sr running on 3 cylinders

[Jgrand03]

my s13 blacktop is running on 3 cylinders it did it about a week back so i changed the first injector which solved the problem and now its doing it again

things ive checked/changed

injector is getting signal
changed out all o-rings on new injectors
changed fuel filter
new injector
coilpack



now why would it work for a couple days and then again shit out on cyl. 1

[SoguRacing]

check the harness or relay. there could be a short. check for continuity in the harness and move the harness around. also, make sure that the harness isn't getting too hot as heat increases resistance and could cause problems in wires.

[J40sx]

Low compression,
maybe your piston rings are fried?

[SoguRacing]

sounds more like an ignition problem to me. bad piston rings wouldn't cause an injector to go bad. he replaced it with a new one and it went bad again. something in the wiring harness/ecu.

[Jgrand03]

the car was running fine all day today and yesterday its not a compression problem

[J40sx]

This happened to my brother with his sr...
The motor lagged like crazy.
He would stall just reversing.
The exhaust would have irregular popping sounds during idles.
When we checked the spark plugs the one cylnder that was
not working was black while the others were fine. Then we replaced the spark plugs and it turned black when we checked it again.
He is currently getting a new long block.

Does this sound like the problem you are having?

[Jgrand03]

no sorry thanks for the help tho car was running perfectly fine all day today and last night

[SoguRacing]

do a power balance test just to make sure everything else is right if you can. and to see if the injector is bad ohm it out. check the fsm for the specs. think its like 11 to 13 ohms could be wrong. also, check the wiring harness for continuity. could have a bad diode. this is a must before you can begin to solve the problem

[J40sx]

hmmmm ic
then it could be the ignition.....

good luck with fixing it