Carburator swap - need help!

[69hurstolds]

I posted below in another thread about this and I'm too lazy to type all this crap out again, but this may help you understand a little of what you're working with.

In a nut shell, you can apply a vacuum signal to the TOP small port on the canister vent valve. That's what closes carb venting to the canister off when the engine is running. If you do that and you hear a vacuum leak or sucking sound, the diaphragm is shot and you'll need a new canister vent valve. That's about the only thing you can check on these things. Other than making sure there's no cracks in it otherwise. Another "problem area" is the TVS switch on the intake manifold itself. The spring is always pushing on the top cap and during old age, the cap can pop off and the spring shoots out somewhere, and then it's time for another TVS switch.

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The vacuum switch is simply a thermal vacuum switch (TVS), a temperature activated port switch to open and allow vacuum from the carb at 170 deg F or above to draw vapors from the canister. It uses a Canister Control Valve (CCV), a ported vacuum valve just behind the TVS. The TVS has a plastic cap glued on top which is holding a spring down to continuously try and keep the valve closed when the thermal portion expands and pushes up on it. Sometimes that cap cracks and pops off, leaving the valve to leak vacuum like a screen door on a submarine.

When it's off, the CCV loses vacuum and opens to vent the carburetor bowl (3/8" hose on the front of the carb top) to the carbon canister through the CCV if you're TVS is still open. When the TVS cools off, the spring closes the TVS valve in effect cutting off venting the carb to the canister.

The charcoal canister absorbs those vapors from the tank and the carb, and they're supposed to sit there until the engine runs to temp again, getting sucked into the engine. There is an upper and lower membrane inside the charcoal canister that keeps the chunkies in place. If the upper breaks, the engine will suck up some granules. You'll find it in the hose to the TVS, from TVS to CCV, inside the CCV, and into the carb vacuum port. You can take all those hoses off and blow them out, but the canister and maybe the CCV is essentially done at this point. You CAN rebuild the canister with new activated charcoal bits from say the fish tank stuff, but it's a process.

You can try this, although I've never done it- take the TVS off, heat up the pellet end in a pan of water until it gets hot. Then blow air through one of the ports (top port preferably to go backwards), and then check to see that it seats when it cools off. If it does, no need to replace it. Although you can usually find them new for <20 bucks. The CCV diaphragm gets old and cracks eventually then leaks. So I'd just replace that if you're going to be fixing it.

A new TVS is GM p/n 22536551, or ACDelco part number 212-122, or Standard Motor Products PVS-42

A new CCV p/n is GM/ACDelco 17085929, or Standard Motor Products CP108

In the picture above from an 87 442 307 VIN9, you get this-
The Blue dashed hose is coming from the charcoal canister to the TVS.
The Red dashed hose is going to the CCV (has 16733 stamped on top of it, #4), it also comes out of the bowl vent on top front of the carb (#7)and comes into the large port on the side of the CCV.
The Green dashed hose is coming from the CCV to the baseplate of the carb (#6). This is where the venting goes for the charcoal canister when the engine is running and TVS is open.
The Tan dashed line (#1) is coming from the air cleaner diverter valve "Y" to provide full time vacuum on the CCV to close the carb vent when the engine runs.
The Orange dashed line is your PCV line to the carb.

Hope that sheds a bit of light for you.

 

[GermanDude]

thank you for your answer.
That helps me a lot.

So i think the cannister purge valve is correct connected and its w orking.
When I understand right, there musst be a vacuum @tvs when th engine is cold?
I have nothing whith a vacuum gun...!?!

 

[69hurstolds]

No. No vacuum at TVS when cold. Well, technically there could be vacuum up to the TVS if the engine is running as port #6 in the drawing has vacuum on it, it would be felt at the TVS, but it will be closed to the canister until the TVS warms up. In fact, it blocks off the canister path through the TVS when cold. When the engine is running and warmed up to operating temperature, the TVS should be open allowing the canister to pull through port #6 on the drawing for the CCV, and into the engine at the base of the carb. The fuel bowl is cut off when the engine is running because vacuum is applied to port #1 in the drawing to close the bowl vent. When the engine is shut off, the TVS will remain open for a while until the coolant cools down and closes the TVS. The vacuum is lost since the engine isn't running, the spring inside the CCV opens the reverse seated valve and allows the bowl to vent vapors through the TVS back to the canister.

