'86 3G Si - fuel injected obviously - daily driver and currently the only vehicle I have available for use. In the last two weeks it has begun randomly stuttering and trying to die, typically at low to mid speeds (most of my driving is highway speed and usually 40 miles or more with little to no stopping). It will stutter and try to die but if I can keep the gas pedal depressed it will clear itself and go on. If I let off the gas completely it will die but will start right back up with a couple cranks. Between the stuttering episodes it revs fine, runs steady and pulls strong through the gears. Since it was time anyway, I replaced the fuel filter to see what effect it might have but it continues. Two days ago as I left for another 40 mile highway trip home, I got a PGM/FI light that stayed on steady the whole way home but the car ran fine, no stuttering or anything out of the ordinary. I checked the ECU for codes when I reached home and found that lights 2 and 4 were lit. FSM indicates this is a possible issue with the Intake air temperature (TA) Coolant temperature sensor (TW) - which I have yet to locate on the engine! I cleared this light/code from the ECU, replaced the fuel filter and rolled off today to see what transpired...right after leaving home, same thing, stutter-clear-40 mile highway trip with no further issues. On the return trip this evening it stuttered and died 3 times (each time I was in a position where I could not keep on the accelerator) before I reached the highway but started right up again each time. Third time was right at the entry to the highway and after restarting it ran like a top virtually the whole way home save for about six blocks from the house when it stuttered one time only, cleared itself immediately and continued on like nothing had happened. I'm going to assume it will end up being the electric fuel pump (Denso installed new 10/2012) but it sure isn't acting like I'd expect a failing pump to behave? If you've had any experience with these symptoms and can offer anything that will allow me to quickly get this addressed without lengthy test/down time, which I don't currently have, please chime in...it will be greatly appreciated! Thanks in advance to any respondents!
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