377Z

iTrader: (1)

Completely stock 1991 T/A 305 TPI, 730 ECM. Been getting code 43 for a little while. I can feel the ECM take out timing while driving--power gets real soft. Measured voltage of knock sensor circuit with the key on, engine off, should be 4-6 volts but its just under 3V (don't remember the exact number). Also, when testing like this, shouldn't voltage fluctuate when tapping the motor with a hammer, even though its off? Resistance of the knock sensor is within spec. Is the ECM bad? Knock sensor bad?

Also had some other problems, don't know if they're related. When cold the idle would fluctuate--from 400-700 RPM. I figured I'd do some basic stuff like set TPS & IAC. Well, when I put the car in 'field service mode' it didn't want to idle at all and was hard to start. It stunk and the plugs were black, so I know it was RICH. Seemed to run better if I revved it above 1500-2000 RPM, and Was able to pull around on the driveway reasonably normally 5 spd car, though was originally auto & I haven't 'told' the computer yet). Set TPS, Disassembled & cleaned throttle body, verified IAC works, will get new plugs, check/replace cap, rotor, & wires (its due, even if these aren't the cause). Haven't started it yet after the TB cleaning. I don't yet have real scanning capability, to its in the works (as soon as I find a reasonable laptop), I know this will go a long way towards helping in general. What I don't want is to replace stuff that doesn't need replacing, like the computer. I've tried to search the EST trouble code info, but haven't found any threads that directly apply. Sorry for the long read, but wanted to include what I thought was important. Does anyone see anything I've missed or should look at?

377Z

iTrader: (1)

To clarify--the bottom line is:

Is the computer bad if the circuit only measures like 2.87 volts, instead of the 4-6V range?