1999 GTP. Need Mechanically inclined people...help

[DaTT]

The wife's car, 1999 Grand Prix GTP, just started this issue a couple days ago.

The engine will turn over but not start. Then after a few tries it will fire up and run perfectly.

My first thought is the fuel pump might be on its way out, so let's say that it is not that.

 

[DarkManX]

fuel injectors, ignition coils, idle air controller

 

[DaTT]

Injector's maybe, but wouldn't a bad coil cause rough idle...and does the idle air controller have anything to do with start up?

It doesn't start then die...just doesn't start.

 

[jlee]

Injector's maybe, but wouldn't a bad coil cause rough idle...and does the idle air controller have anything to do with start up?

It doesn't start then die...just doesn't start.

Not necessarily. Does it have any issues running at high RPM under load? I ended up replacing a coil (and fuel filter, so I can't be sure which it was) on my '86 MR2 after it was bogging badly above 5000rpm. That solved the problem. It started fine, though.

 

[exdeath]

When you expect it to happen, at the first start of the day, try turning it to "on" and "off" a few times without hitting "start" to let the pump cycle, then see if it starts up in one crank. Check fuel pressure regulator vacuum hose for fuel. Alternately, check fuel pressure first thing in the day, then again at the end of the day and time how much it bleeds down and how fast. It should hold overnight.

If you shut it down once it's running, does it start back up right away? After a few minutes? An hour? Overnight we know it doesn't.

From the description the only thing I can think that would cause it to take more than a couple cranks every day but otherwise run fine is fuel rail/line pressure is bleeding off when it's sitting. Everything else is solid state and wouldn't behave two different ways between 3 crank attempts as it wouldn't have time to warm up and act different, etc. Fuel lines however take a few cycles to repressurize.

 

[DaTT]

Possible crank sensor?

 

[exdeath]

You should be getting misfires and other run time anomalies if it was crank sensor. Try priming the pump a few times, by cycling the key between on then off for a few seconds at a time, before attempting to start and see if that helps. Fuel pressure regulator would be a simple fix. It may be leaking so slowly that it can hold pressure fine while running without affecting mixture enough to cause run time issues, but leaking down to 0 psi over night as well as flooding through the vacuum line.

 

[DaTT]

You should be getting misfires and other run time anomalies if it was crank sensor. Try priming the pump a few times, by cycling the key between on then off for a few seconds at a time, before attempting to start and see if that helps. Fuel pressure regulator would be a simple fix. It may be leaking so slowly that it can hold pressure fine while running without affecting mixture enough to cause run time issues, but leaking down to 0 psi over night as well as flooding through the vacuum line.

Wife left the house after the car had been sitting all day and it started fine....got a call an hour later saying it wouldn't start. Told her to try a few more times and on the the third time it started.

 

[boomerang]

Do as much of the troubleshooting as you can that exdeath spelled out. It's fuel pressure related. It's easy to replace the wrong parts if you don't troubleshoot it properly and for that you need a fuel pressure gage.

It's the regulator or the pump and I'm betting pump. It's a PITA to drop the tank and replace the pump only to find that it really was the regulator so a pressure gage and the proper procedure is pretty important.

Something easy you could try is to locate the relays. Usually under the hood and under a cover. See if there is an identical relay that you can swap for the fuel pump relay. I'm pretty certain you'll find one. That will eliminate a flaky relay causing the pump not to run. It's a longshot but really easy to do.

 

[SparkyJJO]

3.8L engine, correct?

Common cause of this is the fuel pressure regulator. I had a similar issue and it was just the regulator was going bad, letting pressure drop out when it was parked. Easiest way to tell if it is going bad is to pull the vac line from the regulator (with the car off of course) and see if there is any fuel in it at all. If there is, it's bad and needs replaced. And no, it usually won't make the vehicle run poorly. Also, in my case, priming the pump with key cycles before actually cranking didn't really do much.

It takes all of 1 minute to check it.

 

[DaTT]

3.8L engine, correct?

Common cause of this is the fuel pressure regulator. I had a similar issue and it was just the regulator was going bad, letting pressure drop out when it was parked. Easiest way to tell if it is going bad is to pull the vac line from the regulator (with the car off of course) and see if there is any fuel in it at all. If there is, it's bad and needs replaced. And no, it usually won't make the vehicle run poorly. Also, in my case, priming the pump with key cycles before actually cranking didn't really do much.

It takes all of 1 minute to check it.

Will start with this one tomorrow. Thanks.

And yes, 3.8L supercharged.

 

[AMCRambler]

My 91 Honda Accord did this to me for a while. Ended up being the fuel pump relay.

If it was hot out and the car sat in the lot all day at work, id try and start it to go home and it would just crank and crank. I had to let it air out in the cabin with the windows down for like 10 min and then it would start. No CEL or anything to diagnose it. My uncle who works on imports told us to try swapping that out.