It's been almost 9 months since I got my roadster registered and on the road, but I'm having a heck of a time figuring out why it runs so rich, and idle's so ... lousy. The motor operates fine at driving speed and temperatures, and seems very powerful to me. but once it warms up, the idle drops so low that the car stalls. this is obviously a problem when driving when coming to a stop or slowing into a sharp turn.
I know this isn't a factory five problem, but do you guys have any ideas what is causing this performance issue. I used a 1996 donor car with a the original EFI and ECU from the mustang. I had the the block round bored and rebuilt the block to pretty much stock specs. I'm using the original ford intake manifold, throttle body and plenum. I'm using the FF/hooker headers without cats. No egr. The gas tank is new, as is the gas filter.
So far, this is what I've done trying to fix the idle and rich mixture.
New idle air control valve
new fuel pressure regulator
new upstream 02 sensors
new coolant temp sensor
checked for vacuum leaks but haven't found any.
checked for continuity breaks between all the sensors, but haven't found any
I purchased a BAMA/SCT tuner from American Muscle. BAMA installed a tune which is supposed to take into consideration the EGR delete, cold air intake, side pipes and no cats, but it made no difference. BAMA has asked me to send them a data log so they can review the ECU performance, but I haven't done it yet; I live in the Albany NY area, and it's just been too cold to work on the car outside.
There aren't any shops within 60 miles of here that seem interested or able to do a custom tune.
Thanks for any suggestions.
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