sometimes 2000 rpm idle

[tsin]

hi i have got a problem with idle rpm. after start is idle 2000rpm, after some driving is OK (800-900) and then sometimes back 2000rpm regardless to engine coolant temp..

i think there is a problem with vacuum lines. i describe my connection on images, is it right? or there is different fault?

 

 

http://imageshack.us/f/823/20120205161131.jpg/

http://imageshack.us/f/15/20120205161202.jpg/

http://imageshack.us/f/638/20120205161229.jpg/

[MY1PATH]

Those are correct but You missed a few.Below the Blue on the carbon canister is one more. It runs under the intake tube to a hard line. If you follow that hard line you will find another small vacuum line that goes from the hard line to the manifold near the EGR.

 

Next to the firewall is one that goes the fuel pressure regulator sitting right below the back of the manifold.

 

Check the one going to the brake booster. with the engine just shut off unplug it from the booster side. If you don't hear anything your booster check valve is bad.

 

Check your PCV valve, remove it an turn it over gently in your hand. It should not click when moving it gently. But It should move freely when shaken. (replace if you have any doubts, its only a 3 dollars)

 

Here's the big one, there is a 1" hose coming from the side of your intake tube runs to a hard line under the manifold. This hard line splits into two more large vacuum lines attached your two idle control devices. If either of these 3 lines are cracked or spit or only leak when the engine warms up they will give you troubles. Stretch all the other lines in your fingers to check for cracking as well.

[ejin4499]

Those are correct but You missed a few.Below the Blue on the carbon canister is one more. It runs under the intake tube to a hard line. If you follow that hard line you will find another small vacuum line that goes from the hard line to the manifold near the EGR.

 

Next to the firewall is one that goes the fuel pressure regulator sitting right below the back of the manifold.

 

Check the one going to the brake booster. with the engine just shut off unplug it from the booster side. If you don't hear anything your booster check valve is bad.

 

Check your PCV valve, remove it an turn it over gently in your hand. It should not click when moving it gently. But It should move freely when shaken. (replace if you have any doubts, its only a 3 dollars)

 

Here's the big one, there is a 1" hose coming from the side of your intake tube runs to a hard line under the manifold. This hard line splits into two more large vacuum lines attached your two idle control devices. If either of these 3 lines are cracked or spit or only leak when the engine warms up they will give you troubles. Stretch all the other lines in your fingers to check for cracking as well.

To get to those hard to reach places without removing stuff you might use propane with the engine running and see if it changes pitch. I took a weed burner bell off (it just threads on) and used the wand to gas a potential leak. Just make sure to do it in an open area and let the propane dissipate every now and again.

 

Also a quick way to confirm that there is a vacuum leak somewhere spray a little propane or starter fluid in your intake. If your engine races you have a vacuum leak if it dies there probably is not a leak or it is really small.

Edited February 6, 2012 by ejin4499

[Kingman]

Also wiggle the connection to the MAF sensor next time it's idling high. See if that changes anything.