fuel injector problem on 91 G20

[matt trickey]

I tried the Nissan forum but it didn't help. I have a 91 Infinity G20 with a 2.0 Liter. It was running rough and I had a mechanic look at it. He said the fuel injector was bad in the 4th position. He and I both listened to it with a long screwdriver (the old can and string trick) and we both agreed that it wasn't pulling its load. I ordered a new one from Auto Zone, put it in and test drove it around the block. It ran great. The next morning I went to start it up and gas started coming out of the exhaust. When I took the injector back off I noticed the o ring (the small one by the pintle cap) was deformed like it was melting. I put a different o ring on and they keep melting. Also, that cylinder is dead too. The mechanic did a compression test and all was okay so there isn't a hole in the piston. I checked to see if the wire was sending a spark and it is but that cylinder keeps flooding out. I lubricated the o rings and pushed the injector straight down. It seems like it is a problem with the injector but I don't have the tools or the know-how to check if the injector even works. All I know is it did work briefly and now it doesn't.Does anyone know what course of action I could take now? Besides paying an arm and a leg at the shop.Thanks, Matt

[nametakennow]

Kind of sounds like you have an injector with the wrong resistance. I'd double check that Autozone gave you the right one.

[matt trickey]

I'm pretty sure it's the right injector. I actually work at Auto Zone and I'm the one that ordered it.

[nametakennow]

Ah, well there's not better way to do something right than to do it yourself.

I assume you can use some sort of a warranty on it. I'd try a different injector. I can't think of any other reason it'd be stuck open.

[RED_DET]

The problem is you aren't putting some oil around the o rings before you pop them back in the rail. So essentially each time you tried do this you destroyed the o ring and it caused the injector to leak down into the cylinder. Hence the gas coming out of the exhaust. You need to get that problem fixed immediately before you destroy your motor. Gasoline isn't a lubricant and it breaks down the oil. Fix the problem, after you are sure its no longer leaking, CHANGE the oil and put fresh oil back in the car. You may also have to compress the gas out of the cylinder depending on how much is there.

[jodyklintworth]

Hey Matt, I was a manager @advance auto parts for a couple of years.Here's something to try,take a ohm meter with ignition on but not running measure resistence on each plug to check for correct reading I dont know resistence but they should all be close to each other,then check resistence on each injector they should be real close to each other. It is always best to get o-rings like this for nissan you can also flip all the injectors around to see if it is just that spot. P.S. I wouldnt be suprised if you got a bad remanufactured injector that is probably why it got removed from original vehicle