Have a 94 grand prix V6 3100, Replaced head gasket, intake manifold and since then when I start the car i get a popping or clunking noise from the front end right after starting it, it will pop (Clunk) about 5 or 6 times then idle normally and drive ok. This has been going on now for about 3 months. Now yesterday got in car and started it and got the same sound as usual. When i put the car into drive it is like im still in park or even nuetrul. ev er up and car doesnt move so i throw in back in drive for fear of it jumping into gear to hard. Wait a minute or 2 and put it back in drive and it works no problem. Now im driving but the car isnt shifting out of first, starting to red line. I manually shift it to second, all ok now. So finally make the highway and drives ok all the way. Went to start the car next morning, turns over great but wont start right away, does start and seems ok, once it gets warm i put it in gear and it stalls. I restart it no problem except now its revivg at around 2000 Rpm and stays that way. I let it run for a few mins and nothing changes. I shut it down and restart again no problem. This times its idling at around 3000 and not going down. Seems the warmer it gets the higher it revs. I put it in gear and it stalls. I start it, put in gear barley touch the gas and it stalls. Now whenever i get it to start it stalls near as son as i touch the gas, more pedal i give it the faster it bogs out and stalls. Then sometimes it will just wind over and over and not start at all, then i will try to catch and start winding all over again. Seems when it cold its ok, once its warm no go.But even when its cold it won't take or get its gas it seems. All this started in one day. Also the cooling fans will not come on, temp gauge will hit red and temp light will come on but fans wont. Can all this be related to one thing or am I having an extremely bad day? Thanks in advance.

Check the vacuum line that runs to the vacuum modulator on the trans. If it has become disconnected, that would cause it to not shift automatically. It would also cause a vacuum leak that could cause the hard start, irratic performance, high idle and running hot (due to an overlean fuel mixture) issues.

Check the vacuum line that runs to the vacuum modulator on the trans. If it has become disconnected, that would cause it to not shift automatically. It would also cause a vacuum leak that could cause the hard start, irratic performance, high idle and running hot (due to an overlean fuel mixture) issues.

First thing I did check actually, I was thinking on the same lines as modulator line for the tranny plus vacuum leak. I have double and triple checked all vacuum lines for leaks because to me this is exactly what it sounds like. None are lose, cracked , dissconnected or damaged in anyway. Got me stumped to say the least. I think I will try checking the fuel filter next for the stalling (Possible pump issue to I think). Then I will try changing the TPS for the high idle.I think the fans are because of a bad wire in the back by the ICM, not sure yet tho. Any other ideas feel free to throw them at me plz, I can use them for sure, I NEED MY CAR :1zhelp:

Most of what you're thinking about changing will trip a CEL. Any codes stored? If so, post them here.

Most of what you're thinking about changing will trip a CEL. Any codes stored? If so, post them here.

Any way to read the codes on these cars without a code reader, like the key turn trick or the paperclip in the 2 pins trick?

Any way to read the codes on these cars without a code reader, like the key turn trick or the paperclip in the 2 pins trick?

Answered my own question, I would have had to have the 12 pin connector under the dash which I do BUT it needs to have pins A and B in it, some don't have pin B. Mine was one of the some :( Now I was looking at this code reader and was wodering would it work for my 94 GP.http://www.autobarn.net/eqgmcodread.html It shows only up to 1993 for pontiac except for a few other models, but one of them models has a 3.1 L and I was wondering if maybe this would work with mine where mine is a 3100? Any ideas? I am now getting a lound knocking out of this thing and it will start fine but once warm engine idle shoots up to 2 - 3000 rpm, now after running like this for about 5 mins it will stall itself out everytime.Or if I touch the gas even the slighest little bit it will also stall out. I am also trying to figure out a wire that runs from the right side of my ICM, back small plug not the large front one when facing car, down through my motor and what looks like to my upper rear transmission. It is 2 wires (Yellow and Brown) which look to have taken some heat as the wire casing or protector is all melted from touching my rear manifold.

EDIT: Just wanted to mention that I ran out and dissconnected the TPS and restarted car, same high idle, I then dissconnected the IAC, same, I dissconnected the plug that goes into the air box or near it, was the same, i even dissconnected the EGR plug and still the same thing. If i put it in reverse it will idle down to 1500, if i put it in any other gear it will stall or near stall. This tell you guys anything that would help me out. Thanks again.

Ok, so I found that I had about 1/2 quart of water in my computer, that could possibly be the problem...lol. So my buddy loaned me a computer from a 95 GP 3100 and i tried that. The high rev is now gone and I can actually drive my car again. Only two small problems left. One of the wires going into the computer was corroded bad so I had to dissconnect it, it was a green wire. Anyone know where I can find a site, or link or anything which tells what each wire going to the computer is for or know a way I can test this wire by itself. Coolant fans are still not coming on, maaybe thats what that wire was for..lol. Now the part thats bugging me. No Power. Not like it used to be anyway, maybe this is the green wire, maybe the new (Used computer, or im thinking a totally different problem, I was messing with the throttle cables while taking off the throttle to clean it and the iac and tps. Or i was thinking from the week it was laid up and i was working on it, winding it over and over and playing with different things i did something wrong. I can drive it, Takes a while to get it up to speed but once there drives great. Just don't have that jump from stand still anymore, kind of has to slowly build herself up to speed. While in park i hit the gas and get instant response. When under load say from a stop sign i kick it down the rpms shoot to about 3000 but the car kind of crawls up, no more snap as it had. Any ideas on any of this would be great in helping me finish this problem off, I am now AHEAD of the game for a change :). Thanks for the replies thus far.