signs of bad CAS?

[forcefed86]

I'd like my idle to be more steady. Timing jumps all over at idle. According to my data logger timing is rock solid at WOT under boost. But at idle with the timing connector grounded it still jumps around a bit. Is this normal? I can tell when you ground the timing connector that it lowers timing. Mine drops to around 5, but jumps from 3-8*. Should timing be totally steady and locked? I have a good quality digital timing light. And I don't think I'm picking up on any of the other plug wires.

Thanks

 

[gofer]

The ECU varies timing at idle to control idle speed, lack of jumping around would indicate a problem. how bad does your idle move in the RPM band?

 

[forcefed86]

The ECU varies timing at idle to control idle speed, lack of jumping around would indicate a problem. how bad does your idle move in the RPM band?

Yes I know.

I'm asking if when you ground the timing connector to set base timing if the timing should be dead steady. I'm assuming it should be. Setting my base timing at 5* is difficult because it jumps +/- 3* the entire time.

With the timing connector not grounded timing usually ranges from 15-18 at idle and bounces around a bit as it should.

Idle is between 800-925 depending if the cooling fan is on, lights are on and the AC is on/off. IAC seems to be working it keeps a relatively stable idle when Ac is turned on etc. (my chip is set for 850 idle)

I was thinking my CAS signal might be a little "jarbled" at low RPM.

Idle is not bad by any means, but I believe it could be better.

thanks!

 

[gofer]

my bad... yea it should float around whatever your trying to set it too i.e. 5*. before replacing the CAS check your ground and make sure its a good one. you might have a small vacuum leak around the TB/IM/VC causing idle to move but timing with the CAS grounded shouldn't move + or - 3*.
hope i was able to help some or atleast verify what you were thinking was the problem.