ivan84gt

I have a 99 3.8. The car has an odd issue I haven't been able to solve and after reading a myriad of forums cant seem to find an explanation.

When I crank the engine it sometimes take longer than normal to fire up. Sometimes it fires up after a few seconds after I stopped turning the key. Sometimes it start fine but the engine surges to 3000-3500 rpm. It happens cold and hot and entirely random. Sometimes it fires up real quick and strong.

I have a new starter, new alternator, no new fuel pump but have checked fuel pressure and is within spec and it holds fine. New set of plugs and new wires.

The only thing I can imagine is there is something wrong with electronic throttle body or crank position sensor.

The car runs perfectly once it has started. Very smooth idle and smooth acceleration.

What do you guys think? I am going to change crank position sensor but I would like to diagnose, I hate fixing problems by randomly changing parts. Do these engines have a separate TPS or is it part of the electronic throttle body?

Thanks!

GRIDERMAN87

scan the car for codes, see if anything pops up

Evolution223

I think it is true that the pro mechanics with the really good scanners can really trouble shoot fast. If it was me I wouldn't hesitate to take that in to a shop. too complex of an issue for me to figure out.

GRIDERMAN87

its obd2 lots of parts stores have scanners and most will scan for free

BandDirector Blk98ZM6

Just to throw this out there...I had a '96 3.8 that had similar issues. However, if I got out, took the gas cap off and then put it back on and then tried to start it up, it would then start just fine. It happened on several occasions and I never figured out exactly why before I sold it to buy my Z28...

ivan84gt

no codes. I have a an adapter and Proscan on my laptop. I can see all OBDII sensors and everything looks fine when running.

Its just during startup and very random. Doesnt matter if car is warm of cold, sometimes it does it even after warming up.

Just this morning i started up the car and it surged to 3200 rpms then slowly backed down to normal idle.

Throttle body is clean as a whistle.

Its has to be something wrong with the throttle body. Too bad its electronic guess all I can do is switch it out.

Evolution223

but don't you think there is a difference between the $150 piece of junk they use at autoozone and a $2500 professional scanner??

Evolution223

actually my car today took about 1.5 seconds to fire up, turned over like 6 times before it started, it usally starts instantly, it was cold but started perfect yesterday as I drove it a lot, it started fine the rest of today as well.

one time about 5 months ago i parked on a steep mountain for about 30 minutes, and it took like 2-3 seconds to start, it was weird.

I might have a developing issue with this car. Any body have any idea?

csmitty23

Fuel pressure regulator is common to go out on the 3.8.
Fuel leaks through the vacuum line and into the motor causing it to flood, resulting in a few more cranks before it starts.
Pull the vacuum line off at the fuel pressure regulator to see if it has fuel in it. If it has any fuel it will need replaced.

ivan84gt

csmitty thats a good point. I'll check the fuel regulator, it could also be water leaking into the engine. My head gasket is leaking a bit, I put a Bars head gasket leak stop in the coolant and it seemed to have stopped the leaking but it might be possible there is still a small leak into the pistons.

ivan84gt

Finally got a chance to check the FPR and you were right. Its leaking through the vacuum line. Gonna replace it this weekend.

Thanks for the help.

csmitty23

Glad you found the problem. It is a time consuming job so don't try and rush it.

Here is a write up, maybe it'll help.
http://forum.camarov6.com/showthread...sure+Regulator

ivan84gt

Got it done and problem is gone. Thanks!


While doing the job I lost one of the injector clips behind the engine, had to drive to the junk yard to get another. While there I found a z28 with the POSI still in it! Its rare, all camaros are either 3.4's or 3.8's and the few v8's don't have engine, trans or POSI on them. This one was missing the trans and engine but still had the POSI in it, got it for $40!

I guess things happen for a reason, was cursing my self for losing that clip but found a real cheap POSI for the car!

csmitty23

Sounds like things worked out good for you! Some people have all the luck! haha. I'm jk. Glad you got it fixed.