Engine Mismanagement System working perfectly? Check!

Status
Not open for further replies.

jiho

Royal Smart Person
Jul 26, 2013
1,001
508
113
Someone at GM tinkered with the controls on the unboosted 3.8L Buick V6 every year, '81 through '83. The '81 had a 3-solenoid pack on the passenger valve cover, one for charcoal canister purge, one for EFE, one for EGR. The EFE (Early Fuel Evaporation) solenoid operated a butterfly valve between the driver exhaust manifold and the crossover pipe, the butterfly being closed during warmup to divert exhaust through the intake manifold. For '82 the canister purge solenoid was removed, reverting the purge function to pre-computer control. Then for '83 things got more complicated. For the Federal version, the EFE solenoid and butterfly valve were removed in favor of a heater grid under the carburetor. The California version continued to use the 2-solenoid pack and butterfly valve from '82.

I give all this as background for the following. My '83 Malibu has the California version, meaning it's supposed to have the 2-solenoid pack and butterfly valve from '82. And indeed, it does for all the world appear to have that. Except it doesn't. Allow me to explain.

The EFE solenoid is supposed to be N.C. (normally closed), so unless the solenoid is energized the butterfly valve will be open for normal exhaust flow. But the one on mine is N.O, (normally open). So my ECM energizes the solenoid during warmup, like it should, expecting the solenoid to open and vacuum to close the butterfly valve. But the opposite actually happens. During warmup the solenoid is closed, so the butterfly valve is open and exhaust flows normally. During "normal" operation the solenoid is open, so the butterfly valve is closed and exhaust diverts through the intake manifold. The while you drive.

The EGR system is another matter. The EGR valve is the "positive backpressure" type, with an internal air bleed. So the EGR solenoid is not supposed to have an air bleed. But mine does. Beyond that I'm not sure my EGR solenoid is quite working right for what it is, even. With the solenoid "closed" and the air bleed unobstructed it holds no vacuum at all. Plugging the air bleed causes the vacuum to drop slowly like you would expect with a bleed.

So far as I know, my 2-solenoid pack looks just like factory. But clearly it is not. I have no idea who made it. In an attempt to make the car as "normal" as possible, I have swapped the two, EGR to EFE solenoid and vice versa, and disabled the EFE by reversing the check valve that GM conveniently had on it. Once it's warmed up the car drives better than it ever has. When cold it wants to stall at curb idle.

For now that's the best I can do, because these 2-solenoid packs are nowhere to be found. I managed to find one of the '83 Federal version EGR-only solenoids, but it has an air bleed and oddball wiring and of course no provision for EFE.

If I'm still stuck with this motor at smogcheck next year, I'm not sure what to expect. They definitely check the EGR system, but I find conflicting information on whether they are supposed to pay any attention to EFE or not.

And that's the tale so far, offered instead of a rant. I think I must be out of rants.
 

jiho

Royal Smart Person
Jul 26, 2013
1,001
508
113
I might add, if I do go to smogcheck with it rigged like this and they do flunk me on the visual, I could probably get a waiver from the Referee. But even then. I'd have to go to the Referee every year from then on, to keep the car registered this way with the waiver.

Meanwhile, I have about a year until my next smogcheck.
 
Last edited:

jiho

Royal Smart Person
Jul 26, 2013
1,001
508
113
I don't know how to respond to that. Tried a couple lame gags, nothing worked.
 
  • Haha
Reactions: 1 user

455'ed80Regal

Master Mechanic
Nov 3, 2010
467
211
43
Lincoln, MO
Makes me glad I live where I do.
 
  • Like
Reactions: 1 user

jiho

Royal Smart Person
Jul 26, 2013
1,001
508
113
That's what everybody says. I don't know if it helps to keep hearing that or what ....

Kinda makes me feel like I'm in traction in a hospital bed .... :mrgreen:
 
Last edited:
  • Haha
  • Like
Reactions: 1 users

xxBLOOD88SHOTxx

Greasemonkey
Jul 17, 2018
142
164
43
So are you wanting to keep that engine or not?

Does your emissions thingy people care what is under the hood of a 36 year old car? It isn't exempt at this point?
 

pontiacgp

blank
Mar 31, 2006
29,270
20,391
113
Kitchener, Ontario
It is just another tax that they don't want to call a tax....our cars are actually "greener" than any new car.....

"Making a new car creates as much carbon pollution as driving it, so it's often better to keep your old banger on the road than to upgrade to a greener model."
 
  • Winner
Reactions: 1 users
Status
Not open for further replies.

GBodyForum is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com. Amazon, the Amazon logo, AmazonSupply, and the AmazonSupply logo are trademarks of Amazon.com, Inc. or its affiliates.

Please support GBodyForum Sponsors

Classic Truck Consoles Dixie Restoration Depot UMI Performance

Contact [email protected] for info on becoming a sponsor