Mitch and others have posted a great set of posts to a thread that got started on the engine section. It seems more people look at that section, so I am hoping interested parties will see this and not miss it because it is hidden here in the EFI section.

I got my ProKey, which is the little piece of software that plugs into the USB port on the laptop. This opens every tuning variable on the ECM, many of which are closed on the free down loadable Calmap program that comes with the ECM. Those who have been following this know that the biggest concern right now is getting the engine to start and run reliably through warm up. Things go bad right at 150*ECM so I am searching through the various tables looking for things that are keyed to ECT.

When I data logged through the trouble temp range, I noticed that the timing was getting goofed up. The timing went as low as 0 in one case, and there are no timing values in the main map which are lower than 10. So, this must be the result of trim tables.

One of the tables I have found is an idle spark control. It uses timing to stabilize the idle, and will take out or add timing if the idle goes above or below the target idle speed. The default setting which was in this ECM from the factory removes as much as 5 degrees, and adds as much as 5 degrees through the various warm-up ECT zones. This means a total swing of 10 degees in timig if the idle speed varies as much as 250 RPM. It seems in light of everything that has been written about this so far, that this, and things like it, should just be zeroed out for now, and not be played with until everything else is working better. That seemed to be the essence of what Matt, and Mitch were saying.

I will get back to you in this thread as I discover more tables that are keyed to temp, and ask for thoughts or opinions. Any ideas about what else to look for? I think I will see if there is an IAC throttle follower keyed to a target idle speed which is also indexed to ECT(engine coolant temp). Maybe a certain combination of sensor feedback variables tries to shut the IAC and turn down timing at the same time.

The guy who sold me the ProKey uses this same GEnVII setup on his Mustang 5.0 and loves it. I am encouraged.

Sam

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Sam,

This is an enlightening post. I would suggest turning off ALL automatic feedback functions until you can tune the fuel/spark maps yourself. Those can make tuning the maps to correct "average" values very difficult.

Good luck!

Lou

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Home of Slant6-powered fun machines since 1988

Lou, In order to do tht, I think I must just put zeros in as values, kind of the same way you turn off the O2 feedback on Mega Squirt.
Sam

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