engine starts rough; high idle cutout

[jdjj]

My 2002 Impala with 49000 miles cuts out at a high rpm (about 2800) and dies back to about 800 rpm when I gun it in neutral. Also yesterday it started starting a little difficult - a little rough; 1 out of 20 times it will even lock up the engine and the battery will not even turn it over. 1 out of 8 times it is hard on the battery to start. Other times it starts OK and always seems to run fine.

Autozone rep said it is the air control valve. Any help please?

[maxwedge]

Check fuel pressure see if it drops off when the engine looses power, don't gun to much in nuetral you will hit the rev limiter, which engine? Make sure all the grounds and battery terminals are clean and tight, any codes or check engine lites?

[jdjj]

It is a 3.4 engine. Is there a rev limiter on these engines in neutral? Maybe that is what I'm experiencing in neutral. But my wife still has problems with hard starting. At what point do I check the fuel pressure? I am used to a non-electronic carburated engine, but not this type. Thanks.

[BNaylor]

Originally Posted by jdjj

It is a 3.4 engine. At what point do I check the fuel pressure? I am used to a non-electronic carburated engine, but not this type. Thanks.

The 3.4 has a Schrader valve to test fuel pressure on the rear bank fuel injector rail, passenger side of engine. Next to the power steering pump. The test will check the fuel pump, lines, fuel filter and fuel pressure regulator (FPR). With vacuum disconnected on the FPR it should read fairly high at over 60 psi. With vacuum connected around 59 psi. There should be no no more than a 4 to 7 psi difference at the FPR with vacuum connected or disconnected.

[richtazz]

The problem with it turning over is probably a starter going bad. When it happens to stop on the bad spot, the starter dead shorts and won't turn the engine over until it "bumps" around and then it turns over fine. If the car runs ok other than the stalling at hi-revs in neutral, I wouldn't worry about it. That is more than likely the rev limiter kicking in.

[BNaylor]

Originally Posted by richtazz

The problem with it turning over is probably a starter going bad. When it happens to stop on the bad spot, the starter dead shorts and won't turn the engine over until it "bumps" around and then it turns over fine. If the car runs ok other than the stalling at hi-revs in neutral, I wouldn't worry about it. That is more than likely the rev limiter kicking in.

Rich, on this guy's starting problem, if he still has the OEM AC Delco battery and it has never been replaced don't you think it would be a good idea to have the battery checked out first. Just my 2 cents.

I've never had a GM car where the OEM battery made it beyond 50K miles.

[jdjj]

That was my 2 cents worth too! But as I went to Autozone and asked him to check the battery and he even pushed the battery tester cart out of their showroom he said he thought it was the air control valve. I asked him if he didn't think he should check the battery, and he said he didn't see any reason to.
After driving it for 2 more days with it getting harder to turn the motor over (but it ususally started within 2-3 seconds), I took it back and insisted they check the battery. Lo and behold...It had a bad cell!!! A new battery solved the problem.
Hadn't tried to run the rpms up yet.