Re: Complete 229 rebuild, and adventures in EGR.

[Malibufan]

Hey all.

I recently decided it was time to pull the heads on my 83 Malibu 3.8l 229 V6.
I drive this baby back and forth from Northern Wisconsin to Georgia about 6 to 12 times a year. Been reliable as heck. Always kept up on fluids, and changes. Been a great car. Got it with 96k original and I've put on about 30k in the year and a half I've had it. It was running rough for the guy that sold it to me so I checked all vacuum lines, rebuilt the carb, replaced the fuel pump, plugs, wires, and tightened all the fuel connections. Ran like a champ. Changed out steering box, all wheel bearings, calipers, rotors, upper and lower balljoints, inner and outer tie rod ends, center drag link, pitman arm, sway bar links, shocks all around, new door hinge pins, new door gasket seals, and a bunch of other little things I can't even think of. Basically, I want to have this car for a while. It's an 83 which is the year I was born, and I've always LOVED G-Body cars. My first two cars were 78 and 79 Monte's. Crashed one, and the other was stolen.
Sooo...
Out of nowhere I got a steady misfire in Cyl-6.
I've known for a long time that the heads needed rebuilding. Dollar bill trick at the tail pipe was more like the dissapearing dollar bill trick. It seemed to suck the bill against the exhaust pipe as much as it blew it away which was the worse it's ever been.
Figured bad exhaust valves and have been putting it off.
Car ran like a 15 year old 2 legged dog.
Changed plugs, wires, and dist. cap.
Miss was still there.
I figured "Yup, there goes that exhaust valve". Figured it burned all to #### so I didn't drive it and decided to take off the heads since I KNEW they needed to be rebuilt anyway. Didn't do a compression test #-o
Figured it HAD to be a burnt valve and since pulling the plug on the #6 cylinder made absolutely NO difference in the engine I figured I had it nailed.
Pulled the head and the valve showed minor burn. Only that valve leaked when I filled the runners with kerosene, and just BARELY. It wasn't a hole or a missing a good amount of metal like I was expecting. So I pull the other head thinking the other head must be REALLY bad. Other side all valves leaked kerosene. Intake, and exhaust. Intake valves leaked more than the exhaust so that spun me a bit.

Either way, I ordered 2 remanufactured heads for less than what they wanted to reman one of mine here locally.

While taking the intake manifold, and heads off I noticed more than a few loose bolts. No leaking of coolant between the gaskets so I was lucky to catch that. I thought maybe the loose intake manifold bolts could cause the engine to run crappy, but not so much on just 1 cylinder. Thought about it some more, and the vacuum port for the vacuum modulator runs right into the runner of the number 6 cylinder. Had some electric tape wrapped around it to hold it on.

Guessing that was probably the misfire problem, but I'm no mechanic. This is the first sbc I've ever taken apart. I've messed with all kinds of engines and am not afraid to jump into whatever and 9 times out of 10 I can get it fixed.

Also, the intake manifold EGR ports were CLOGGED. I don't mean a little. I mean SOLID PACKED for a good 2 inches. Ports on the heads were about as bad. I have had to run higher octane gas, or retard timing to avoid ping ever since I got the car. I figured it to be carbon buildup in the combustion chamber.

The EGR valve was disconnected when I got it, and I would REALLY like to get it operating again. From what I hear it cools the engine, and keeps detonation down which I would guess would increase MPG since I could stop running retard timing and maybe get some advance in there. The problem is, I've ordered a new EGR valve(the old one has a bad diaphragm) BUT I don't know how he heck to hook the thing up. I know how to put it in, but I don't believe it should go straight to a ported vacuum source. Most of the emissions stuff is gone. I'm not sure how to run the vacuum to it. I have a ported vacuum switch on the intake that I think is used for that, but I'm not sure what else I'm missing. Some kind of a solenoid I would think.

If anyone has any info on hooking up my EGR and getting it to function properly on a 229 3.8 I would give my pinky finger to hear it.

This is the only diagram I could find, and it's not that clear. Maybe I just don't understand it. Like I said, I'm no mechanic. I believe it shows the EGR coming from the Evap Control Solenoid. I don't have that. Wouldn't know where to start hooking it up unless I had a bit of help.

http://repairguide.autozone.com/zne...0c152/80/05/16/7c/medium/0900c1528005167c.gif

Thanks for checking this out. I'll get some pics up of the car, heads, engine block and all that tomorrow.

 

[Malibufan]

I've done some more reading, and I'm thinking that I may just need to run ported vacuum to the Thermal Vacuum Switch and then to the EGR.
I don't see why it wouldn't work. Keeping fingers crossed. I can't stand the thought of putting on new heads along with a thoroughly cleaned intake manifold just to have it all gunk up and have to do it all over again.

Also, I would love to be able to get the timing out of the retarded zone and run 87 without ping.
Just being able to advance the timing a bit (bring it to where it should be) should give me a couple more mpg I would think.

May end up rebuilding the bottom end as well while I'm at it. That way everything is done and with some luck I can get another 60-80k out of it before having to machine the block and rebuild again. If I had the money I'd go ahead and have it bored .010 over and have really fresh cylinders, but money is limiting.
Funny, the rebuild kit only cost 300 bucks, but the machining cost at least twice that around here.
If I was to get the crank ground, Align honed, cylinders bored, and all that I'm sure I'd be looking at some dough.

