# Need fuel injector diagnosis help



## bdg (Jan 9, 2006)

Hi all. My 93 Maxima GXE (SOHC) is running very poorly and I need some help diagnosing before I go to the trouble of replacing fuel injectors. 

I have isolated the problem to the #2 cylinder not producing power. I did this by pulling the spark plug wire from each cylinder in turn to see what effect it would have on the running of the engine. Pulling the #2 plug wire caused no change in the way the engine runs. With all other cylinders, pulling the plug wire cause a significant decline in the way the engine ran. I pulled the #2 plug out, attached it to the plug wire, and grounded it in the engine compartment where I could see it and it seemed to be sparking just fine. So that makes me think the #2 injector needs to be replaced. 

BUT, I did the electrical continuity test as outlined in the FSM and the #2 injector tested at about 11 ohms, so that indicates no problem. I also checked the ECM and got no trouble codes. Just the "all normal" code 55. I smell no gas under the hood either. 

So my question to the experts is.....is it still possible that the injector is bad? I would hate to pull everything apart and replace injectors only to find that I hadn't fixed the problem. Any advice?


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## internetautomart (Mar 8, 2004)

bdg said:


> Hi all. My 93 Maxima GXE (SOHC) is running very poorly and I need some help diagnosing before I go to the trouble of replacing fuel injectors.
> 
> I have isolated the problem to the #2 cylinder not producing power. I did this by pulling the spark plug wire from each cylinder in turn to see what effect it would have on the running of the engine. Pulling the #2 plug wire caused no change in the way the engine runs. With all other cylinders, pulling the plug wire cause a significant decline in the way the engine ran. I pulled the #2 plug out, attached it to the plug wire, and grounded it in the engine compartment where I could see it and it seemed to be sparking just fine. So that makes me think the #2 injector needs to be replaced.
> 
> ...


it's still possible the injector is bad
2 things first
1. wiggle the connector ro see if it helps
2. do a compression check on that cylinder


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## alexnds (Oct 1, 2005)

*sent a PM*



internetautomart said:


> it's still possible the injector is bad
> 2 things first
> 1. wiggle the connector ro see if it helps
> 2. do a compression check on that cylinder


I sent a PM to the person with the original post.


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## bdg (Jan 9, 2006)

alexnds said:


> I sent a PM to the person with the original post.


Reply sent to your PM.
thanks


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## bdg (Jan 9, 2006)

internetautomart said:


> it's still possible the injector is bad
> 2 things first
> 1. wiggle the connector ro see if it helps
> 2. do a compression check on that cylinder


Since the problem cylinder is #2, it is almost impossible to even touch the connector, much less wiggle it, but I tried tonight and it made no difference. I also took the plenum off tonight and the connector on #2 seemed to fit tightly and the contacts looked nice and clean and corrosion-free when I removed the connector. 

Also, before I pulled the plenum off, I did check the compression and as it turns out, the compression on #2 is actually _higher_ than all of the others, not lower or the same. The others all came in around 180-190 PSI, and #2 was 210!! I checked it twice just to be sure. According to my manual, that indicates a carbon buildup in that cylinder that I am going to assume is the result of me driving the car over 100 miles with this problem.

Does anyone agree/disagree or have any other comments based on this?
Thanks!


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