QuestionQUESTION: Do you know the fuel pressure spec for a 1999 pontiac grand prix gt 3.8L for both when engine running and while off??? thanks
ANSWER: Hey Jake.
Which 3800 engine does this car have The supercharged engine or the regular 3800 engine? The normal pressure on that engine is between 48 PSI - 55 PSI key on engine off it should be to the high side once the engine is running it should drop about 5-6 psi from the high reading. If it has the supercharged engine the pressures are a bit different the low side is more what you would see at idle. the super charged engine has a 2 speed pump. When the blower kicks in the pump runs at a higher speed to stop the engine from running lean and having a melt down. Hope that's what you were looking for. You seem to be fishing for a problem.. I can tell you that the fuel pressure regulators have a tendency to leak on that engine if when the car's running pull off the vacuum hose on the regulator and make sure no gas is leaking past the diaphragm and into the hose. You can also check that after the car has ran for a while and the car has sat for 15-20 minutes pull off the hose and check it then for any fuel present. Hope that helps...
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QUESTION: Fishing?? yeah I'm fishin all right...you asked for it :)
Ok so I leave walmart the other day,(car full of groceries) and i go to start car and it would turn over,start and die. done this for about 15 min. Then I get it to start runs fine for about 3-5 min and stalls driving done the road. Does same thing starts then dies. Wait another 10-15 starts up and drives fine until I got home which was about a 5 minute drive ion the highway at 70mph. Next day drive up to get some chinese 3 blocks away starts and runs fine. I leave starts acting up, same thing. Then had to leave it sit in parking lot til later that night when it started again and drove home. Next take it to a dealer and they say need to change 3 ignition coils, plugs, and plug wires. No way I can afford that kind of money. I pay $165 for parts and change it all myself. Not a mechanic by any means but am extremely confident I did it right. Had a little coaching by a mechanic. Still same problem. today I changed the O2 sensor before the catalyic converter and the fuel filter..although I did not relieve pressure before changin fuel filter....just read was supposed to....again confident with work...problem persists..
was thinking crank position sensor....but taking off crank a little out of my league...although I did unplug it and car just turns over. plug back in....will start and then die....if the car does stay running it is extreemly rough idle...and I have black smoke coming out of exhaust with gas smell...
so yeah Im fishing....and i mean im fishing with worms...no bait because I am just about broke!!!
by the way I have regular no supercharger..never any problems before
thanks a million.,..wouldve never expected that fast of answer!!
Jake
ANSWER: Well Of course you didn't need all those parts. The O2 is not going to cause a start stall condition. The crank position sensor is a possible cause they do go bad often especially if it's got a lot of miles on it... and yes it's involved you need a special puller and the bolt holding the balancer on is on REAL tight. If that sensor was going bad and sending say a higher rpm signal to the module and PCM then yes it would over fuel or vise versa. Again check that vacuum line to the regulator. Ummm This doesn't by any chance have an after market remote car starter on it does it? If it does sometimes they take a crap and interfear with the rpm signal to the pcm thus causing the problem I've seen "scotch lock" connectors on the TACH wire cut through the wire and cause all kinds of weird stuff.. Has the service engine light come on at all? if someone you know has a scan tool where you can look at the data when it will not starts it's a place to start rather than keep throwing parts at this.........
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QUESTION: Ok so I guess im really stuck. Today I checked the fuel pressure and everything was good. the fuel pressure regulator looked fine. no gas coming out to the vaccum hose. I forgot to tell you the other day I checked the ignition module and it was good. You are right about the remote started though. I do have one on the car. Today I disonnected the power to it and the ground and it still acted the same. Dont know if that is enough just to remove the power/ground to remote starter or not. I seen the wire that they say goes to the tachometer and it has a cap on the wire, doesn't go to anything.
The car still has a heavy black smoke that smells of heavy gas coming from exhaust.
There has not been any check engine lights or service engine soon light come on.
I was going to ask you though, if the crank position sensor or the MASS Air Flow sensor goes out, would the service engine soo light come on?????
Also, dont know if unhooking the power/ground to remore starter is enough?
If there was a crack in the head or engine or something of that sorts, would it act up like this???
I had a small amount of smoke coming from behind engine/front of fire wall, but still dont know if thats the wd-40 buring off after I changed the O2 sensor?
Money is tight, stress is wound tighter....
Jake
AnswerWell Jake:
No sometimes removing the power and ground to the start modules are not enough. The Tach wire for the remote starter usually on those engines is tied in at the ignition module to either a white wire or a purple wire That's where it's easy to get to. disconnect it right there at the module is that's where it's tied in. I would personally remove the whole thing and throw it right into the garbage can! They cause more issues then they are worth.Now back to the rest of your question Yes and no both sensors have codes associated with them and they for the most part if they signal they are to put out is skewed way high or way low out of range of what the computer is looking for then yes it will turn on the light. The problem is if it's intermittent or it doesn't do it long enough then no light will light. I don't remember if I had mentioned the MAF sensor to you or not Between the question I get here and what I work on during the day I forget.. But that MAF can act up on those engines as well. with the car running wiggle the connector to the sensor it sits on top of the throttle body assembly if when you wiggle the connector and it cuts out or runs crappy you found it.. Unfortunately there is no real test for the crank shaft sensor... That's about all that I can help you out with via the net. Like I think I mentioned that a scan tool would help you out immensely. Some of the places like autozone and advance will can for codes for free at least if a code set it would lead you to a place to start instead of chucking parts at this. By the way thank you for the rating and comment you sent out ;)
