Mechanics

FUEL INJECTOR CLEANING

1991 Nissan Maxima

Engine Performance problem
1991 Nissan Maxima 6 cyl Two Wheel Drive Automatic 110000 miles

I have a 91 maxima, low miles considering the age (about 110). One day it just started running very rough, like a cylinder wasn't firing. I don't know enough to diagnose it though. Mechanic said one piston wasn't firing due to clogged fuel injector. Naturally, it's like a million dollars to replace it. I tried some fuel injector cleaner off the shelf (several times), but it hasn't worked. The car isn't worth but $1200 so I don't want to spend much to get it running smoothly - any ideas? I've also changed the wires and plugs but no change. Thanks!
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Ovey
May 10, 2008.



Have them do a fuel injector and rail flush with it on the vehicle see if that clears it up, if not the injector probably wil have to be replaced, before replacing the injector I would check its compression *wet and dry* and compare with the rest, if its lower its not hte injectors.

Blackop555
May 10, 2008.
Thanks for your reply. I found the mechanic's write-up and here is more info. &Quot. Checked cylinder rpm drop and cylinder did not drop. Checked compression and it is 150 psi well within specs. Checked injector pulse and it is pulsing like the other cylinders, checked ignition wire on #4 cylinder and it checks good. Crossed with #5 cyl. Crossed wires at the cap and at the engine. We put them back and cylinder 4 still does not drop. Suspect #4 injector not delivering proper amount of fuel. When we done the compression test the tester did not smell or have any signs of fuel on it. Recommend removing upper intake and further checking injectors. May need to replace the injector.&Quot; This is a quote from the receipt. Does this help? Any suggestions are greatly appreciated. Thanks again!

Tiny
Ovey
May 10, 2008.
Sounds like the only other possible thing is the injector is not uputting out the proper amount of fuel.

Blackop555
May 11, 2008.