# 95 maxima misfire



## mobil699tech (Mar 11, 2010)

i have a 95 maxima v6 3.0 that i did a tune up on because it was misfiring. once done it was still misfiring on cylinder 4 and 5 so i changed the spark plugs on those again and the same thing happened. i figured it was the coil packs so i replaced those and the same thing is going on. the check engine light is on as well but i can't figure out how to read obd1 codes and everyone i talk to doesn't know how either so any advice would be greatly appreciated.


----------



## 4thGenTinkerer (Nov 1, 2009)

Hi, Welcome to the forums. I was thinking maybe you should check your injectors. Use an auto motive stethescope or piece of tubing to listen to your injectors. Or check the resistance with an volt-ohm meter. If they are making a clicking sound they are working. If not you have your culprit. As for the ones under the intake manifold, you can check the resistance with a volt-ohm meter at a plug on the harness. It is located on the left (passenger side if you are standing in front of the car) side of the engine. Its grey and plugs into the sub harness for the three injectors under the intake. Follow the wires BACK from under the manifold to this plug. Test a known good injector so you have a point of reference. I dont remember the exact number, but if you have three that test the same and one that diff. you know whats up. Also you can go to autozone or advance and they will loan you a code reader. Good luck.


----------



## Dan1120 (Sep 26, 2009)

4thgen gave good advice for checking injector problems, i'll try to help with a couple other areas.

Ok, so this is what you do.

Start the car, get used to the sound of the motor running. While its still running pull out each coil pack individually. When you pull a coilpack off a cylinder that is good, it will start to really misfire. