I'm at a loss...

[tyroelite]

OK, so I've been having lots of problems with my car running/idling properly. It stalls really easily when it is put into gear unles the gas is in a bit and idles really rough.  I just replaced the plugs and wires and the rear plugs were pretty black while the front looked OK ... little white maybe.  I also just replaced the MAP sensor. I'm getting codes 33, 34 and 43.  After replacing the plugs/wires/MAP it is idling better by far.  Another symptom is that the boost guage only sits at 0, no up or down.  The car is getting boost I think, just not registering it.  I've done a visual inspection of te vac lines and they all look OK from what I can tell but I dont really know how to test vaccum beyond that... I believe it requires a hand pump?  I'm going to try replacing the Crank sensor tomorrow and see what that does.  The only other thing that I know is wrong is that the EGR hose from the exhaust to the sensor is rusted through causing an exhaust leak there that is spewing carbon all over under the throttle body.  Anything else you can guess it might be?  I'm also going to check the sensor on the left side of the plenum... IAT?  mind went blank, cant remember which it is there but that one. lol

[GangstGP]

MAT. manifold air temp. Dealer item.

And check the fuel purge vac. hose. this one was huge for me. ran much better. just cut off about a centimeter of the end off.

It gets hot there above the exhaust. there is the MAP and to the right of thats the fuel purge solenoid with the big hose and plastic hose. Did you replace all the stock vac. tees yet? Vacu-tite makes tite ones.

I don't know if I would drive it until you get that egr hose though.
I guess talk to Jeff and maybe he will hook you up.

I would get a new O2 sensor at the same time you get the egr.Hopefully a three wire O2.(dealer item as well)

[Jeff M]

Another symptom is that the boost guage only sits at 0, no up or down.  The car is getting boost I think, just not registering it......The only other thing that I know is wrong is that the EGR hose from the exhaust to the sensor is rusted through causing an exhaust leak there that is spewing carbon all over under the throttle body.

Those 2 do it for me guessing pretty close that the EGR Tube crack spued hot exhaust under the upper intake and melted the vacuum line that runs to the MAP (and feeds the fuel pressure regulator :shock: so NO BOOSTING this engine till you fix it :!:  Had a local TGP have this same problem, and 2 in emails over the last 10 years, and the rest of what you said seems to follow this as the first thing I would check, just pull off the vacuum hose from the top of the throttle body that feeds down to the fuel pressure regulator and suck on it with your lips (don't really need a vacuum pump as it will leak plenty if the hose is melted open!!), if you can suck air then there is your problem, new vacuum line kit is cheap, if GM don't got them I got like 30 or more I bought a few years back to make sure owners still had these after GM discontinued the part.

Jeff M

[tyroelite]

OK, so I took it all apart today to see what was going on and sure enough, the vaccum lines were toasted under the intake.  I got some replacment hard vaccum line and ran that and I also bought a new crank sensor and installed it.  After I got it all back together, it runs now and doesn't throw any codes but it sometimes idles really badly and still stalls when I brake at stopsigns.  My boost guage now shows vaccum but never reaches anything above 0, only negatives for it.  When I first started it, it idled really well (minus the exhaust leak sounds from the egr hose that will be replaced tomorrow I hope.  The only other issue I had that may be the culpret is the CPS i bought didn't look exctly like the one I took out.  THe one I took out was completely plastic except for the magnet piece sticking out the bottom. (its cracked out from that metal spot in 3 directions on the bottom so I'm guessing its not working correctly)  The one I replaced it with is longer in full size but the distance from where the collar is down to the end on both of them is the same (i think) and the new one has a metal collar around it that the bolt goes through.  Also, the O Ring around it is at a different height from the end than the original part i took out.  I bought a first replacement at Autozone and that one wouldn't plug into the wire harness even so I took it back and got one from local A&A and that one plugged in at least.  SHould the replacement be all plastic or is this new one the right one?  WOuld it fire at all if it were wrong? Why no positive pressure on the boost guage?  aggggh, this gets frustrating sometimes....

