Sunset01

I was very happy with my tune except for very cold idle - read whenever I'd start the car this winter. I had the VE tables scaled down pretty good and with the typical recommendations...

I finally logged Air Fuel (commanded I suppose) and saw how right at stone cold startup I was at 10.6 ... the idle would smooth out as it moved into the 11s and beyond... I also could smell the gas even through cats.. though I never was sure that wasn't just a 'feature' of the cam.

Finally went into the 'Fuel enrichment' button which is a multiplier (really a divisor of 14.7/stoich), Baro/map vs. ECT .
I simply scaled a number of the columns down enough so that the multiplier was never above about 1.17 . Worked perfectly - bad cold surging/stumble is all gone.

jimmyblue

iTrader: (11)

I think you're right on the money here.

This (Open Loop Fuel Air Table) is something everybody
with a cam needs to at least check out. The higher your idle
MAP, the worse you will get pushed rich by the stock settings.

I saw a T-Rex car that was idling at MAP or about 60, getting
commanded to run 1.40 fuel air multiplier until closed loop
kicked in. That's about a 10:1 AFR and it idled somewhere
between poorly and not at all until this was made sensible.

Larry

iTrader: (4)

Help me find that Fuel Enrichment button. Are you under Edit, Engine, Fuel control?

Sunset01

Edit, Engine Cal, Fuel tab, Fuel Air multiplier

gtodoug

iTrader: (1)

Cool, I just ran a log for cold starts and my map value at idle seems to float aroud 55-60. ECT were about 60 at start up. I cross referenced the map value with the ECT value and low and behold it was 1.17. My problem is that the idle is stable but I seem to get a little bit of fuel coming out of the exhaust pipes which have ruined 2 pairs of pants already Should I set it any leaner than it already is? I asume the the value 1.17 is about 12.5 afr.

Larry

iTrader: (4)

Under Edit I don't have an Engine Cal. I have an Engine Flow Control but no Cal. I have a 1.6 version. Maybe that's the difference?

Zombie

iTrader: (2)

I changed my openloop f/a in all cells below 140 degrees by pulling 5% of the fuel out. My a/f on cold starts was around 10.3:1 and it had issues idling. After pulling 5% out my a/f was around 11.0:1 and the whole car ran much better.

txhorns281

iTrader: (12)

The OLFA is supposed to be richer at colder ECT for initial startup right??? My table looks like I start out commanding 12.2ish and lean out to around 13.8ish until closed loop fueling begins. I idle around 55-60 kpa as well. It seems that if your VE tables are dialed in correctly you shouldn't start any richer than 11.7ish (assuming your start up ECT is 50 degrees and your idle is 60 kpa and that your OLFA table is stock)

Anyone know if OLFA tables are the same year to year??? I compared a 2000 stock to a 2001 stock and they are exact with the exception of a tiny area that would rarely be reached anyway.

John02SS

iTrader: (47)

Gonna give this a try! Mine has been a bear upon initial startup since I put in the 30lb fms injectors. IFR table is correct and VE tables are 45/55/65/85 to help withe extra injector. Car starts PERFECT after the initial startup. I'm gonna pull 5% on all the tables below where the car goes into closed loop.

For the 1.6 guys, go into edit, engine, fuel control, open/closed loop tab, select ECT vs Map and reduce the values close to or below where your car goes into closed loop. On mine, most IAT's it goes closed at 92 coolant temp. Hope that helps.

Larry

iTrader: (4)

Now this makes sense! Just got my 1.6 version. Thanks...

John02SS

iTrader: (47)

No prob buddy! Be sure to post up results and I'll do the same.

EightBall

Thanks for posting your results, you've helped me out a TON!