QuestionQUESTION: I have 93 toyota pickup, 23re engine mt. Aprox 28,000 miles on re-man engine. has miss at higher RPM's between 50-65 mph.Engine compression 150, all 4 cyl dry test, plugs dist cap, rotor, plug wires, fuel filter, check fuel pressure, and regulator ok within specs. TP sensor replaced, ignition coil and igniter. tried known good mass air sensor/ecu/ known good distributor, pulled cyl head, was told at machine shop that it was 30ths below specs. replaced with new cyl head. Still have miss!Check engine light has never come on and no codes in system, light works because it proves out. Any suggestions would be greatly appriciated , before I pull out what little hair I have left!! I was a Master ASE tech for 20 years, But I am at a loss with this!!!
p.s. EGR valve has been replaced also!
Thank You!!
R. Lucas
ANSWER: Hello, the only thing I can think of and that hasn't been replaced yet are the injectors, it doesn't sound to me like it's an electrical issue but there is a chance that there may be higher than normal resistance in the wiring between the injectors and the ECM, a resistance check may turn something up. If not I would give the injectors a try.
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QUESTION: Thank you for replying I forgot to mention that I checked injector ohms ok
took them out and had professionally cleaned and flow tested was told no problem, you say to check resistance on injector wiring is that from injectors to ecm do you know what resistance is normal,
Thank you
Ralph Lucas
AnswerYes the wiring from the injectors to the ECM, there should be no more than one ohm resistance with the connectors disconnected from the ECM and the injectors. While you're there check all the computer ground wires, they're brown black, check them with the connectors disconnected to body ground, there should be almost no resistance.
