA. New NOS pump plunger with blue viton umbrella diaphragm for ethanol gas. And the return spring included. Not that I'll intentionally use ethanol, but if I need it and non-ethanol isn't available, it's one less thing to worry about dissolving. Installing this is fun because it's what wants to tear off the front corner of the air horn gasket while you're trying to do your thing.

Gasket in place, accelerator pump plunger in place, and you can see it doesn't want to stay there. Now you can drop in the paddle for the MC Solenoid. Dab a bit of lithium grease on the paddle button and stem before placing it in. Position the choke rod where you can install the air horn. Cross your fingers, I'm going in. (Note the air horn gasket in the back isn't laying down right because it doesn't quite fit nicely in the box. It's about 1/8" too long for the box. WTF GM?

No picture, but careful alignment of the air bleed and accelerator tubes, the choke rod, and TPS and accelerator pump rod alignment allowed for a smooth transition onto the float bowl. DO NOT FORCE ANYTHING. It should drop right in with the only resistance being the springs from the TPS and accelerator pump. You should be able to easily compress the springs to seat the air horn. Hold it down and install the 2 beveled T15 screws into the primaries just under the choke plate. Again, don't force. Just get them started and lightly seated. NO LOCTITE ON THESE SCREWS! So it's imperative you get them tightened so they don't fall out.

Then you can install the secondary baffle right behind the choke horn. Two T25 screws hold this in. Again, lightly seated. Install all the rest of the screws. 13 in all. All the screws outside the primaries are T25 heads.

Tech manual says torque the screws in this order, tightening all the screws evenly. Whatever that means to you. 🙂 Remember, this is aluminum you're working with. So don't go all Gronk on them. Snug them down, go take a break or do something else, but then come back later and snug them down again. The gasket compresses and will need retightening. You MAY have to do it again when the engine warms up again after installation.

And this's what tightening evenly looks like to me. Install the pump lever and hitch pin clip, and it's starting to look like a carburetor.

 

[69hurstolds]

It's time for the Idle Air Bleed Valve, aka IABV. This little joker helps meter air into the engine during idle, and it actually cycles with the MC Solenoid paddle to allow the correct amount of air at the right time dependent on the fuel travelling in the idle circuit. When it's in closed loop, this setting WILL affect duty cycle. So in order to set it right, you first need to know which one you have. There are two types of IABV's. One type is for a two-point adjustment, and will not have a letter stamped on top of the IABV. Three-points do, as well as having a separate rich stop. The 85 VIN 9 Oldsmobile has a three point adjustment carb, thus a letter should be found on the top of the IABV. In my case, it's a "Z". These are pretty tough little valves, so a quick check of spring action on the pintle should verify it's operating ok. The big problem with these guys is the 2 different sized O-rings. They tend to get hard and crack or crumble over time as they set almost square in their bore.

Below in the pic you see the valve with the letter, and the old O-rings with the new ones at the bottom. These are stressed as METRIC O-rings and these should be used. I'm not sure if they include these O-rings in aftermarket carb rebuild kits, but the ACDelco kits come with these O-rings. Smaller O-ring in bottom groove, larger O-ring in top groove. A dab of ATF for the O-rings (per the tech manual) for lubrication and you're good to go. You really shouldn't install these dry.

I have the tool for this. If you're rebuilding yours and don't have the tool, NORMALLY the rule of thumb is turn the IABV in until it's lightly seated, then turn 4.5 out. That should get you in the ballpark. I just backed mine out 4 turns, and I'll tune it in with the tool. Once you get it on the car and into closed loop, you can dial it in via the duty cycle or dwell. Look carefully and you can see the lean stop screw on the furthest front adjustment hole. The rich stop screw is in the hole just in front of the IABV, but you can't see the top of it because it's down in there. You WILL need a tool to get this rich stop setting right. Still want to leave the little plugs out until you get the carb dialed in on the car.

This is where I put the tool (seen in previous pics) in one of the vents and get it ready to press down and you want it to JUST TOUCH the top of the IABV.

Here it is where I'm going to leave it. The paddle is on the lean stop, and the tool is resting just on top of the IABV. Bench setting for the IABV complete here.

Now to check that you have 4/32" of full paddle travel from lean stop to rich stop. Since the lean stop was set by the 1.304" gage, you don't need to jack with that here. Not saying you won't ever need to adjust it once on the car, but likely you won't. The reading here with the measuring stick just sitting on top of the MC Solenoid paddle is 6/32". The paddle is resting on the Rich stop at this point.

