What table do I need to adjust to address an issue with rpm "dipping" when I go from neutral/park, to a gear?
The car idles very well in gear and neutral, but as soon as I place it in gear, the rpm drops to 3-400, and usually dies. IF, I can manage to get it to stabilize, it idles fine.
Any suggestions?
Thanks

 

Have you got the running airflow in park/neutral and in gear right? What year is it?

 

It is a 98 C5
I think I have the base airflow pretty close. I eased up on the airflow 1 gram(?) at the time to get the "hunting"/fluctuation out, and then backed it back down when it seemed to be "pulling" a little hard in gear. It didn't change the "dip" I'm getting when I put it in gear.

 

Which software are you using?

 

HPTuners

 

Was gonna have you send me your tune, but that won't work... Not too many tables to help you on the 98's. Log it and see what the timing is doing when you drop it in gear - may be able to make it better by working on the base spark in gear table and possibly the idle underspeed error spark table.

 

work on your Base Running Airflow also, that cleaned up my idle dipping.

 

Can you post a log and tune?

 

Throttle cracker, sir.

Thought you went to the toooner school?

 

throttle cracker has nothing to do with idle dip...
in an auto it can be used to help with idle dip in gear...but not in park/neutral, but its not the solution.

cracker goes to zero as you take it out of gear(or push in the clutch in a manual trans car)
if it gets to 0 before your desired idle rpm...then its not going to help at all

its all RAF and air fuel for idle dip problems

when you do RAF...you have to go back and redo it...
your car learns at a very slow rate...and sometimes it takes 3 or 4 passes till you get it to settle into a place where it doesnt have to learn too far to work properly.

 

Throttle cracker only takes effect when the car moves...

If the stall is kinda tight, there is a fine line between RAF pulling on the brake and dipping idle... like said above, you may have to check the correction a couple times.

I would still look at the spark - I have seen some of them vary drasticly between park/neutral and in gear... bringing the in gear table values up a bit closer to the park/neutral value will help...

 

Throttle cracker does help with A4's when going from park to any gear. I only know because I've used it a million times to help stalling when changing gears in A4's. Tim, raise your cracker in the lower cells and then tell me it doesn't help the stalling...Mmmmk?

What A/F are you seeing in open loop?

 

Thanks a LOT guys.
The background on this, was that when I went FI , I changed to a Z06 MAF (had one with the kit when I bought it) and the car just WOULD NOT RUN with it. The BIG NAME tuner I took it to, just couldn't get it to idle, so, as I just found out just recently while casing some small issues, he MAXED some tables that shouldn't have been maxed, and Zeroed some tables that shouldn't have been zeroed. All it needed was the MAF adjusyed. Once we did that, it ran fine, (with the exception of a high idle when the AC on)
That being said, I will recheck the base airflow, timing tables etc.
As a note, it has a SY3500 stall

 

And just for the record, it is not me he's referring to in this post.

Give me a call if you need any help with it Tim.

 

NO, it was NOT Josh that tuned it!!

Thanks man, I've got the new Meth kit on it and am trying to find time to get it tweaked, especially the "dying" at idle. Just bugs me to spend BIG BUCKS on a tune and find out the tables have been hacked up, and I have to do it myself anyway..

 

I hear ya brother.

Log your A/F in open loop and see where it's at. I'll also email you a config file you can use to help tune your idle air flow tables more efficiently. Too much air, can also cause a problem.