Sputtering with Mach 4 Injectors

2-1/2 hours later. No further improvement. I had forgotten all the remedies I had tried to smooth out the APPS issue like grounding straight to the batter, foil around the 2 off idle circuit conductors that was grounded, etc. All of which I unsoldered, and removed putting the circuit back to original, then I removed the square OEM plug, installed crimped butt joints, soldered, and put heat shrink around each. O.B. is being an S.O.B.

It runs great on cruise control (electronic on the 02 so doesn't use the APPS, but is controlled through the PCM), and stutter with the APPS.
 
A good friend let me borrow 2 ECMs. Neither resolved the issue, though with one of the ECMs, there was no issue until after the engine was at operating temp for an hour.
 
biggy238 said:
Fuel temp?

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Thanks,

I was thinking that maybe the ECM was getting warm enough that circuit parameters changed. I have not tried a brand new ECM, but after trying I think it's either 4 or 5 different used ECMs, I don't think a new one would be any different other than the co$t.

The fuel temperature seems to be alright. The highest fuel temp I remember was in the low 90 degree range measured at the pump. I just started measuring this fall though. That doesn't seem out of line does it?

Highest IAT reported by the ECM was in the upper 100 teens degrees range. I've never noticed at 120. The more I put my foot into it, the cooler they get. Exhaust temps on the other hand ... not so much.

~OB~
 
I was a bit hasty in replying. I still haven't had a chance to read the thread in its entirety.

Both Temps seem relatively usual.

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