'87 325 w/ '89 m20b25 motor MISFIRE AT IDLE, rough

[sweet3]

I'm not sure if you managed to fix the problem. But I had a similar problem when I first got my car. Turned out that my harness connector was corroded and the wires had come disconnected. I fixed my problem by getting rid of the old harness connector and soldering a new harness connector located under my intake manifold.

[Ginsterman98]

Easy fix, glad you found the problem.

[mbonanni]

Located my problem.

Injectors 2 and 3 do not spray. I thought it might be the wires so I put wire 1-2 and 2-1 then 4-3 and 3-4. All injectors still sprayed minus 2 and 3.

Thank you

[Ginsterman98]

Let us know what you find. G/L

[mbonanni]

I will doo that, but I think I will rmove the whole rail and crank it to see if all injectors are spraying. Just as much work, if not less, than switching a few injectors. If all spray then I will switch a few.

[Ginsterman98]

Numbers are much better. I would swap a injector from a cylinder that's working and see if the misfire travels with the injector.

[mbonanni]

So compression numbers

1-135 2-140 3-140 4-140 5-140 6-140

I then checked for spark, and cylinder 2 and 3 both have spark.

So what is next, fuel? The injectors are rebuilt m50 ones, maybe there is no signal going to cyl 2 and 3 so they arent firing? I think I will have to go rent a noid light set again and double check.

Any other suggestion on how to check fuel?

[mbonanni]

Just ran car up to about the half way point on temp gauge. It still has the misfire.

I pull all the plugs and eveyrone is a brownish black except cylinder 1 and 2. They are still new looking, no signs of fuel stain or wetness, but then again none of the plugs seemed wet.

I am about to do the compression test.

[Ginsterman98]

Well good luck and keep us in the loop on what you find.

[mbonanni]

Yeah, I think I am going to have to. He is so busy as is work hardly gets done.

I will do it this weekend cause he will be gone.

Friday we are supposed to be checking for spark and fuel to those cylinders..

[Ginsterman98]

Honestly I would just run it for a few minutes without your dad around and see if it clears up.

[mbonanni]

Okay, it idled for about 20 seconds, is that enough?

[Ginsterman98]

Let it idle and it will prime its self. Or disconnect the round connector under the intake manifold, pull the coil lead and remove the plugs. Then crank it for like a minute, that will prime the oil system.

[mbonanni]

Was not able to do anything to the car today, but I did talk to my dad. He does not want to run the car with the misfire, so I guess I will have to double check spark and fuel with working wires and plugs.

I do have a new question. A friend brought this up today.

Do I have to prime the oil etc?

Thanks

[mbonanni]

Okay, I think I will put it all all back and let it run how you said. The motor sat like a month in the car i pulled it from, then about 5 months during the swap process/refresh.

All the plugs were out and throttle was open when test taken, but engine was dead cold.

I bought the injectors from a member on here. They are rebuilt and flow tested, so unless he lied to me and sent me bad injectors, but I don't think this is the case. If you are referring to the fact if i can use m50 injectors, then I also believe I can. I read multiple thread saying m50 injectors are good for stock.

Thank you