Now, gently press down on the measuring tool until it stops. This presses the MC Solenoid paddle (as well as the primary metering rods) down to the Lean Stop. Reading the tool (my pic was a tad off on the angle, but you want to ensure you get this accurate) it reads 10/32". Thus, 10/32" minus the at rest position of 6/32", you get 4/32" total travel (1/8"). BOOM! You're in. Just what the tech info calls for. Your full travel is at spec. See? This crap is simple! Am I right? If you don't get the 4/32" total travel, use the tool to adjust the Rich Stop to get to 4/32" total travel. That's the goal.

 

[69hurstolds]

Now to start setting up the choke coil and cover. You do not have to install it at this point, but I found I can still do the checks and adjustments I need to do. You can wait until you do all the choke and fast idle settings if you wish. Depends on how good you feel about your skills.

Here is a check done prior to putting on the choke cover. Manually close the choke all the way and check for a hole in the choke housing. If you have a set of plug gages, insert a 0.120" gage in the hole and ensure the choke closes completely. If not, you will have to take some pliers and bend the choke rod near the choke flap lever to ensure it travels to the fully closed position when the gage is in place. Take the gage out before doing any adjustments. I've read where a #31 drill bit fits the hole as well, so if you don't have a plug gage...

What's in the choke cover/coil kit? A choke spring and cover, obviously, a pack of rivets and load spreading retainer springs, and the gasket. The ACDelco carb rebuild kit also comes with a pack of rivets, so in case you lose a set... If you want to use sheet metal screws, you can substitute those for the rivets.

Here you can see the alignment notches in the gasket and the cover. Meaning the coil/cover fits only one way.

Those notches line up with the front leg notch where the rivet or screw would go.

Install the gasket lining up with the notch. Then, just take the coil and point the inside tang at 6 o'clock and rotate it counter clockwise until you feel the lever tang inside the choke hosing connect with the spring, and continue to rotate it counter clockwise until the notches line up.

Hot dogs and hot dog buns. In the rivet kit you have 3 rivets and 5 different load spreading retainer springs. There is one that has a little tongue on it (bottom), and for this carb, you don't need it. So pick three of the others and you can discard the rest.

Here you can see where the load spreading retainer "springs" need to be placed where they're angled toward the housing when the rivet is place in. Then when you have all 3 lined up where you want them, use your rivet tool and pop those jokers home times 3. Choke is installed.

That's it for now. Just need to reinstall the secondary rods/hanger and tighten up that T8 screw for the hanger and the carb will be complete, sans the external adjustments. We'll get to that.

 

[69hurstolds]

So now, we've got a fairly completed carburetor on our hands. Time to do a few finishing touches on the external adjustments/checks and we'll call it bench ready. Then once it's bolted on the engine it can be finished off with the dwell checks and operational settings to dial it in, but that's down the road. We're going to stop once it's bench set and call it done for now. I went ahead and did the checks on this carburetor because it went rather quick and I was getting tired of working for 5 minutes, stopping, then taking pictures of what I was doing, then working for another 5 minutes. Besides, while waiting for the carb to get back from the platers, I took pictures of the Frankencarb while doing the checks on that. They're set up exactly the same.

So, let's refresh and get back to the "chart" of things we'll need to check/set/adjust...recall we'll be using the specs for 17085554, or the second line.

Looking at the chart, we've already set the float at 14/32". The lean stop is set via the tool at 1.304" and the Rich Stop total paddle travel for the MC Solenoid is 4/32". I've already preset the idle mixture screws, the IABV has been set with the shepard's hook tool at 1.756", the secondary air flap wrap spring is set to 1/2 turn past seating, and the choke stat lever has been go/no go checked with the 0.120" plug gage.

We're left with choke link cam at 14 +/- 2.5 degrees, front vacuum break at 27 +/- 2.5 degrees, secondary vacuum break at 41 +/- 3.5 degrees, the secondary air valve link clearance set to 0.025", and the unloader at 35 degrees, +/- 4 degrees. Oh, and the secondary lockout when locked at 0.015" max clearance. And at LEAST 0.15" clearance when secondary lockout is unlocked.

First, let's get the carb set up. CSM says to wrap a rubber band around the choke intermediate shaft (the green teflon one) to ensure it is held in the full choke position. This is something that will be done pretty much for all of the settings involving the choke. Anyway. Here's what I did.

