Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: hollywood on 26 August 2009, 13:20:11

Title: Idle problems
Post by: hollywood on 26 August 2009, 13:20:11

I have had this problem on my car for awhile now and I really need to get to fixing it but just cant figure it out. Im hoping someone can give me a clue.

I have a 2001 catera and When I start it it idles pretty rough where I need to give it a minute to run before I can go anywhere or I have no power. Well even after its up and going and runs good enough to drive when I am in park at an idle with the A/C off the rpms surge up and down up to like 2500 back down to 1000 over and over and over. I went to change out the idle control valve or IAC whatever it is, however mine doesnt even have one. I also have a 1998 catera that is just a parts car and noticed it does have one on it so mine must do something different.

Anyways Wondering if anyone else had this problem and solved it or knows of something I can do to help figure out what the problem is. This problem seemed to start after I changed my valve cover gaskets.

Thanks,
Dave

Title: Re: Idle problems
Post by: Ghost on 26 August 2009, 14:54:18

Have you done the paperclip test to see if there are any codes?
try it and post them if there are any :y
http://www.omegaowners.com/forum/YaBB.pl?num=1189022687

Title: Re: Idle problems
Post by: Andy H on 26 August 2009, 15:28:53

No IAC so DBW (drive by wire). Probably a 2.6 or 3.2 so presumably the paperclip test won't work but 'the pedal test' will?

(Unless Federal OBDII regulations omitted that feature)

Title: Re: Idle problems
Post by: cem_devecioglu on 26 August 2009, 20:18:58

engine idle problems can be really complex..

starting with normal service items change is a good start..

checking for air leaks is another .. breather and plenum gaskets are good candidates..(spraying some carb cleaner around plenum area can give idea )

also exhaust manifold gasket leaks or even a small hole in exhaust system can mislead the ECU with wrong mixture signals..

also lambda sensors are worth checking..

and the list goes on..

Title: Re: Idle problems
Post by: TheBoy on 26 August 2009, 21:33:09

I think all the Caterras are DBW, including the 3.0l ones.

Title: Re: Idle problems
Post by: hollywood on 27 August 2009, 17:09:45

I already tried the carb cleaner around the plenum and didnt find anything there, its really fustrating, I appreciate you guys trying to help.

I tried the pedal trick and mine doest do that, and I guess the paperclip test doesnt work however. I did use a code scanner and got these codes.

P0174 (system too lean(bank 2)
P0171 (system too lean(bank 1)
P1120 (manufacturer control fuel air metering)
P1220 (manufacturer control fuel air metering)
P0507 (Idle control system RPM High)


I guess I can try to see if I can find a used throttle position sensor and put it on and see if that does anything.

Title: Re: Idle problems
Post by: Richard A on 27 August 2009, 17:41:49

Sounds very much like a 'vacuum' problem, go back over 'all' the pipes which may of been moved when the 'cam cover gaskets' were changed, then check every vacuum connector.  :y
regards
richard a

Title: Re: Idle problems
Post by: hollywood on 27 August 2009, 17:43:57

Sounds a little scary however maybe I can find some diagram that shows all the vacuum lines. That would be awesome if thats all it was!

Title: Re: Idle problems
Post by: Richard A on 27 August 2009, 18:20:22

The reason I suggest 'vacuum lines' is I had the very same problem, it was the 'vacuum'pipe which "should" of been connected to the engine crank case breather (from front looking back - left hand side) brass connector with 1/16'' dia hole.
Take your time (it costs zero) look at all connectors.
Vacuum systems are a very common problem with Omega/Catera engines.
Is your Catera engine a 3.2 ?
regards
richard a