idle ??
Thread Starter
Heel & Toe
Joined: Aug 2002
Posts: 22
Likes: 0
From: Indian Trail NC
idle ??
HELP.. 1990, polo green and saddle, 87k
idle surges up and down. if in drive stopped at a light at time drops low enough to stall. will start right up again, no problem. once driving again no problem runs great. i've installed the following to no evail, egr valve, o2 sensor, iac, injectors and fuel system cleaned, maf sensor, plugs, wires, cap, coil, fuel pump and filter, catalytic converter, and shows no codes. two mechanics have checked it out, one was at a chevy dealer, they said they checked everything?? also has a power chip if that matters. at my wits end, any help would be appreciated.
Legs
l
idle surges up and down. if in drive stopped at a light at time drops low enough to stall. will start right up again, no problem. once driving again no problem runs great. i've installed the following to no evail, egr valve, o2 sensor, iac, injectors and fuel system cleaned, maf sensor, plugs, wires, cap, coil, fuel pump and filter, catalytic converter, and shows no codes. two mechanics have checked it out, one was at a chevy dealer, they said they checked everything?? also has a power chip if that matters. at my wits end, any help would be appreciated.
Legs
l
Melting Slicks
Joined: Dec 2004
Posts: 2,954
Likes: 2
From: Obama=death for America
I find it hard to believe that when your car is stalling, no codes are being shown. Even if you don't get an idiot light to come on, the problem will be in the memory and the dealer can hook up his little gizmo and check for what's being stored. If the dealer did this already and found nothing in memory, I'd go back to the original chip and see if that fixes your problem. Those chips "off the shelf" are mass produced and don't really do much. You might have gotten one with a flaw. It can't hurt to try. At least it's somewhere to start.
You've already changed all the parts that I would think would or could cause the problem you're experiencing. I'm not sure where the fuel filter is on a 90, but if it's readily accessible, I'd check to ensure all the fittings and the fuel lines going into it are tight.
You've already changed all the parts that I would think would or could cause the problem you're experiencing. I'm not sure where the fuel filter is on a 90, but if it's readily accessible, I'd check to ensure all the fittings and the fuel lines going into it are tight.
Melting Slicks
Joined: Oct 2004
Posts: 2,510
Likes: 4
From: Austin Texas
Originally Posted by legs
HELP.. 1990, polo green and saddle, 87k
idle surges up and down. if in drive stopped at a light at time drops low enough to stall. will start right up again, no problem. once driving again no problem runs great. i've installed the following to no evail, egr valve, o2 sensor, iac, injectors and fuel system cleaned, maf sensor, plugs, wires, cap, coil, fuel pump and filter, catalytic converter, and shows no codes. two mechanics have checked it out, one was at a chevy dealer, they said they checked everything?? also has a power chip if that matters. at my wits end, any help would be appreciated.
Legs
l
idle surges up and down. if in drive stopped at a light at time drops low enough to stall. will start right up again, no problem. once driving again no problem runs great. i've installed the following to no evail, egr valve, o2 sensor, iac, injectors and fuel system cleaned, maf sensor, plugs, wires, cap, coil, fuel pump and filter, catalytic converter, and shows no codes. two mechanics have checked it out, one was at a chevy dealer, they said they checked everything?? also has a power chip if that matters. at my wits end, any help would be appreciated.
Legs
l
1) except TPS (Throttle Position Sensor,but code check indicates it's OK)
2) Clean, clean, clean your TB?
3) Check all manifold hoses for air leak(this would be my #1 thing to check, 'cuz when your Idle goes Low, you are running lean, too much air in your air/fuel ratio)
That's all I can think of right now, others will chime in...
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Melting Slicks
Joined: Dec 2004
Posts: 2,954
Likes: 2
From: Obama=death for America
Originally Posted by legs
Thanks, the chip was in it when I bought the car three years ago, I didn't get the original. I may have to order a stock chip and see what happens.
It sure sounds like the TPS is whacko. That's the newly coined professional terminology for, "Houston we've got a problem here."
Melting Slicks
Joined: Oct 2004
Posts: 2,510
Likes: 4
From: Austin Texas
Originally Posted by legs
Don't know what the reading is I'll have to check.
thanks
thanks
How long has your idle been erratic? Since you bought it, or recently. Maybe you should take it to a shop that specializes in Vettes, or just get a second opinion from a reputable/certified mechanic...
Team Owner
Joined: Sep 2001
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From: Athens AL
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The ECM can technically cause it, but its the very last thing you should think about, that should not be your problem.