Here's setting up the choke angle gage to the ZERO position. You place it on the choke plate with it fully closed as it will stick since it has a magnet on it and the choke plate is steel, and you're doing all this on a fairly level surface. Then with the gage pointer at ZERO. You use the bubble screw to level out the bubble. You will need to do all the checks like this. If you do them all in the same place, you shouldn't have to re-zero the gage every time. But, it doesn't hurt if you do. I use the Kent Moore adjustable carburetor stand that came in the tool kit, but you can use any sort of stand for this. You could even fab something up if you wanted. Just make sure it's dependable. Sometimes you will have to open the throttle blades, and having the clearance under the carb makes it easier. Plus you need a bit of clearance for the linkage anyway.

So while we're here, might as well do the front vacuum break while we're here. Looking for 24.5 - 29.5 degrees. (27 +/- 2.5)
First, you want to hook up a vacuum source to pull at least an 18" vacuum. Which isn't much, really, for just one pod. You just want it to fully retract and stay there while you check the measurement. So starting out at zero and level on the angle gage, set the pointer to 27. The bubble will be way off. That's ok. Now you apply vacuum to the front vacuum break and when it fully retracts, see if the bubble comes back to level. If it does, you're done. If it doesn't, you need to adjust. To adjust this, with vacuum still applied, you would turn the adjusting screw that's on the front vacuum break to get the angle gage where you want it (See phillips screwdriver in the real life pic below). You have a 5 degree swing, so it's not super-critical. But shoot for the middle.

That's done. Now, what's next?
How about we do the secondary vacuum break since the CSM procedure is on the same page? This one is 41 +/- 3.5 degrees. (37.5 - 44.5 degrees) And it's a bit easier. Again, wrapped rubber band around the green upper lever of the intermediate choke shaft simulating full choke. Zeroed angle gage, and a vacuum source for operating the secondary vacuum break. Set the pointer to 41. Apply vacuum to the secondary vacuum break and see where it goes. To make this adjustment, you will need to bend the looped connecting rod either forward if you need to open it more, or rearward if you need it to close more. This is one of those adjust and check, adjust and check, etc., until you get it where you want it. Note the pointer at 41, the bubble is level, and you can see my needle nose at the bottom left in the picture grabbing hold of the link rod. That's what you would need to adjust if you need to. I had 37 degrees initially, so I had to bend it forward just a hair.

And now we can do the secondary air valve link rod clearance for the primary choke pulloff (top procedure on this page of the CSM). Recall it's clearance spec is 0.025"

Easy peasy. Stick in a 0.025" plug gage. Go-no go here. Bend the rod at the 90 degree bend to adjust the clearance if needed. I put a white plastic ruler for a better background to see the plug gage. Boom! This one's done.

Might as well do the second part of this procedure too, the Unloader adjustment. WTF is an unloader? It's in the event you get stupid and flood the carburetor, what do you do? You FLOOR IT and hold the throttle to the floor. Without unloading the choke, you'll just pull more fuel in when you start cranking which is NOT what you want to do. Thus, when you floor it, the little tang on the fast idle cam linkage pushes on a half moon like lever on the intermediate shaft overriding the choke and forcing it open to allow air to get sucked into the carb when you're trying to "clear" the flood condition. Anyway, it's 35 +/- 4 degree setting. (31- 39 degrees) Amazingly, I didn't have to do a thing. Open throttle and the setting was right at 35 degrees with the choke unloaded. Had I needed to do adjustments, I'd bend the little tang as needed to increase or decrease the opening. TBH, if it was anywhere in the range, I wasn't going to mess with it. 🙂

Had I needed to adjust it, here's where I would put the needle nose pliers on the fast idle cam adjuster tang. Don't fugg with the screw, just the tang and only if you have to.

Ok, that's all for tonight. I'll try to get this thing wrapped up tomorrow with the rest of the adjustments and checks.

 

[Kra5379]

Well, that surely didn’t take long. Upon disassembly I got the top off no issues, but then hit a major block. I knew the lean stop screw can be a PITA sometimes but this one took the cake. I shot a bit of PB Blaster in the vicinity of the the threads. Let it soak for a while, but no dice. When I went to turn it the screw was hard to turn. These super-fine threads are touchy and you can’t grunt them or you will pay. You also need to release the spring tension by pressing down on the solenoid so the threads don’t get gobbled up. I tried gently working the screw back and forth a bit but it suddenly broke right at the top few threads. FUUGGGGG! I suppose age and galvanic corrosion got it. Since there’s no way to get that piece of screw out, I’m pretty much done with this carb main body. Don’t know for sure yet. I know a machinist buddy that may can rig something up. We’ll see.

So it’s on reset. I have another period correct 5554 carb I’ll be getting after next. Setbacks are part of the fun. I may have another bowl somewhere as well. Got to see what I did with it. Or if I still got it.