The port you want to check is the small port that is in the center of the top of the plastic CCV valve (port #1 on the drawing, or the tan colored line that goes to the vacuum Tee in the picture). This is what closes the valve inside the CCV. If you have a hand-held vacuum pump (Mighty-Vac, etc.) with a gage on it, you could give it a couple of pumps and see if vacuum holds. If it does, it's still good. If it's old or original to the car, I'd see about trying to replace it since you're already in that deep already. They're a pain to get in and out of there as it is.

 

[GermanDude]

Hey guys,
now i checked the things that you told me and some other stuff. I think to remove ecm and stuff is the best way to get the car running.

Can somebody tell me something about the lockup kit?
It locks only the 4th gear? Is it only to save fuel? Im not driving very fast with the car.
Is there a risk of damaging the gearbox without lockup kit?

Thank you

 

[markweinberger]

GM in the 1980's was an experimental time for computer controlled cars...primarily the Carb., Distributor, and overdrive transmission...I also have a 1987 Olds 442....I had so much trouble with the crappy computer controlled Carb and 200R4 piece of crap transmission (which my 455 tore apart!)... I disconnected all ECM controls, tucked it away, and built a 1973 455 Q-Jet, installed a TH-400 transmission, and an Olds 455 Block bored .30 over...Installed a 3.08 Posi and she runs like a Muscle Car should...a true Olds Rocket!

 

[Clone TIE Pilot]

Hey guys,
now i checked the things that you told me and some other stuff. I think to remove ecm and stuff is the best way to get the car running.

Can somebody tell me something about the lockup kit?
It locks only the 4th gear? Is it only to save fuel? Im not driving very fast with the car.
Is there a risk of damaging the gearbox without lockup kit?

Thank you

Removing the ECM is not the best way to go. You have to understand how it works to even remove it. Is it throwing any trouble codes? If you have a analog dwell meter you could easily diagnosis the system, you would need such a meter to set up a non computer engine anyway.

Quick rundown, the computer controls the air fuel mixture for the primary side of the carb during idle and part throttle, ignition timing advance, EGR flow, transmission overdrive lockup, smog pump diverter valves, and the A/C kicker for Olds. Its so simple thst even a German can fix it.

Are you sure it is running rich? Its very easy for people to confuse rich and lean exhausts, lean mix smells much worse than rich. The computer will not work right on a engine that has underlying issues such as poor compression or vacuum leaks. CCC really hates vacuum leaks.

 

[olds307 and 403]

The lock up basically prevents torque converter slippage in high gear. If you don't drive on the highway, it isn't really necessary. It is a fairly easy install. You can do an auxiliary cooler as well, if you are worried about the excess heat generated. FYI the 2004R is not a POS, just not strong factory, especially the regular ones, your 87 442 has one of the best from the factory. If built by the right people with the right strength upgrades. The 2004R has gone 9's in the quarter mile in GN's. Dr Dan Mascal has one behind a low 11 second in his 84 H/O with a very built 500+ hp Olds 403, he builds them himself. The 2004R has much better gear ratios than a TH350/400, along with the .68 OD and lock up drop highway rpm by about 1000 rpm. As said the A/C wiring along with grounding the speed sensor black wire are necessary to retain the cruise control as well. Don't throw that factory carb away, it has value to the right people. Are you getting a check engine light? It is tough to diagnose across the ocean, many over here can't fix these CCC cars, let alone there. If you do get an aftermarket carb AND distributor, also necessary, get a wideband to tune the new carb. You already have an O2 port in the manifold to put the wide band's O2 sensor. That way whatever carb you purchase can be dialed in where it needs to be. Almost any carb out of the box will be rich for a 8 to 1 Olds 307 and most won't bolt to your spreadbore intake. The Street Demon 625 will bolt on and get a tuning kit for it, along with an Ebay Olds V8 vacuum advance HEI distributor and AEM wideband band will set you back about $1000 plus getting it over to Germany. Not a cheap option and will take trial and error to tune it right. Good luck.

 

[84 W40]

I would check to see if you have any codes first just like Clone TIE Pilot had said. There are many other things that can cause a rich smell with out showing a code, leaking well plugs that's under the carb. Low coolant if the ECM doesn't see a certain temperature it will think the engine is still cold and run rich. That is just a few possible problems, can you take picture of your carburetor just want to see if it has been rebuilt.