Cold idle [Archive] - GrandAmGT.com Forum

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Tank33
10-25-2007, 01:26 PM
Ok, yes I did search, but did not find anything pertaining exactly specific to my situation.

I am just wondering if this is normal. It gets to about -5 here overnight now, when I go to start my car in the morning, it starts, but immediatly goes up to about 1500 RPM, and then every about, 10 seconds it loses a couple hundred RPM. Once the engine warms up, it idles where it should, so I assume this is just a normal cold start procedure?

When I idle with it in gear it feels a little rough and it jumps about 100 RPM back and forth, but it wont do it in P or N. I did find info on this and yes I will try injector cleaning, throttle body, MAF, etc.

Last question. Are the Idle Speed Sensor and the TPS the same thing with a different name, or are they 2 different sensors?

Thanks!

NorKoastal
10-25-2007, 01:44 PM
My car is doing the same thing with the defroster on. less, but still existent with the defrost off. . Im thinking my AC clutch/comprsessor is on its way out.. Recently cleaned my K&N so Im thinking my Maf might have gotten a little dirty...

Im going to schedule a fuel injection cleaning this weekend... Hope it helps.

Sprucegagt
10-25-2007, 02:06 PM
Ok, yes I did search, but did not find anything pertaining exactly specific to my situation.

I am just wondering if this is normal. It gets to about -5 here overnight now, when I go to start my car in the morning, it starts, but immediatly goes up to about 1500 RPM, and then every about, 10 seconds it loses a couple hundred RPM. Once the engine warms up, it idles where it should, so I assume this is just a normal cold start procedure?

When I idle with it in gear it feels a little rough and it jumps about 100 RPM back and forth, but it wont do it in P or N. I did find info on this and yes I will try injector cleaning, throttle body, MAF, etc.

Last question. Are the Idle Speed Sensor and the TPS the same thing with a different name, or are they 2 different sensors?

Thanks!

The cold idle procedure you described is normal. Your idle being rough could be from a number of things, just like you mentioned. If I were trying to fix this, then I would start with the simple fixes like MAF, ISS and TB cleaning then work up from there.

The Idle Speed Sensor and TPS are separate sensors. TPS measures how much your opening the throttle and is normally mounted on the side of the TB. The Idle Speed Sensor controls your idle speed by limiting the amount of air that bypasses the TB blade. It is normally located on the top of the TB.