I just installed head & cam for my friend's 2000 TA. I give it a rough tune and doing a 20min rev cam break in. During the rev period I log the engine and found that LTFT & STFT is way off. It happened when the engine detect misfire. The idle is not very stable and sometimes it dies out without giving some gas.

The car is a 2000 TA M6 and mod list is 228/232, ported 241 milled 62cc w/match exhaust port, UD pulley, pacesetter LT, ORY with 3" exhaust, Ford SVO 30#. The intake and TB are bone stock.

What's should I look into my tune?

 

You should fix the misfire FIRST.

FYI you don't need to rev the car for 20 minutes to break the cam in, it's a roller...

 

The thing is, it won't even stay idle. When I fire it up, it just dies out for like couple second. I've to keep giving gas to keep it running.

 

You are going to have to keep it running long enough to get some good logs and see what your fuel trims are looking like and then change your fuel settings. You will probably have to desensitize the misfire system to prevent it from throwing out misfire codes.

 

your timing advance for a bigger cam isnt enough at idle id say.. heres my personal tune that lets my car idle perfectly even with a 244/242

Go to Engine -> Spark Control -> Spark Advance -> Idle Spark Advance -> load this into the In Drive and In Park tables... see if this fixes it!!!

Edit - Just looked at your Power Enrichment... OUCH! Thats lean! Make it like 1.24 or something

 

Why do you always recommend a NA engine set their PE to 11.7? I don't get it, way too rich. 12.6-13.00 is NA range.

 

There are other multipliers and parameters that work with the PE parameter at 11.7. If you leave all the other multipliers and parameters at stock you put the PE at 11.7 in order to achieve the 12.5 AFR range roughly. This is what I have read on the forums at the HPtuners website.

 

That's what not to do. That method is commonly referred to as a dyno tune.

If that airflow model is right, then AFR will be whatever is commanded by the PE table. Sometimes there may be other multipliers that interfere, but they make it richer, not leaner.

 

Yeah let me correct myself, I was not saying to do that, I was merely saying thats why some people put the PE at a different value than that of the AFR they want to achieve, because some other mulitipliers affect it. Its not the correct way to do it though, just a short cut a lot of tuners seem to use.

 

I haven't play with the PE that much. Most of the changes made to MAF and VE and Main Spark Advance (High Octane).