Help with cold start surging
Yes I did. Set base spark in drive and geat to 21* and adjusted VE as you suggested. Timing stays right at 21* even when the idle drops. Only thing I notice is when I rev it up and it jumps down to 500 RPM the IAC go to about 100. The Other than that they are at about 50 when the car is warmed up. Would it help if I adjusted the IAF vs ECT tables by montioring the LTIT and STIT?
TECH Fanatic
Joined: Mar 2003
Posts: 1,839
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From: La Porte, TX
Originally Posted by dheck
Yes I did. Set base spark in drive and geat to 21* and adjusted VE as you suggested. Timing stays right at 21* even when the idle drops. Only thing I notice is when I rev it up and it jumps down to 500 RPM the IAC go to about 100. The Other than that they are at about 50 when the car is warmed up. Would it help if I adjusted the IAF vs ECT tables by montioring the LTIT and STIT?
Originally Posted by WS6snake-eater
Yes that is exactly what you need to do
Originally Posted by Blacker
Did you make the adjustments to the timing tables? Also, did you adjust the Main VE Table in the 400/800 and 1200 rpm ranges?
Bill
Originally Posted by Bill Bowling
What adjustments need to be make to the VE table? Do you decrease the values like 60/70/90 percent?
Bill
Bill
needed to stay running.
My opinion is that VE wants to be trimmed up to proper mixture, hot.
Several ways to go about this, I kind of prefer just forcing open loop
and driving around a bit and reading the O2s/RPM/MAP. If you bin
the results up (like by an Excel sort) you can dope out whether you
are way lean, lean, even, rich or way rich at the various cell indices.
The way I worked this on another guy's car was, I made him a debug
tune (disabled all enrichment and disabled closed loop) and had him
go through the logging exercise. Where I saw O2s <0.2 I scaled VE
by 1.2; 0.2-0.3, 1.1; 0.7-0.8, 0.9 and 0.8-up, 0.8X. A few rounds of
this and it seemed to converge to a nice even map. Here I also found
that a big cam (T-Rex) affects the VE actuals negatively, up into the
2000RPM range. Presuming the stock table wasn't already deficient.
After VE is right you may see a different minimum idle airflow needed,
and so on; over-fat needs more air to keep alive than a tight tune.
When the basic VE is right then you can also more sensibly tell just
how much OLFA cold enrichment you really need or can tolerate.