I feel your pain!! I decided to live dangerously a couple years ago and make my E2ME the very first Carb I would ever attempt to rebuild….wasn’t aware that I’d have to redo it 4 times before I got it close to functioning properly🤦🏼 Which reminds me, it’s probably about time to go through it again, and see if I can do a better job in one try now

 

[Kra5379]

I normally just do stuff without regard to doing anything as a how-to because I never know what task or when I might get myself involved in. I never think about "hey, this might be something someone else hasn't done and may like to see it." So normally nothing is documented. This time around, I figure I'd try one out for size and attempt a how-to.

Preface this with the warning: DO NOT TRY THIS AT HOME. I am not an expert. If I explain something wrong here, it was not done with malice or ill-intent. I make mistakes and typos and all that. Prone to error. So if you follow this as a recipe, don't blame me for your burnt cookies at the end of the baking cycle. I'll do my best to educate and discuss, and for some it may be old hat, but for others, it just might make the difference between running and sitting. Who knows?

And for your next act….a video version!!! 🤣🤣

 

[69hurstolds]

Now, back to the plug gage for the secondary lockout. The CSM states 0.015" MAX clearance between the pin and the locking lever when engaged. This may be a good thing, but I've checked many of my carbs for this sort of thing and every single one of them were factory set to something more than that. And they seem to work just fine otherwise, so technically, I don't care. The only thing I care about is whether the lock clears the secondary butterfly shaft pin when the choke is "off" so the secondaries will open. I actually measured somewhere around 0.020".

But for the sake of showing you the 0.015" pin in real life, it's super simple. You want 0.15" MAX clearance when engaged, and 0.015" clearance MIN when unlocked. Go-no go testing here.

CSM procedure states if the clearance is too much, bend the pin on the secondary shaft to make that clearance happen. Guess what. That little booger is hardened steel. I've tried bending it, and it's a tough SOB. So, no. Sorry. Even the factory didn't do it, so the CSM ain't going to make me. If your clearance is too tight when unlocked, this COULD cause you problems so this one is a bit more critical IMO. So filing off the tip of the secondary shaft pin would probably be ok to do if you have to. Usually there's a hefty gap and you won't have to worry much about it.

Here's the procedure (and the spec chart) again for your enjoyment.

Here's one of my other carbs I grabbed and checked it showing you where to put the pin when engaged. It was a bit loose as well. You can see the plug gage going into the gap. Not much play there anyway.

While we're here, lemme show you the tool they like to show you in some of the diagrams to bend rods and tangs. It's J-9789-1, and comes in the carb tool kit I got with the plug gages and angle gage and carb stand. I don't like it because it just seems too bulky compared to the needle nose pliers. But it's out there if you wish to seek one out. Just a solid steel rod with a slot cut in the end of it.

One more mechanical adjustment/check to do and that's the choke link cam, or Fast Idle cam adjustment. This one is set at 14 +/- 2.5 degrees. (11.5 - 16.5) Not a hard one to do, and it's designed to maintain the choke blade open slightly to about 1/2 the primary choke pull off amount from the chart. Recall, the primary choke pull off is set at 27 degrees. By rights, you shouldn't have any issues here as when the engine is running your primary choke pull off should have that choke plate open past the 14 degrees. But this setting ensures you have the choke plate open slightly when you're on the second step of the fast idle cam. Your car may not run pretty if the primary choke pull off fails, but it still should run until the choke heats up.

This setting is for the 2nd step on the fast idle cam. Basically, if you close the choke all the way and blip the throttle to set the choke, you are on the high step of the cam. Push the choke intermediate shaft weight forward until you hear it "click" into the second step of the cam, and ensure it's butted up against the high step. If you're not getting contact, screw the fast idle screw in a turn or two to ensure you're getting it "seated."

The final fast idle speed adjustment is performed via the emissions decal procedure, which sets the fast idle cam on its LOWEST step, and set at 750 rpm in drive. Curb idle screw setting is 550 rpm in drive, and the Idle Speed Solenoid screw idle setting is 650 rpm in drive. Follow the emission decal for these settings and how to get there.

Best thing to do is get rid of the primary choke pull off if you've installed it already. Just remove it via the two T15 screws holding it on and remove the vacuum hose from the T fitting hanging out in front and take the link rod out with it and set it out of the way for now. You can install it once done. I've got the choke spring and cover installed already, so I don't need the rubber band. You can still use it if you like, but on the car you won't be keeping the rubber band on so with the spring trying to hold everything to close, it is coming up with the same readings on the angle gage, so that's why I went ahead and put the choke spring back in already.
Ah, yeah. 14 degrees and bubble centered. Started with about 10, so like before, if it was in range of 12 or better, I'd have left it. But since it needed a nudge, I went for 14.

