joeld Posted June 21, 2007 Report Share Posted June 21, 2007 Hello folks, new to this but happy to be here. Working on a 1995 Pont Grand Prix 3100 engine with 150k. Engine runs like new with no drive problems at all. But this cod 77 keeps coming back. I have test EGR by using a 9 volt battery to manually open all three sol. controlled pintles, and all open and close fine. I have also grounded each sol. one at a time with engine running while observing scan tool read-out on RPM, which did drop momentarily. Also the MAP readings did change as the should when each pintle is open. Next I installed another EGR valve from a donor car to experiment with. Condition of this valve is seems to be OK as I did all the above test on this valve as well. But after driving approx 20-30 mile I got my code 77 again. Allways the same code and only this code. Like I said the car runs fine, I have owned car for 2 years, befor that original owner was a family member. So I know the car very well. Any thoughts on why just this code 77. One last thing, I had the upper and lower intake off 5k miles ago so I know there is no carbon build up. Besides, all three pintles open into the same basic area for flow. Thanks for any help. Quote Link to comment Share on other sites More sharing options...
slick Posted June 21, 2007 Report Share Posted June 21, 2007 Even though you didn't see any carbon buildup, did you clean out the ports anyways? Quote Link to comment Share on other sites More sharing options...
joeld Posted June 21, 2007 Author Report Share Posted June 21, 2007 Yes I did, actually when I had the Intake off I cleaned very well with cleaner and a long stiff brush. And also before I installed the 2nd EGR I disassembled it and did a thorough cleaning on it. thanks Quote Link to comment Share on other sites More sharing options...
slick Posted June 21, 2007 Report Share Posted June 21, 2007 Hmm.... Something simple, but a must ask: Have you cleared the codes in the ECM? Quote Link to comment Share on other sites More sharing options...
joeld Posted June 21, 2007 Author Report Share Posted June 21, 2007 Yes I have cleared the code probably 10 times over the past 3 months. Sometimes it will take longer than other times for the check engine light to reappear, but eventually comes back on. Sometimes light will flash on for a short time, other times light will come and stay untill key is cut off. The most confusing part of this problem is that this valve is a digital with 3 sol. All 3 sol open a seperate pintle that all flow into the same opening into plenum. Seems like sooner or later a code for sol #2, or sol #1. This is the first time I have been unable to track down a problem with my scan tool. Thanks Quote Link to comment Share on other sites More sharing options...
19Cutlass94 Posted June 21, 2007 Report Share Posted June 21, 2007 I had the same problem on mine. I took the TB off cleaned the carbon off the back of that, cleaned the port with a clothes hanger and intake cleaner, and ran the car with the EGR off to blow all that shit out. Then I bought a new EGr and realized I didnt need one... You can try cleaning the contacts, cleaning the EGR itself ( you know the 3 ports Im talkin about that go into the EGR ) put a new gasket there, check the EGR tube, and if that doesnt work I have two extra EGR's you could buy one for cheap Quote Link to comment Share on other sites More sharing options...
joeld Posted June 21, 2007 Author Report Share Posted June 21, 2007 Thanks for that info. But just be sure are you saying you were getting the same code on just one sol. or were you getting possibly #32 generic code for EGR. Thats why I bought a 20$ used EGR first just to see if it change anything. I figured what would be the odds of a different valve setting the exact same code? That is why I don't gamble for a living! Quote Link to comment Share on other sites More sharing options...
slick Posted June 21, 2007 Report Share Posted June 21, 2007 When I had the EGR code going off, it listed 1 of the 3 valves at one point, the listed the generic EGR code at another point. In all reality, I don't think that I've EVER seen an EGR valve go bad on these engines. It's always been a carboned up port to the intake by the throttle body. Quote Link to comment Share on other sites More sharing options...
19Cutlass94 Posted June 21, 2007 Report Share Posted June 21, 2007 yeah Ive never seen an EGR go bad... its just the carbon build up blockes the passages... I had the same code. EGR solenoid #3. I bought a new EGR and that didnt fix it. I had to clean all the shit that I mentioned before. Quote Link to comment Share on other sites More sharing options...
joeld Posted June 23, 2007 Author Report Share Posted June 23, 2007 Just wanted to say thanks to you guys for the imput. Stopped working on this for a day or so, had to start on daughter in-law's Jetta. No AC or blower motor all of a sudden. Will update on the EGR soon Quote Link to comment Share on other sites More sharing options...
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