Please help with MS cold idle issue?
 

It has been cold the last few days so I have been trying to fine tune my PnP MS to run better when it is cool out.

I captured a log from cold start up. The car starts fine although not as easily as with the stock ECU but that is not an issue. It runs like crap when cold and it does not seem to respond to increasing fuel via the cold idle wizard.

Sometimes if I tap the gas pedal it starts to oscillate - revs cycle up/down on their own after I release the gas pedal.

It runs better as the motor warms up but hesitates on light acceleration.

I'm not to good at reading logs but to me it seems as if the A/F go gradually lean very early on as the engine warms up.

I would appreciate any advice given. :bigtu:

Wow, wtf happened in the end. I made a thread on this also a few days ago because I couldn't figure out why I had oscillations like you did. I redid the grounds on my wideband, and messed with the WUE and it's fixed now for the most part. That's all I got : /.

im having this problem to my car was tuned at around 50deg and its like 5, my spark plugs and valves had bad carbon buildup like crazy. clean the spark plugs and then adjust the fuel table and warmup wizard and it stopped idling at 10afrs, it seemes to work on my car but i cant get a good tune going.

Thanks guys !

I don't think my grounds are bad but I'll check again. I have eyelets soldered and all the grounds are common etc.

You really need to post your current .msq with your datalog.

The log shows 2 processor resets, which could be bad grounds.

Thanks Ben ! I really appreciate the help.

The MSQ is attached.

I'm checking into the grounds issue right now but I was told by DIY that I was having COM re sets so I wasn't that worried.

The oscillations appear to be caused by a big lean spot on your VE table. The 19kpa row from 1800-4600 rpm is thin. Try multiplying each of those values by 1.5 and see what happens.

Thanks Ben


Doesn't the ECU ignore the VE table when cold and use the cold idle settings instead ?

No.

Warmup multiplies the VE value. When you have 110 in your warmup, that is 1.1*(VE cell). Most of the other enrichments are turned off during warmup. I believe Gair and AE are the only ones still on.

Got it ! I'll beef up the VE table and report back

Thanks guys!

I had this problem, ended up increasing either the After Start Enrichment values or the warm-up wizard (it was the one with the real-time viewing of O2 output etc and values were 110+). I believe I left most of it at 150-160 at the cold temps which did away with the idle cycles.

Thanks for the tip sicklyscott.

I tried the warm up wizard a few times but it is difficult for me to use... The motor does not seem to respond to clicking on the "increase" tab.
Also each temperature bin becomes ineffective as the next one comes into play.
Sometimes I even smell gas which is sort of confusing if you are expecting that the motor is running lean.

It's a catch 22. You're not going to get augments like CSE and ASE functioning correctly until your VE table is squared away.

That makes sense ...

I'm not 100% sure but I suspect the problems with the VE table were caused by my AFR table - It is also lean in the low KPA area.

Doing some logging and tuning with VE analyzer filters set too low may have eroded the VE table...