And since it needed adjusting, take a look and see that this time you use pliers to adjust the tab. Bend forward if you need it to open more like I did, bend rearward if you need to close up the gap. Factory settings are all fugged up it appears. Quality wasn't job #1 at GM back in those days. Note the silver tang just behind the green intermediate choke shaft. THAT'S the adjustment point you use the pliers on. The front of that tang butts up against the contact point on the green intermediate shaft and will adjust the choke plate as necessary depending on which way you bend it. It doesn't take much, I can tell you. It's another one of those adjust, check, adjust, check, and you keep jacking with it until the bubble centers at 14 degrees.

After you get it where you want it, re-install the primary pull off, and put this procedure in the "done" column.

That pretty much does it for the mechanical installation of the parts and mechanical bench adjustments for this VIN 9 carb. Next section we'll move on to the electrical adjustment. That's right. ELECTRICAL. Don't worry. Use a good digital voltmeter with a 10K ohm resistance made for automotive work, and this will be simple.

Oh...wait a minute. There's ONE more mechanical" thing to do here before we call in the multimeter to "preset" the TPS.

I would be amiss to not install the sticker that was removed prior to replating. The "5554" part number sticker that goes on the back of the secondaries on the driver side.

Mechanicals are DONE!

 

[69hurstolds]

I did this on the Frankencarb, and took the pics, so this is more for procedure. You do not have to do this part if you don't want to take the time to do it. Theoretically, you just bolt it on and crank it up, then set it per specs when it goes into closed loop. But in case you see some problems on the bench, it's better to fix it now before it lands on the car. Just one less PITA thing. If you're pressed for time, just do it on the car.

What we're trying to accomplish here is to simply get in the ballpark for TPS setting on the bench so that you are "close" when you crank up the car. You still may get a code for high or low TPS voltage while doing it on the car. That's ok, you'll clear all codes anyway once you're done adjusting. This will simply speed up the TPS adjustment on the car. Plus, it's exactly what you'd be doing on the car anyway, so you can get a bit of practice in on it before you actually do it.

Recall you did NOT install the TPS cover plug (along with the Lean and Rich stop plugs) as you want to ensure adjustability during closed loop operation. You'll install the plugs later after you get the stops where you want them and the TPS fully adjusted.

Using a 5.0 volt DC power supply, I rigged up power to the TPS reference signal. I realize this will not be the exact voltage you'll see on the car, but it will still be pretty close. If I had one of those whamodyne adjustable power supplies, I could dial in exactly what I need, but you will STILL need to check it on the car anyway. I wouldn't use it enough to justify the expediture to get one. I already had the 5V DC power supply, so I'm using it.

Starting at the top, recall you have an A, B and C connection points as you go down the connector. A is the 5V DC in reference signal from the ECM. B is the variable signal return BACK to the ECM. And C is the common, or ground. Hook up the voltmeter to check the voltage going in and you can see it's a tad higher than 5V. It's very likely and not unusual that you may see slightly less than 5V on the car. Which is ok, the point is the ECM will see a differential voltage and calculate the throttle "position" from this. It is extremely important that you get the TPS position set as close as you can to 0.41V at 550 RPM in drive. It's not going to kill anything if you're at 0.40 or 0.42, but if you can get it set at 0.41, that's as good as you can get.

You can see the reference voltage here at 5.14V DC. A tad higher than what you'd see on the car's actual ECM reference voltage for the most part, but that's ok. We're just ballparking it here on the "bench".

And now you can adjust your curb idle screw to 550 simulated rpm (just a wild guess on the curb idle), and ensure the choke isn't engaged and you're off the fast idle steps. Adjust the TPS adjusting screw with a suitable tool as you can see in the picture to get your output reading at terminal B (middle terminal) to 0.41V DC and you're golden. It's pretty sensitive trying to get 1/100ths of a volt, so take your time and do it slow. Once adjusted, let it settle out. Crack the throttle open and return it and see if it returns to 0.41V. Don't worry about a couple hundredths of a volt, but you don't want it going all wild on you and throwing codes.

And with that, we are DONE DONE with this carburetor! Now it's ready to bolt on and do the operational setup on the car. A few tweaks and it should run like a new one again!
Good luck everyone. I hope this little rebuild thread can help you out.

EDIT: Just wanted to add that I edited post #15 to add the ohm check across the body and terminals for the MC Solenoid. I meant to show that, but forgot. So I went back and added it. Super simple check, but hard to do once you put the carb back together.