95 gm 4.6 surging

[vtwindave]

i have a 95 gm with a 4.6L, 83,000 miles. the engine surges when first started cold. it has NEW plugs,wires,fuel filter, iac valve, no vaccum leaks found, cleaned egr passage & installed new gaskets. also has new crank pos sensor & ignition module. fuel press is good. surging goes away after brief warmup. any thoughts on what maybe causing this????????????????????

[radioman2002]

Possibly a bad or intermittant temp sensor. Not the one for the guage (if equipped) but the one that the PCM uses.

[vtwindave]

i was wondering about that myself, i'll change it and llet u know, thanx

[vtwindave]

well i put in a new temp sensor (for the pmc) and no help still surges when u start it cold and the engine ildes down from startup. any other ideas???????? i was hoping the comp would log a fault and give me the check eng light but no luck.

[cobradude360]

make sure you intake zip tube is connected properly and not leaking also when was the last time you cleaned the maf?

[vtwindave]

i cleaned the maf when i changed the iac, not long ago, the tube is connected ok. do u know if a maf from a v-6 will work on a v-8? i was thinking of getting a maf from junkyard. also, would a aftermarket crank position sensor give you problems rather than one from ford???? thanx

[vtwindave]

after pulling my hair out, it was the ignition module i purchased from auto zone that was causing my problem. i replaced it with a stock ford one i got in a junckyard, problem went away!!!!!!!!!!!!!!