Idle fluctuates. IAC or something else?

[RockinRobin]

Thanks so much help from all of you, the car is now going down the track consistently. I went three rounds Sunday and was dead on dial the 1st two passes....

[RockinRobin]

Mine will start cold with just the starter button, and starts very quickly when warm. Getting very close, but it looks like a cold front is going to keep...

[RockinRobin]

Good info. Thanks Danny!...

[RockinRobin]

Thanks, that did the trick! It seems to like around 10.4 lbs/hr to idle. Still fluctuates slightly. IAC Position is a little low, from 1 to 4%. I guess...

[RockinRobin]

Well I adjusted the IAC Position until it was right around 10% at idle and adjusted fuel lb/hr at idle until I got a range it liked and everything was...

[RockinRobin]

OK new spark plugs (old ones were fouled as AndyF suggested), and fuel pulled down on the cells where it idles. Idle smoothed out and a quick plug check...

[RockinRobin]

OK, I saw that WBO2 sensor in your post and was hopeful that there was a solution for those of us on leaded race fuel. Oh well, I consider replacing the...

[RockinRobin]

So the Sniper cannot use the NTK WBO2 that's for methanol and race fuels?

[RockinRobin]

Danny thanks for the WBO2 sensor info! I just ordered one and will have my Bosch ones as a backup.

[RockinRobin]

Thanks for the advice! I use 110 octane race fuel which is of course is leaded. I keep a couple of new WBO2 sensors in the trailer, the question is how...

[RockinRobin]

Here's datalog of idle from cold start air temp around 60°F. I see the IAC Position stayed high until the 1st time. I blipped the throttle about 2/3rds...

[RockinRobin]

I'll take a datalog of idle today. Thanks again!

[RockinRobin]

Interesting: The secondaries close OK when the engine is off, but if you rev it up slowly, it hangs. If you blip the throttle it closes. FWIW, I think...

[RockinRobin]

Thanks! I thought Sniper 4500 had 8 injectors, or are you referring just to the ones on the primaries? Yeah, I'm a little scared to try to wind that spring...

[RockinRobin]

Thanks! Fiddled with it some and it doesn't hang when engine is off. I had noticed at the track that sometimes the RPM would not come all the way down...

[RockinRobin]

OK I did that and IAC Position is now between 5-10% and the giant sucking sound is gone. Raised Idle AFR by .4, it's liking that too. Noticed that the...

[RockinRobin]

Just ran a test. Cleared the bad part of the Learn Table and disabled learn below 2000 RPM. this seems to help. What should my Closed Loop Compensation...

[RockinRobin]

In my case, no. Fan is controlled manually by toggle switch....

[RockinRobin]

Thanks. Was told I needed 18" of pipe past the WBO2 sensor to prevent scavenging, so I went with 20" to make sure. Disabling Closed Loop down...

[RockinRobin]

This is a Gen 3 Mopar race engine. 13.5:1 compression, high lift race cam, Mopar drag pak intake manifold and a Sniper 4500 on top. Timing is controlled...