Originally posted by Halogram:
Replaced fuel pump, car fired up running nice and smooth, 15seconds into startup it died, started it back up, ran 15 more seconds and then dies. The new IAC we put on makin a weird noise, so we put back the old one. wont even fire off old one, Defective new IAC???, Bad TPS? Dont make sense, getting fuel, geting spark, new IAC, new MAF, new gaskets on the upper end, new water pump, new fuel filter, new pcv, quadruple checked the vacuum lines, thinkin maybe we bumped one off, new plugs, new wires, , running out of things to replace here, LOL. Getting the essentials for it to run, but we think IAC may be problem. Any other things to look at? We may be over looking? SUggestons would be apprieciated. Thanks in advance. Ill say this once again, never had a car give me this much problems lol.



The IAC is for idle only with foot off the pedal. Some Zetecs were equipped with a idle air bypass valve also.

When the engine is started it is running open loop. Depending on ECT data and warmup time of the heated O2 sensors, the engine will go closed loop. I would appear that this is when it dies.

To keep from replacing everything on the engine, I suggest attaching a recording scanner and starting the engine with your foot down some on the gas. The sensor data should reflect the problem at 15 seconds.

"Those who cannot remember the past are condemned to repeat it" -George Santayana