Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum banner
1 - 10 of 10 Posts

·
Registered
2004 chevy trailblazer_ls_ext
Joined
·
1,061 Posts
Discussion Starter · #1 · (Edited)
I had RPMs jumping up and down while i was stopped in Drive a while ago. Fluctuating between 600-900 rpms. I already cleaned the throttlebody last weekend. any ideas?
 

·
Registered
2004 chevy trailblazer_ls
Joined
·
694 Posts
Check for "300" codes, this means you have a missfire of one of the coil packs or spark pugs and will cause this problem. It should throw a code, but I have heard of instances where it didn't. :undecided
 

·
Registered
2002 olds bravada
Joined
·
2,383 Posts
i'm going to assume that you disconnected the battery while you cleaned it?
 

·
Registered
2004 chevy trailblazer_ls_ext
Joined
·
1,061 Posts
Discussion Starter · #5 · (Edited)
yeap sure did.

i went out and scanned but no codes were found. Also put it in drive and got no abnormal idle but it wasnt all warmed up so.
 

·
Registered
2004 chevy trailblazer_ls_ext
Joined
·
1,061 Posts
Discussion Starter · #6 ·
i think im linking the errratic idle with the vibration i am getting. The vibration in the engine compartment only happens in Drive and stopped like at a light. I think it may be the tensioner. i might try to tighten the hex nut thing on the tensioner.
 

·
Registered
2002 olds bravada
Joined
·
2,383 Posts
if RPMs are constant and its just a lot of vibration, it sure can be the tensioner but i was also thinking maybe you got a bad motor mount..
 

·
Registered
2004 chevy trailblazer_ls_ext
Joined
·
1,061 Posts
Discussion Starter · #8 ·
ok guys i need some help. The only thing i have done to it lately is replace the stat and then cleaned the throttlebody. I did disconnect the battery and refitted the 2 hoses and 2 connectors. It will do this no matter if its in Drive stopped or in Park. It will do the fluctuating idle then stop for a few secs then do it for a few and so on. no CEL so far.

Only thing i might try is disconnect the battery for 30mins to reset any memory if that doesnt then remove the intake resonator and TB to see.
 

·
Registered
2004 chevy trailblazer_ls_ext
Joined
·
1,061 Posts
Discussion Starter · #9 ·
UPDATE:

well i disconnected the battery and took off the intake resonator and TB again. all vac lines were still intact. Put everything back and the idle seemed good now. who knows
 
1 - 10 of 10 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top