ENGINE RPM FLUCTUATES AT CONSTANT THROTTLE

1998 GMC Sonoma

Tiny

Ian Nordman

August, 12, 2011 AT 4:41 AM

I have a 1998 gmc sonoma with a 2.2 litre 4 cylinder engine. I recently had issues with engine hesitating at stop signs so I replaced fuel filter as well as fuel pump like the mechanics had told me that was the issue. Well it wasnt the issue. I later found out that I had a cracked spark plug. So I replaced plugs and wires and problem went away but I have noticed the engine rpm fluctuates at constant throttle. Engine is throwing no codes and have replaced o2 sensors, map sensor, air temp sensor, throttle body cleanup has been performed, and tps sensor within the past year. I have also checked fuel line pressure and it reads within recommended specs. Transmission has also been rebuilt a couple years ago. Please help

FOUND 579 RELATED QUESTIONS

Throttle Problem

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3 Answers

Tiny

rasmataz

August, 12, 2011 AT 8:53 PM

Go to this link for more information: http://www.2carpros.com/articles/engine-surges

Tiny

Ian Nordman

August, 14, 2011 AT 7:06 PM

I found a vacuum line that was old and cracked. Replaced line and problem seemed to go away. Thank you for the help.

Tiny

rasmataz

August, 14, 2011 AT 10:49 PM

You're welcome

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