Fuel Injector Issue

My brother is having some issues with his XJ. I tried a search, but I got confused and never really found the answer. So I figured I'd post with his specific situation and hopefully someone will know where to start looking or know how to fix it.

His XJ is a 1996, 4.0L, AW4

The situation:
This past weekend, he changed his plugs, wires, cap, and rotor. The plugs that were in there were, i think, bosch and he said the gap was really wide and they appeard to have been in the motor for a long time.

Once he was done, the motor started to run really rough. It never really ran all that smooth before now, but it was much worse after the tune-up. The check engine light also came on with a "0202" code (P0202 (M) Injector #2 Control Circuit An open or shorted condition detected in control circuit for injector #2 or in the INJ 2 injector bank.)

He took it over to a friends for further testing. With the motor running, he pulled the fuel injector for the #2 cylinder, there was no change in how the motor ran. So he pulled the #4 injector and the motor bogged down. He reinstalled the #4 injector and repeated with the #1 injector with the same results.

They then tested the injector connector. It wasn't reading any ohms whereas the #4 and #1 injectors were reading around 12 ohms. The also tested a little further up the wire with a probe to try to eliminate the possibility of a bad connector but they got the same results.

Any help would be greatly appreciated.

Thanks

Steve

Did he try switching the #2 injector with one of the injectors that appeared to be working correctly. This would tell you pretty quickly if you had a bad injector or a bad wire somewhere.

I had a similiar issue recently only the open circuit was accompanied by a multiple misfire code. My problem was intermittent and when I switched around the injectors the code changed cylinders so 60 bucks later I put a new injector in and the problems been fixed.

As for the truck not running smooth it might be time to clean out the intake manifold, throttle body, and other plugs as they tend to get plugged up over time.

i do not think it is an injector problem. the injector seems to not be getting the singal to fire. they tested the connection before the injector and it isn't reading any ohms on the tester.

wait so it was runnign ok then he replaced the plugs wires rotator/cap and now it runs rough well are wires in the correct positions. did he regap the plugs to the correct spec. are the plugs the correct plugs for the jeep.

yup, yup, yup, and yup. that was one of the first things that i suggested. but then i got to thinking...how would that stuff have any effect on the fuel injector not getting a signal/power to work?

it's wierd. and diagnosing engine problems has never been my forte

sounds like a bad injector to me. Should read ~12 ohms across the injector terminals. if there is no reading that means the injecter has an open circuit.

Checking the wire harness end is done with a test light while the engine is running. it should flash in time with the engine rpms