Just Replaced Fuel Injector, It's Dead! HELP!!! - FIXED!!!

[soobrdad02]

Hey everybody, I'm hoping for some opinions on an issue I'm currently having with my '91 Legacy 2.2 n/a awd wagon. I've had a pretty rough idle for a few weeks and tried a few things to no avail. So I finally started pulling the connectors off of my injectors and sure enough found one that, when removed, didn't affect my idle at all. I figured that the injector was dead and that replacing it with one of the spares lying around would solve the problem. Sure enough, after the replacement it ran just fine. I did just swap the old injector for the new using the existing o-rings (I know they need to be new, but I wanted to diagnose it and couldn't wait the week or more for the dealer or any other supplier to get them in.) Thing is, today it went from running fine to running the EXACT same way it did before the replacement. The first thing I thought of was a computer killing the injector, but I'm hoping it's something less serious. Anyone have experience/thoughts/opinions?

[BSOD2600]

did you measure the resistance of the old/new injectors to make sure they're good or bad?

any CELs?

[Legacy777]

Have you tried pulling the connector off that same injector again? It's possible there may be a wiring issue with that injector connector, vs. the injector itself.

[soobrdad02]

Figured that if it's the wiring it wouldn't have worked at all, new injector or otherwise. No CEL, but lots of codes on the under-dash light though.

[Legacy777]

The wiring may be brittle and moving things around could have caused the connection to work again. I'd definitely suggest checking the wiring. Something you shouldn't take for granted with cars of these age.

[soobrdad02]

What's the best way to test the injector wiring? Just grab the wiring behind the connector and pronounce to jiggling?

[Legacy777]

Use a ohm meter and check the resistance of the wire from the ECU to the injector connector and ensure it's zero ohms.

Also check that there is 12v on the other pin when the ignition switch is on.

[soobrdad02]

Will do. I'll keep you guys updated on the outcome.

[soobrdad02]

Just got back in from testing the injector resistance, and primary/secondary resistance on the coilpack, and have so far deduced that both of the coilpacks I have are shot. One of them reads at 1.0-1.1 ohms and the other is at 0.8, of course just over the high end acceptable readings. The injector that was replaced seems to test fine, but still doesn't seem to affect engine performance when disconnected. Would the coilpack in any way shape or form affect injector performance? As for testing the actual connector wiring against the ECU as recommended by Legacy777, I was wondering if there was a diagram/picture that shows what exactly I'm supposed to be testing from the ECU.

[BSOD2600]

Get the 92 FSM which is posted in the stuff you need to know forum... it has all the instructions on testing components, expected readings, etc.

[soobrdad02]

Awesome! Thanks BSOD2600! I didn't even know that was there!

[soobrdad02]

Well I've pulled the intake manifold and replaced the entire harness to no avail. once I had the engine back together and the wiring/hoses all connected, I started her up and I still have the same issue with the same injector. Tried replacing the injector again, still no sucess. This is getting frustrating...is the computer the only possibility left?

[Legacy777]

What about the wiring from the chassis harness to the ECU? Did you check that?

You said you checked/replaced the engine harness, but they're more wiring that could be bad. Do you have a multimeter?

[soobrdad02]

Went to go look into the problem with injector #4 a little further and when I started the car, I noticed a mist behind the car coming from the tailpipe. so I turned her off and checked it out, and sure enough it was vaporized gas (enough floating around to get my hand wet!) What"s going on with this thing!!!

[BSOD2600]

Done a fuel pressure test yet? Sounding like one (or more) of the injector o-rings are leaking and flooding the cylinder. I had this same thing happen to me after getting my 440cc's cleaned by Dr Injector... ended up giving me the wrong o-rings. took a fuel pressure tester to find the troubled injector.

Your exhaust look like this?

[soobrdad02]

After a trip to the junkyard and a replacement of the fuel rail containing injectors #2 and #4 the problem has only seemed to have gotten worse. By "worse", I mean WORSE the car will turn over but only stay running for 30-45 seconds before sputtering down and dying. I'll start the car and she'll rev WAY above normal (the tach reads ~1750 RPM) and then work it's way back down to sputtering before dying. I checked the CEL's and found a #13, #15 AND #17! So it's not just injector #4 anymore, apparently it's also injector #2 and the cam sensor. Anyone have any ideas?

[soobrdad02]

When I last pulled the codes, I was getting one for inj.#2, inj.#4, and a cam angle sensor... So I went ahead and figured that I'd had enough issues with the injectors and decided to scope out the CAS problem. I swapped one out from a spre manifold I have lying around and she started to run again! She was still stalling and idleing really rough, so I got her a bottle of injector-cleaner/fuel-drier and a full tank of gas, and SHE'S BACK! And just as I was about to embark on the quest of multi-testing the ECU! Wanted to say thanks to everyone for their help in this issue and for all of the great info on the forum in general. :smt114HAPPY HOLIDAYS!