I hope this is posted in the correct area as well as something that hasnt been over a million times. I have been reading like crazy the past few weeks chasing down a few problems in my 85 302 fi and found one discussion of replacing the IDM resistor but misplaced it and for the life of me cant find it. Regardless here is the deal... truck started off with an occational stall at idle (twice in a week) finally stalled and wouldnt start up till it sat for a few hours. get it home and pull codes, 18, 31, 31-evp sensor was faulty and fixed so code gone... the code 18 has been persistant despite old worn aftermarket distributer and icm replaced (napa reman and motorcraft for the new parts). clear codes... drive her around for a few miles and seems to run great everywhere except idle, has what seems like an occational miss that gets worse the longer it sits (stop lights are bad) this leads me to the IDM resistor, found it wedged hidden against the cylander head.. I get that the computer reads that signal as comfirmation that the coil fired and adjusts accordingly. Do these wear out or lose function due to heat? if needed whats the deal with replacing it? local ford dealer had no info and was no help.

 

P.S. AIC is new (1 yr) but it is a BWD or whatever aftermarket brand (was poorer at the time) wires plugs cap and rotor are all good, coil is msd new as of 2011, fuel pump and pressure regulator are new and the in tank pumps are 2010. truck has a failing pollak fuel selector that cross returns and will draw slightly from the tank not selected (new one coming) and the truck has a single function reservoir and no inline filter that I can find (whole new problem)