Engine Reving Question
Thread Starter
On The Tree
Joined: Jun 2003
Posts: 186
Likes: 1
From: Illinois
Engine Reving Question I have a 98 Z28 A4. It has recently started to rev up wildly on it own at random times. Sometimes i will start it up and it will idel fine and i will drive it a few miles then it will act like the throttle is stuck on it and want to idle up at 2000+ RPM. Other times i have started it and it will instantly idle up to 2000+ rpm. I have got out at that time and tried to manualy pull the throttle back and it is already fully back. Any ideas?
Thanks
Thanks
This may not be the problem, but when mine started doing that it was actually the throttle cable.. - The tabs on the Throttle body that hold it were broken so it wasn't tightened and would occasionally get stuck on its own.
On The Tree
Joined: May 2010
Posts: 149
Likes: 3
From: WNY
if the increase in RPM is only at idle I would first look at your MAF. The easiest way to check it out that i've done is by switching mine with a friends for a test. A dirty or failing MAF could cause the ECM to increase fuel raising the RPM at idol yet not be as big a problem as say a stuck cable while driving.
if the increase in RPM is only at idle I would first look at your MAF. The easiest way to check it out that i've done is by switching mine with a friends for a test. A dirty or failing MAF could cause the ECM to increase fuel raising the RPM at idol yet not be as big a problem as say a stuck cable while driving.
Increasing fuel ALONE will stall the engine if air is not increased along with it. Also spark needs to be increased to, or it will stumble and stall.
I agree about the MAF......easy to swap it with another one. But what a bad MAF does is make the IAC valve open and close....causing the increase in rpms.
Air going into an engine...EXTRA air from another source......is the only way an engine can rev up without the throttle blade being open.
.
Trending Topics
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
Five Reasons the Camaro Was the Most Pivotal Player in the Pony Car Wars 2.0
Brett Foote
10 Reasons the LS7 Is GM's Most Extreme Naturally Aspirated V8 Engine Ever
Verdad Gallardo
Increasing fuel ALONE will stall the engine if air is not increased along with it. Also spark needs to be increased to, or it will stumble and stall.
I agree about the MAF......easy to swap it with another one. But what a bad MAF does is make the IAC valve open and close....causing the increase in rpms.
Air going into an engine...EXTRA air from another source......is the only way an engine can rev up without the throttle blade being open.
I agree about the MAF......easy to swap it with another one. But what a bad MAF does is make the IAC valve open and close....causing the increase in rpms.
Air going into an engine...EXTRA air from another source......is the only way an engine can rev up without the throttle blade being open.
