intermittant injector??
 

Had a unique issue the other day when moving the cars to my new garage. I started the 944, and it only ran on 3 cyl's. I checked the plugs, and I was getting spark to all 4 plugs, but when I shorted each one individually, #4 wasn't firing!

I turned the car off, and tried re-starting a couple of times, and it still was missing. About an hour later, I tried again, and it fired right up on all 4!?

Anybody had this happen before? (I checked the the #4 injector wire with a noid light, and it was indeed getting signal when it was missing) Just dirty? Am I looking at a new injector in the near future?

Whatca all think?

Thanks
-Nick

You could pull the fuel rail and pull the electrical leads on all the injectors but #4. Put the injector into a cup and crank a few times to see how much (if any fuel) your getting from it.

I would, but it's running fine now...

Make sure the contacts on the injector and the plug going in are sparkly clean..if they are then I'd just bet on gunk from the tank making its way up to the rail.

It's really hard to diagnose a problem on a perfectly running car, isn't it? No way to tell now.

It's not uncommon to have one of the plug wires pull out of the end of the connector. The weather boot will hold it in place. The end of wire connector (threaded to screw into the connector) can also corrode like heck inside the weather boot. Then the ballast in the connector can fail too. But this is very seldom with a stock ignition setup.