[bigchad]

Hello all, I've been having an issue with my 2001 Grand Prix for 2 months now. The car will start, run for 1-3 seconds, and die. It sounds fine when running. It started on thanksgiving day, the car died and would not start. I ended up unplugging the battery for several hours and then the car started back up and appeared to run fine.

Then one day I was driving home from work and the car died on the interstate and all I could get it to do was start for a few seconds, then it would die again. I ended up calling a tow truck to tow the car home. The next morning the car started up and would idle fine. I took it for a drive, but it died within 3 miles of my house and would only start back up for a few seconds before dying again. I called my brother who tow-roped me back home. I put a new Bosch fuel pump in the car and replaced the fuel filter, but that didn't help. I am getting 45 PSI at the fuel rail, even while the car is dying. The car has been sitting ever since that day and will not run for more than 3 seconds at a time. I am not getting any security lights.

I replaced the spark plugs and wires as the old plugs were in terrible shape, but that didn't help. I have verified that I am getting spark, and that there is fuel spraying from the injectors. I check the crank pos sensor, cleaned IAC, checked TPS and they were fine. I have a MAF low voltage and MAP low voltage code on the computer right now (p0101 and P0107). I tried unplugging the MAF and that made no difference, car still runs for a few seconds and dies.

I believe it has the stock Upper intake manifold because it has Delphi stickers on it. I have a coolant leak of about 1/2 gallon per month, and noticed that there is coolant puddles on the engine like the Upper intake manifold is leaking. Could an UIM leak cause the car to behave as it is? I have parts on the way to replace the LIM gaskets and UIM.

I have also noticed that the vacuum hose that goes to the brake booster is loose in the UIM, like it's missing a gasket or something. But the car will not even stay running if I give it gas, which I think it would even with a vacuum leak.

Does anyone have any other ideas what it could be that keeps my car from staying running?

I really need some help figuring this out as I have to drive a full size conversion van 80 mi per day to work and it's killing me paying for gas.

Thanks in advance.

 

[soocold]

does it run if you disconnect the O2 sensor, sounds like its dying everytime it switches to closed loop fueling. inspect your wiring harnes going to the MAF and the MAP

 

[bigchad]

I went out and did some testing. The MAF has 12 volts and a good ground, but I am unable to check the signal. The MAP sensor has 5 volts and a good ground. I tried starting the car with the O2 sensor unplugged and it did not help.

 

[WilliamE]

Did you try to remove the plugs, unplug the ICM connector, then crank it over a few times, then put them back and see if it starts?
You probably have coolant in the cylinders.

I do not have what all I said in that PM, but you may post it here if you want.

 

[gtx500hp]

I wouldn't even consider running that engine if it does run okay after you clear the cylinders. There has been more than a few members on this forum that had hydro lock. Bent connecting rods just to start. Gotta replace those intake gaskets ASAP.

 

[bigchad]

If it was hydro locked, I think I would have already ruined something. I also don't think the engine would start up for 1-3 seconds like it does. I'll try to pull the plugs this weekend and see, I would like to run a compression test anyway. I need to find someone with the same car and see if their MAF would fix my no start/run issue. I plan to do the Intake gaskets regardless. I just want to make sure it still has good compression first. I'll keep you all posted. Thanks!

 

[WilliamE]

Did you ever get to do a compression test, or see if your MAF was faulty?

Sorry it took me so long to respond back, I have not been around here much lately as the site has died down a bit.

Another thought on the issue, it could be the crank shaft position sensor, the CKP can cause it to die if it looses signal while running.

If you still need help PM me and I can provide links to test the CKP, I'd post them here but the links are from another forum.

 

[bigchad]

She's back up and running!

I got a new MAF on Ebay and the car still started up for a second and died. I tested compression and all cylinders were right at about 150 PSI. I ended up replacing the upper and lower intake manifold gaskets and upper intake manifold. Once that was done, the car started and has been running fine ever since. Not sure if it was getting antifreeze mixed in with the fuel or what.

I've still got a few smaller issues but I'll start new threads for those if I can't find the answers. Thanks to everyone who helped me out!

 

[WilliamE]

I got a new MAF on Ebay and the car still started up for a second and died. I tested compression and all cylinders were right at about 150 PSI. I ended up replacing the upper and lower intake manifold gaskets and upper intake manifold. Once that was done, the car started and has been running fine ever since. Not sure if it was getting antifreeze mixed in with the fuel or what.

I've still got a few smaller issues but I'll start new threads for those if I can't find the answers. Thanks to everyone who helped me out!

Compression test numbers are great if all were close to 150, it sounds like it may have been taking a little coolant into the cylinders, if so you are lucky nothing internal was damaged, did you change out the oil when you were done?

 

[wingnuts104]

i can almost guarantee that your upper intake was cracked and caused a massive vacuum leak as these engines love to do. As William said, did you change oil after lower intake replacement? and flush coolant hopfully? :icon_conf

 

[gtx500hp]

Learned real well about intake vacuum leaks on our 95 Transport 3800.

After swapping injector, wire, plugs, etc. ...GM had trouble with corroding intake manifold trouble.
Last year I replaced the upper with a Dorman intake, and the lower intake gaskets with Felpro. Great gaskets for Series 1 3800 engines.

 

[wingnuts104]

yeah i hate gm intakes. although they make me alot of money at work, so whatever