Greetings!
Went to start this 5.0 TC after it sat idle for a week, and it died within 3-4 seconds. Further attempts resulted in similar response. After some initial checks, I was able to keep the engine running by manually depressing the IAC plunger into the barrel. The engine ran fine as long as I could hold that, but stall immediately after release. Codes: TPS out of range; HEGO HO2S sensor out of range-always lean. Bought a new TPS no change.
Today: With the key "on" and engine off, the fuel pressure is a steady 38psi. There is an air release button on the fuel gauge line and when I pushed that, the gauge pressure dropped to zero and does not come back (until you key off and on again). I removed the IAC from its mount and with the key on--I observed the plunger move inside its body--guessing maybe 1/4 inch. I casually checked all the engine management items I see in books and looked at vacuum hoses and couldn't see anything amiss (also climbed on top of this engine and checked the rear--PCV lines etc.). I removed the fuel regulator vac line and observed no fuel leakage there.
Any Ideas? John R
09-18-2012, 01:47 PM
