Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
Hello, my name is***** it rev up fine or act like it has a rpm limiter? Is check engine light on?
I'd start by cleaning throttle body and checking air filter. You can get throttle body cleaner from parts store and use that with a rag to clean out throttle body. At the same time you can clean out idle air control valve which is supposed to maintain idle. Let me know if you would like diagram to help locate idle air control valve or if you have other questions. Thanks.
The iac gets power/ground in pulsations as needed so no way to test without scan tool. You can check resistance on 4 pins to verify 2 pins have about the same resistance. You can also unplug mass airflow sensor to see if that helps if so then clean/replace. Let me know how it goes or if you have more questions. Thanks.
It makes computer run in default setting since it cannot use sensor.
This is definitely a strange problem. Unplug front oxygen sensors and let me know if that changes anything. I'm about to come to a dead end but I can always open up question to see if someone else has some other ideas. Let me know, thanks.
Does holding down gas while shifting into gear help? Did problem come out of no where or slowly get worse?
Holding the throttle opens allows more air into engine, so this points toward a problem with air being let into system. If throttle bore is clean then I'd replace the idle air control valve. Let me know how it goes or if you have more questions. Thanks.