Morning Idle problem, again
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Joined: May 2001
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From: Bloomingdale, IL , United States
Car: 1997 Z28
Engine: LS1
Transmission: T56
Axle/Gears: 3.42
Morning Idle problem, again
I have had this problem for awhile, but it is starting to get worse. IN the morning when i start my car, the idle is very crazy. Up and down, up and down. Then it seems like it evens off, so i begin to drive, just to have it die when i come to a stop sign. After a few more minutes of driving it runs fine. I have cleaned my iac valve many times. it seems to act better after a cleaning. Is there anything else i should check, could my valve just be beyond the point of cleaning? Any thoughts guys?
I assume it is the IAC valve, why else would it stumble\die when less air was coming in? A new IAC valve is 98 bucks from GM
The autozone one is only 40, but the plug is in the wrong position.
I assume it is the IAC valve, why else would it stumble\die when less air was coming in? A new IAC valve is 98 bucks from GM
The autozone one is only 40, but the plug is in the wrong position.
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Joined: Mar 2000
Posts: 13,414
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From: Central NJ, USA
Car: 1986 Firebird
Engine: 2.8 V6
Transmission: 700R4
I posted a message on this a month or so ago... I have the same exact symptoms, and it's at its worse on a cold morning. I put my fuel pressure gauge on my car, right before going to Virginia Beach. Standard procedure, put gauge on car, turn key from off to on, watch fuel pressure- should be 42 PSI and holding after the pump stops priming.
The pump primed, and FP dropped right to zero! Yikes! I ran through the rest of the chart, and ended up diagnosing a stuck-open, leaking fuel injector. It could be one of the 6 main injectors, or, for my 85-89 2.8, it could be the cold start injector at the back of the intake manifold. I had the injectors cleaned by Rich J at Cruizin', but hadn't dumped any gas treatment (cleaner, dry gas, octane booster, etc) into the tank since I got the injectors back, so it's probably my own darn fault- Unless, it's the cold start injector.
The bad news is, there's no way to tell which injector is screwed up, unless you pull the rail, and watch the injectors to see which one leaks. I picked up a set of 6 Multec injectors, with fuel rail, for $10 from a junkyard. I'm thinking of sending them out to Rich to be cleaned, and throwing them in.
So it could be a fuel injector... buy/rent/borrow a fuel pressure gauge!
The pump primed, and FP dropped right to zero! Yikes! I ran through the rest of the chart, and ended up diagnosing a stuck-open, leaking fuel injector. It could be one of the 6 main injectors, or, for my 85-89 2.8, it could be the cold start injector at the back of the intake manifold. I had the injectors cleaned by Rich J at Cruizin', but hadn't dumped any gas treatment (cleaner, dry gas, octane booster, etc) into the tank since I got the injectors back, so it's probably my own darn fault- Unless, it's the cold start injector.
The bad news is, there's no way to tell which injector is screwed up, unless you pull the rail, and watch the injectors to see which one leaks. I picked up a set of 6 Multec injectors, with fuel rail, for $10 from a junkyard. I'm thinking of sending them out to Rich to be cleaned, and throwing them in.
So it could be a fuel injector... buy/rent/borrow a fuel pressure gauge!
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Re: Morning Idle problem, again
Originally posted by 9D1BURD
I assume it is the IAC valve, why else would it stumble\die when less air was coming in? A new IAC valve is 98 bucks from GM
The autozone one is only 40, but the plug is in the wrong position.
I assume it is the IAC valve, why else would it stumble\die when less air was coming in? A new IAC valve is 98 bucks from GM
The autozone one is only 40, but the plug is in the wrong position.
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