[Jeff M]

OK, so I took it all apart today to see what was going on and sure enough, the vaccum lines were toasted under the intake.  I got some replacment hard vaccum line and ran that and I also bought a new crank sensor and installed it.  After I got it all back together, it runs now and doesn't throw any codes but it sometimes idles really badly and still stalls when I brake at stopsigns.

Well then you are welcome for the tip :lol: Glad it helped, and thanks for the update 8) !  After running rich for so long your computer needs to relearn things, though your o2 sensor might be ruined (plugs and combustion chamber might be a bit sooty too till things run proper for a while), and the exhaust leak/EGR cracked will also keep things whacked till those are fixed!

Would it fire at all if it were wrong? Why no positive pressure on the boost guage?  aggggh, this gets frustrating sometimes....

No I don't see no "aggggh" :roll: I see results as you nail down the problems with your car and get closer to running proper again :!:   The sensor you have is just a newer style and is fine long as the car starts!  I would hold off hammering on the car looking for boost until you finish fixing what you know is wrong, too often people jump the gun with painful results (blown pistons etc) so keep walking for now, run later when the car is ready for it :)  8) .  Might be some loose intake hose clamps killing the boost, or the huge exhaust leak from your dead EGR that WILL fry your new vacuum lines if you keep running it this way.

Jeff M

[tyroelite]

Thanks Jeff.

I'm taking it easy thats for sure till I get it all running correctly again.  I'm going to run over to the yard tomorrow and find a replacement EGR/Hose and put that on.  I'll check all of the intake hoses and such to see what might be going on there.  I'm also going to try doing an idle relearn first thing and see how it runs since the battery did die the other day.  Thanks for all your help Jeff.  I'm sure I'll be getting back on here for some more advice or at least to update the situation.

[Jeff M]

Like you, can't wait till our efforts are rewarded with an update of smooth sailing ahead 8) .  These cars ran great once, few areas here and there and they can get back to that state again :) I think these unique cars are worth the efforts, few cars have all they offer 8)

Hang in there, know how it can wear on you waiting to get your baby running right, might not be that far away from being fixed, just helped another owner in emails that was having all kinds of pains, got rebuilt life-time warranted injectors that did not help, got some new GM ones from me and all his problems went away, we were thinking there was some more to fix up since he just got the car and most people sell their TGPs when there are too many issues to fix/can't be found to fix so it was a pleasant surprise for both of us when all it was the injectors :D

Jeff M

[tyroelite]

OK, so here's the deal.  I went to the junkyard today and looked all over for a 3.1 with the vac EGR and couldn't find any.  All the other EGR hoses attached differently than the one I have and they were all rusted to the exhaust manifold so I didn't get one.  I did get an IAT sensor and put that in.  After starting it, it idled poorly for a few seconds but I decided to try the block anyhow. I drove it down to the first stop sign and it nearly stalled (400-600 RPMs) but it did manage to stay running.  Then at the next stop sign another 2 blocks down it stalled. Started right back up and then when I pushed on the gas it surged pretty bad.  By the time I got to the light at the end of that block, it stopped and idled fine.  Turned the corner and headed back and it ran fine.  2 more stopsigns and no problem stopping or idling.  Decided to go out to walmart put it through some city driving and parking lot action and it was fine!  Went to buy gas (2.69 if anyone cares) and it still was fine.  When I first turned the car back on after pumping it idled funny for about 2 seconds and then it wasfine again.  Went back and tried the highway this time and it was fine on there.  It def. still sounds like an exhaust leak and I think the very minor performace lack can be attributed to that but it ran fine.  Gotback to my house and had Autozone do an alt test for me since my battery died the other day and it was fine (almost 14v).  Went back again to my house and it still seems to be fine.  I'm going to let it cool down again for a bit and try starting it up again to see if it was just getting used to new parts and thats whyit was funny to begin with or if it was more because it was cold starting.  Hopefully it will be fixed for good now.

Anyone have an EGR hose they want to sell????