Mad Jack

Having a problem with a 1995 Grand Am Quad 4 Engine 2.3 L surging at idle and low speeds. Scanner threw an Idle Air Controller code. IAC controller was replaced and that only seemed to bring the problem down to half as bad as it was. Then the MAF was replaced and the TPS, all with no result. Car was also checked thoroughly for vacuum leaks. Still surging (not as bad as before the IAC was replaced but still doing it) and heating up the exhaust. We figure whatever caused the IAC to go out is where our problem lies but we can't find out what it is. We are at our absolute wit's end with this car and the person working on our car is stumped for the moment. Please help if you can.

xeroinfinity

Hey Mad Jack, welcome to AF! Sounds lik you've replaced a bit of stuff there, shouldnt be much left to go wrong.

Hav you checked the fuel filter? and or the fuel pressure/regulator?

If thats not the deal, try testing/checking the coils, they may be shorting out(jumping spark) causing the surge. Hope this helps you out man, If not Haller back.

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1999 Grand Am SS 3.4 OHV

ClassicRockMe

Hello Mad Jack,

I just wanted to clarify the surging you described. I have a '98 SE 4 banger that does that but the brakes also stop working (hit the floorboard). Do you hear a gurgle just before it occurs? Mine does and I know to throw it into Neutral ASAP. I have replced O2 sensor, filters etc. new rotors and pads in front.

Anyone think or heard if it could be the ABS??

Thanks,

ClassicRockMe

xeroinfinity

hey ClassicRockMe , if your pedal goes to the floor you may just need them bled.
IF that doesnt fix the prob, you might need to replace the powerbrake boostr. Good Luck

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1999 Grand Am SS 3.4 OHV

ClassicRockMe

Xeroinfinity, thanks for the info.

Hopefully bleeding will help but I always plan for the worst that way I'm not suprised when it happens!!

handymandp

Try rechecking the intake amnifold again for a vacum leak. It will be a very slight one but enough to cause you problem.