Engine fails to run in speed density

2000 Camaro with LQ9, L92 heads, 641/615 231/236 112 cam, LS3 intake, rails, and injectors, nick williams 92mm tb, 1-7/8 lt, dual 3 inch.

After loading in injector data, car starts, runs and idles on a stock ls1 tune with MAF hooked up. Wideband is hooked up and working. Set MAF to fail, along with disabling fuel trims in preparation to tune VE tables in SD. Car will fire but immediately dies. Tried bumping idle settings and VE tables around with no change. I've been looking through different tuning guides and searching the forums, but have not found anything yet that will make this car run in SD. As soon as you turn the MAF back on, it starts right up. Any input on this would be greatly appreciated. I've attached the tune files I'm using. Thanks.

Seems to me that you have not failed the MAF properly. The PCM is still looking at the MAF and if you have unplugged it the PCM dont understand what is happening.
P101 P102 P103 needs to be set to 2.

Had the same issue with a friends car a while back. It would run a little bit if the engine was cold but as soon as the temp comes up just a tad it would not idle no matter what I did....until I set all three codes to 2.

I didn't physically unplug the MAF (IAT included in it). My understanding was that you would only need to set the high fail to 0 to kick out to SD. However I did just go out and try it with all three maf codes set to 2, and there is no change.

After a few hours of beating my head against the wall last night, I took a break for a minute. After taking another look at it, I found what was wrong. Turns out there was nothing wrong with the tune, everything was set up perfectly to run in SD. However after reviewing an earlier log file of the car actually running with the MAF still enabled, I found the MAP sensor reading to be the same at all times regardless of engine RPM. I started thinking about how this could be. I then realized that I put a LS3 MAP in, and started doing some research about the differences between LS1 and LS3 maps, and found they are totally different. A quick OS upgrade to 2 bar speed density, edited MAP scaler and offset, and away it it went. MAP started working properly and the car fired right up, in SD, ready to be tuned.

I am at work and can't see your tune but how are your dtc set for the maf?

if you are going to add 2 bar map sensor ,, you need to change your os to 2bar

Still with 2bar mapsensor you can Tune with MAF

if all of your sensors Working good ,, and your Car condition is good ,, i wont turn it to OPEN lope

better to Tune it open and close Lope

good luck

Quote:

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Originally Posted by vette_c6

if you are going to add 2 bar map sensor ,, you need to change your os to 2bar

Still with 2bar mapsensor you can Tune with MAF

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Tuning with MAF using 2 bar option in C5 PCM I tend to disagree. With C6 it seems to be different.

havent tried it ,, usually tuning Gen 4 cars SD

i'll keep that in mind :D

You need to convert it to an sd os scale the map properly also you need to change p0101,0102,0103 to no mil light and uncheck ses enable for it to go into sd mode properly