Quote:
|
Originally Posted by Rwillia4
Do you have the ability to see what corrections your EFI is cranking in to get your idle to smooth out.
|
No. ECU is factory - late 1980s to early 1990s mustang 5.0. All I have is OBD1 scanner that will test and flash the codes. I assume the idle air control valve is opening up, to bring the idle up once in closed loop, but maybe not.
It seems like it is buring rich until it goes into closed loop, by smell. The fuel pressure is supposed to drop 1 psi for every 2" of manifold vacuum. With this cam, the idle vacuum is only 14" where a stock 5.0 would be up closer to 20". So the fuel pressure at idle is 33 psi where a stock engine would be more like 30 psi. So I can see where the open loop fuel map is going to be wrong. Then when the idle drops lower and the vacuum drops off more the fuel pressure goes even higher toward 38 psi. I think it is like a snow ball rolling off a cliff.