Join Date: Aug 2005
Location: Born in OR. strokin in Texas!
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If it starts then I doubt the COPs are bad (does it even have COPs? I thought 99 was still using coil packs... [Edit: just checked rockauto.com, it does have COPs]). The gas engines start with a baseline program that's stored in the computer. After a few seconds of running they start looking at sensors like the O2 sensor to fine tune the fuel mixture. I would pull the plugs one at a time and compare them to this chart. Also recommend a compression check while in there.
My guess is the computer may be bad, but it's more likely you have a damaged wire harness or a leak in the intake or exhaust manifold, which is causing the engine to lean. Pull the spark plugs if they look like the engine is getting too much fuel then the leak is in the exhaust side, and the computer is adding too much fuel to compensate. if they look normal or lean then the leak would be on the intake side. If the harness is damaged, that gets tougher. You could pull the engine harness and inspect all of it for damage or grab a junkyard harness and hope it works.
For $500 bucks I would jump in with both feet! Worst case grab a junkyard computer and try swapping that in. Check for air leaks, maybe get a new engine/EFI harness. Good luck!
'05 PSD, Silver, SCLW, Torqshift, 4x4 -- Mods: Fast Idle switch, Bullet Proof stage 2 Kit, updated STC
'13 C-MAX Energi PHEV, lifetime milage 53mpg
'85 Mustang Coupe, converting to full electric
'65 New Yorker, white, 4dr.ht., 413cid, 727TF, 400,000 original miles
Last edited by jwiger; 07-22-2012 at 08:04 PM.