Hi ,
I just picked up a 94 Ranger with a 2.3 engine and occasionally I get an intermittent check engine light. When I read the codes, there is nothing permanent, but a code 20 is in memory. I understand this to be a failed cylinder balance test on the number 2 cylinder.

I’m guessing a fuel injector issue or perhaps an ignition module/spark plug/plug wire issue as it is very intermittent. The engine seems to pull strongly and the only drivability issue is a slightly rough idle that doesn’t seem to be when I get the check engine light.

I’m hoping that someone can give me a little more insight. The truck has only 99K miles.

Thanks
Keith

 

Are you sure that's the code you're getting? I don't see 20 in lists of OBD-1 2-digit codes. You're doing KOEO with an OBD1 system, yes? Are you reading codes from the CEL after doing the jumper on the test plugs?

 

I’m using a tester not KOED. The codes 10 20 30 and 40 are cylinder balance failures. Took me a bit to find them in the book that came with my ODB1 tester. They aren’t listed in many sources online. The code is stored in memory since the check engine light is intermittent and no other codes are stored or active.

 

KOEO stands for key on engine off. It's just one of the two testing modes for the ECM. The other is KOER - key on engine running. That's where I've read you can tell the ECM to do a balance test, quick stomp to WOT and let off. I've never run that myself. By tester do you mean a code reader, or something that does more from the test plugs?

I guess the memory has the code 20 recorded from when someone ran a balance test. You might want to clear the codes and see what gets recorded the next time the CEL comes on, or do a new balance test. Your tester probably has a mode for that. I would guess the problem is electrical seeing how it's intermittent, but that could also include the wires to the injectors.