engine rough when held at a constant rpm

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07-28-05, 07:37 PM

cosmok123

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engine rough when held at a constant rpm

i got an 85 gsl-se and when im just cruising around at a stedy rpm, the car jerks and runs horribly. if i stomp on it it runs fine to about 6k and then theres a goofy vibration for about 200 rpm and its fine again till 7k. kinda 2 questions in one, what could make my car run rough at a steady rpm? and is the vibration anything to be concerned with. im basically a rotor newbie. any advice appreciated thanks...

josh , coeur d' alene ID

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07-28-05, 09:33 PM

Suparslinc

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if it surges, it's probably a vacuum leak

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07-29-05, 12:35 AM

The_7

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Quote:

if i stomp on it it runs fine to about 6k and then theres a goofy vibration for about 200 rpm and its fine again till 7k.

that sounds like some sort of harmonic vibration, is it the same in all gears?

Last edited by The_7; 07-29-05 at 12:49 AM.

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07-29-05, 01:08 AM

The_7

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could it be a bad engine/trans mount, or are they usually associated with a lower rpm band?

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07-29-05, 09:12 AM

impulsive-rx7

I hate this f0rum

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Try some new spark plugs. I have an 85 gsl-se too, and it runs rough like that also when I have about 6 months worth of carbon build-up on the spark plugs. Put some new ones in and it's back to running smooth.