Dassan80z

Yo.

Didn't want to start a thread about this, but I spent all day today scratching my head.

80 280zx na

I replaced the ac compressor on my car, and then started it and it ran like ****, which was amazing since it has run perfect since the day I got it.
It misfires and runs like crap at idle and through all the gears.

I tested the coil, it passed but was leaking so I replaced it with an 8202 msd.

This still did not fix the problem.

I went through the entire ignition test procedure and everything checked out to be correct. Though behind the ICM was badly corroded, so I cleaned it, and greased all the connectors making sure they were tight. the cap, rotor and wires are all good. pick up coil around 375 ohms, inside of dist is slightly dirty. The sensor next to the dist that controls the injector fan, it's lead is broken off, has been that way. I can ground it before driving far tho, so not too much of a problem. I was thinking the ICM was at fault, but could not find a test for the module itself.

Problem still there. I started wiggling injector connectors and wiring, and got it to get worse, but never better. Took the stethoscope to the injectors and found two that weren't pulsing until i massaged the wires into the right spot. They all have corrosion in them and the boots are dryrotted. I packed them with dielectric grease with no change, I will go get some cleaner and go over them and re grease them tomorrow. But still there is a dead miss somewhere not related to the injectors.

It's just very akward that changing an a/c compressor would spark up a problem like this..... I didn't unplug anything except the one wire to the compressor and have went over anything i could have "knocked loose" in the process and then some. It was running prefect, like a sewing machine before.

Any suggestions as to where else to look would help. Like afm related, or whatever. No vacuum leaks, everything is getting proper voltage, and has proper resistance so far.

I have faith it will be fixed before the weekend is over. Can't be anything too serious.

NismoPick

Just adding dielectric grease doesn't do anything... Dielectric grease prevents metal from corroding / oxidizing. Once the metal is corroded, it's corroded... it needs to be cleaned.

So... you can soak the injector connectors is Lime Away / CLR, or... save yourself the hassle of doing that every few years, and upgrade to quick connects (I've posted about this in other threads):

Dassan80z

I know, didn't have anything to clean them with. I had actually looked at replacing the pigtails with ev1s or something similar, but wasn't sure which ones I wanted, and really just cheaply wanted to clean them for now to see if it helped.

But I'm not sure that's the main problem.

BlueKitsune

Spray the connectors out with some carb cleaner to get the grease out then soak the entire connector for 5min in Tarnex, blast them out with compressed air and spray WD-40 inside them. All done! I've found that to be the best way to clean them out.

Dassan80z

Will be getting back on this first thing in the morning. Thought about using carb or brake clean also. lol, was going to go pick up some electrical connection cleaner. Guess I'll give that a shot first since I've got plenty layin around.!

Dassan80z

IT KEEPS GETTING BETTER.............................


So I had the car idling going back over connections, and fuel injectors.

I decided to pull the dipstick to look at the oil. When I pulled it out the car started running worse. Put it back in it went back to running rough.

Seriously, the ****ing oil dipstick............ I have got to have a bad ground somewhere. But I have gone over all of them in the engine bay.... This is crazy.

I took a video if you don't believe me I'll load it up. Pulling the dipstick with it running and it drops a few hundred rpms and spits and sputters, then goes away when I put it back in............

NismoPick

um... it should do that.

There is a reason for the "PCV valve".

You should try removing the oil fill cap when running...

Dassan80z

Just did, LOL..........

Never had any of my other vehicles react as badly.....

Dassan80z

Did a snap throttle and heard a noise. Got out the stethoscope again and found the pcv to be the culprit. Going to try that and a few more connections.

Dassan80z

Pcv valve was seized. Also found one ground wire I missed that was corroded. A few of the injector clips are in poor shape, had to re-bend one and clean all the connections, that solved the problem!

Since I have to replace the pigtails anyways, is there a good swap for injectors? Maybe out of a supra, or something along those lines that I could find in the junkyard.

Or should I just go with the stockies and ev1s?

N/A, might go turbo later on down the rd.

BlueKitsune

Uh, Nismo posted the upgrade at the top of this thread lol

Dassan80z

I know that, I am getting the quick disconnects...

found some info here.

http://atlanticz.ca/zclub/techtips/injectors/

the audi clips look nice, wonder if i can find any at pull a part.

Looks like I'm going to have to pull the injectors to clean the contacts in them.

Thanks guys.

NismoPick

^^^ Good find.

There's no need to upgrade injectors on a stock n/a motor.

Dassan80z

Not even to 200-220cc (can't find any) with some porting of the throttle body and intake? Or will the stock ecu just not recognize it at all? Been looking at Beck Arnley and they are fairly pricey, msa has a good deal on injectors and seals.

audiofreak97

I redid mine using the GM clips. They fit good, look good, and make life so much easier. For the 1 dollar entrance fee to the yard, I walked up with a hand full of wires and they said 'your good.' 10 connectors w/ plenty of wire for a dollar!

The Audi clips look nice, but would that rubber 'boot' cause fitment issues with the fuel rail? Just curious...

WildmaN

I'll stand by the Beck Arnley's. They are well worth the money. That is what I have been running in my Z's. Go to rockauto.com, and you will find them the cheapest new. That is the parts source I mainly buy from.

Dassan80z

Most likely going with the becks, does rockauto pressure match the injectors if sold in pairs? Can't find anyone local thats up for it. My motor is completely balanced, would like to make the injectors that way also Think I got a lone on a few audis in the junkyard. Going to check them out this week.

WildmaN

Good choice, they should just be all the same. You shouldn't have to pressure match any of them. They all have the same specs.