Whether the engine is cold or warmed up, the engine is hard to start. I have to press the gas pedal to get it to start (like as if it had a carb.). It has MPI fuel injection. 95% of the time it will stall if I don't rev it up a little.
When it warms up a little, the idle surges for a few seconds and then returns to normal. It does this all the time - after engine is warm - every minute or so.
I smell excess fuel in the exhaust after it starts and when it is surging. The exhaust has NO restrictions and Cat is not blocked (don't ask, just trust me there, lol).
Fuel pressure holds steady at 40 psi - does not fluctuate with idle surge.
I have tested the TPS .48v closed 4.7v wide open operates smooth
Replaced distributor with new one with all new parts. Timing is perfect. Plugs + wires are new. Coil is good.
Replaced IAC valve - PCV valve - O2 sensor. No vacuum leaks.
Disconnected the IAC valve, MAF sensor, IAT sensor, TPS sensor, MAP sensor, TCC module - separately - one at a time, during idle surging and the surging did not change. Disconnected battery for 20 minutes and no change in problems.
Something seems to be causing the engine to become too rich with fuel. Any ideas?
Tuesday, April 10th, 2012 AT 12:22 PM