 

[Bonnewagon]

You are correct, the old school way was to run the EGR to ported vacuum, with a thermal vacuum switch in the line so it only worked when the engine was warmed up. By the way, the pinging is because with EGR diluting the air fuel mixture they added a lot of initial timing. Without the EGR it's too much timing and it pings. Turning the timing back to pre-EGR specs will eliminate it.

 

[Malibufan]

Ahaa. Thanks a million. I'll be swapping out the timing chain before putting this all back together. I'm guessing it's probably sloppy after 140k.
I don't have any timing tape on my balancer. I'll have to read around and figure out how to mark 0 on it. Should with No-1 at TDC on the comp stroke?
Like I said, I'm no mechanic, just a DIY, Reading sob.

 

[Bonnewagon]

Pretty easy to find 0º TDC. Just rotate the #1 piston to the top of it's travel, and mark the balancer in relation to something static like a bolt or bracket or even a dimple on the timing cover. Perhaps an old style bolt on or weld on timing tab can retrofitted. I see them pretty cheap on Epay, stock or chrome.

 

[jschevys1971]

Don't know if anyone has hit on this yet...(I taught Auto tech for 6 years)....But the concept of EGR is fairly simple:
It exists to reduce NoX Emissions by cooling the combustion chamber...
NoX is produced (Oxides of Nitrogen= global warming)....when the flame front reaches 1400 degrees...If memory serves me....
And exhaust gas is much cooler (and inert) than that......so a small amount is introduced into the combustion process during LEAN situations to reduce NoX.......
Lean = high combustion temps.....
Hope this helps.....

So...If the fuel mixture errs toward rich.....little to no Nox is produced...so no need for EGR

Also....spark knock/ detonation produces NoX....so ....avoid having the timing excessively high.....

 

[King_V]

This may help, if you want to route vacuum correctly and get the emissions devices operating properly:

http://www.autozone.com/autozone/re...epairGuideContent.jsp?pageId=0900c1528005163f

I see a regular and a high-altitude diagram for the 1983 229 V6. The non-high-altitude one looks... messy.

Also, basic idea - the EGR only works at cruise/part throttle - at WOT, there's little to no vacuum, so it doesn't affect anything adversely. Assuming, of course, nothing's clogged.

There is dilution during part throttle when the EGR is operating, which would technically reduce power. On the other hand, pumping losses are also reduced, as the engine's not fighting against as much vacuum. In addition, this cooler combustion chamber while the EGR is operating allows for more aggressive timing.

The net result is actually a small improvement to part-throttle fuel economy, as well as the NOx emissions reductions.

Theoretically it's a win-win. Of course, as you've discovered, things can get clogged up!

 

[Malibufan]

This may help, if you want to route vacuum correctly and get the emissions devices operating properly:

http://www.autozone.com/autozone/re...epairGuideContent.jsp?pageId=0900c1528005163f

I see a regular and a high-altitude diagram for the 1983 229 V6. The non-high-altitude one looks... messy.

Also, basic idea - the EGR only works at cruise/part throttle - at WOT, there's little to no vacuum, so it doesn't affect anything adversely. Assuming, of course, nothing's clogged.

There is dilution during part throttle when the EGR is operating, which would technically reduce power. On the other hand, pumping losses are also reduced, as the engine's not fighting against as much vacuum. In addition, this cooler combustion chamber while the EGR is operating allows for more aggressive timing.

The net result is actually a small improvement to part-throttle fuel economy, as well as the NOx emissions reductions.

Theoretically it's a win-win. Of course, as you've discovered, things can get clogged up!

I've got the high altitude (thank God) and I've been looking at that diagram, but can't find the EGR solenoid ANYWHERE.
Places say they have them, but can't get them because the manufacturer quit making them.
Called the manufacturer and sure sh*t, no go. Maybe a trip to the junk yard? 🙁

If anyone knows of a hook on one of these solenoids I'd be eternally greatful.
It's my first engine build and I'd hate to just put a block off plate on after cleaning the living hell out of all the EGR ports just to have them clog up again. Not sure if that would happen?

I pulled all the other smog stuff, but I'd like to have the EGR operating.
I think if I just ran it to ported vacuum it would be open much more than it should, am I correct?

 

[Bonnewagon]

You sure can, since that's how the factory did it before computers. Just be sure to use a vacuum gauge to verify a PORTED vacuum source, that shows 0" at idle, and rises slowly as rpm rises. If your particular ported source rises too fast, you can always put a restriction in the hose or use a vacuum delay valve to slow it down. The factory used a thermal vacuum switch to shut the EGR off when the engine was cold, for cold motor driveability. I don't use one and have never found it to be a problem, but then I allow the engine to warm up properly before I move. There are only two conditions where EGR will even be noticeable- if it stays on at idle you get a rough idle even stalling- and no EGR at all with the advanced timing which causes detonation.

 

[Malibufan]

Awesome. Appreciate all the advice, I really do.
The only issue I have now (other than the weather -30) is the torque specs for the con rod bolts.
I have the chilton manual but it's 1000 miles away right now.
I have the Haynes manual, but it doesn't give torque specs for the rod bolts. (Everything BUT the con rod bolts)
Right now they are at 50 Ft. lbs. which is about what is recommended for a 305 from what I've read but that could be WAY off.
I re-used the bolts if that matters.

Thanks Again.

MB