rpms fluctuating

[nAiFk1e]

when my car is at an idle it is fine but when i am driving usually at a steady speed the rpms will fluctuate rapidly... but my vacuum doesnt change when it does this BUt i can feel the car jerk a little. any ideas?

 

[Lofty]

when my car is at an idle it is fine but when i am driving usually at a steady speed the rpms will fluctuate rapidly... but my vacuum doesnt change when it does this BUt i can feel the car jerk a little. any ideas?

How are the plugs/plug wires. Are the gauges dimming in the dash? Do you have a boost leak?

 

[kneipperk]

i had a similar prob, turned out to be my plugs ( i was almost positive my ngk iridiums were still good but i was wrong ) checked everything else and started thinkin it was something major, turned out to be my plugs. do a boost leak test and make sure your not leaking pressure anywhere. fix any little leaks you find

 

[nAiFk1e]

i had a similar prob, turned out to be my plugs ( i was almost positive my ngk iridiums were still good but i was wrong ) checked everything else and started thinkin it was something major, turned out to be my plugs. do a boost leak test and make sure your not leaking pressure anywhere. fix any little leaks you find

i just changed my plugs but i dont remember if this problem was going on before i did it... should i change the plugs, regap them? im pretty sure its not a boost leak btw

 

[Lofty]

i just changed my plugs but i dont remember if this problem was going on before i did it... should i change the plugs, regap them? im pretty sure its not a boost leak btw

Don't change them unless they're fouled! Also check that your plug wires are all good, no arcing. I would regap them into spec. Don't be "Pretty sure" it's not a boost leak, do a BLT, so you know for sure, instead of going on assumptions.

 

[bmx77802]

in some cars such as dsm's, they can run like s#!t if you get a different brand of spark plugs. try some oem sparkplugs and see if that helps you any

 

[91gsdohc]

i have a 1991 gs 2.0l dohc and when im at idle in park or neutral my rpms rev up and down when i bought the car the guy said he replaced the fuel pressure reg but instaled the tubo one and said that was the problem but while he was saying that he pointed to the camshaft angle sensor and also idk this might be the problem the intake air box has a hole in it and the tube that brings the air from outside the car is not connected to the airbox any ideas if any of those problems is it?