I'm having alot of trouble fixing a bad idle and misfiring during strain in a 1994 Chevy 3.4L FI V6. I've replaced plugs,wires,ignition coil, both oxygen sensors AND ran some Lucas fuel system cleaner/lubricant and it still runs the same! An anylizer pointed to a possible bad IAC valve. Can anyone give me some common symptoms of a bad IAC? I have a feeling an IAC will not fix all of the problem...would like some advice before I invest in one. Thanks to all!
2007-12-15 06:44:19 · 6 answers · asked by ElemEntal 2 in Cars & Transportation ➔ Maintenance & Repairs
First thing to do is to shampoo your engine compartment so you can see things clearly. The decal under your hood should show you where this valve is. Buy some spray Gum-out and thoroughly clean the IAC, also clean the PCV valve and hoses because a leak here will also affect the idle. Also, with engine running, spray Gum-out around fuel injector seals and where intake manifold seals to the head. If the engine RPM changes, then you have a leak to repair.. Also on these engines it is common for the intake manifold to leak a little coolant into the combustion chamber, causing a small amount of coolant to burn along with the gas. If you remove the plugs, one by one, and notice that they are colored differently, this should indicate where the leak is. Good Luck!!!
2007-12-15 06:58:17 · answer #1 · answered by Robert M 7 · 0⤊ 3⤋
Idle Air Control Valve Symptoms
2016-10-07 02:50:20 · answer #2 · answered by ? 4 · 0⤊ 0⤋
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What are some common symptoms of a bad Idle Air Control Valve?
I'm having alot of trouble fixing a bad idle and misfiring during strain in a 1994 Chevy 3.4L FI V6. I've replaced plugs,wires,ignition coil, both oxygen sensors AND ran some Lucas fuel system cleaner/lubricant and it still runs the same! An anylizer pointed to a possible bad IAC valve. Can...
2015-08-14 00:11:44 · answer #3 · answered by Anonymous · 0⤊ 0⤋
You may experience lack of idle control.
The misfire under load would more likely lead me to check the coils on that model but if those are new.... Hmm
Another common cause of misfire on those is the cam position sensor (under the P/S pump) but usually they provide a code. If it is that, after you replace it you will need a decent scanner to perform the crank variation learn procedure.
That intake manifold leak has always been a problem on those but usually the only symptom would be suprise engine damage caused by coolant in the oil.
The good news is that Fel-Pro has finally redesigned the lower intake gaskets to solve that issue. Go get some they are the greatest thing since sex.
2007-12-15 06:59:23 · answer #4 · answered by BFH 6 · 1⤊ 0⤋
Do this an easier way; Go to AutoZone and have them OBD2 check the car. The trouble codes that come out will tell what's wrong. You can buy an OBD2 code reader of your own for little more than what the dealer would charge to use theirs. AutoZone checks for free. If you want to have a conversation with the mechanic, maybe he'd enjoy talking about blueberry pie after he does the diagnosis and fixes what's broken.
2016-03-22 19:04:54 · answer #5 · answered by Katherine 4 · 0⤊ 0⤋
One sign is a fast idle at start up (maybe 2500RPM) even with the engine warmed already
2007-12-15 07:01:06 · answer #6 · answered by Bill 5 · 2⤊ 0⤋
irractic idleling
2015-05-20 11:00:43 · answer #7 · answered by Benjamin 1 · 0⤊ 1⤋