92 ranger 4.0 OHV runs on only 3 cyl

[reneg8d]

Hi All,

I have a 92 4x4 ranger with a 4.0 OHV engine.

History: Truck overheated several times. Was delivered to me with reman heads on the front seat, plus a gasket set and new head bolts.

After reassembly, it had no fuel pressure. Replaced the fuel pump. Truck starts, but has a severe missfire. Stethoscope tells me that 3 injectors are not firing. Pulled codes with a voltmeter and got codes 122, 513, and 123. Based on the 513 code, I ordered a reman ECM. NO change after installation... And the same codes are present with the replacement ECM.

I'm desperately hoping somebody out there can point me in a direction to get this girls truck running so she can drive it. I've checked with most of the local shops and none of them have anyone that is old enough to even remember EEC-IV systems and I never did driveability work...

HELP!

Steve

 

[SenorNoob]

Sounds like the 5V reference from the computer is intermittently shorted to ground or power. Check for spliced wires especially around the Throttle Position Sensor.

 

[901wd#2]

Injectors are batch fired, sounds like a bad wire to one batch.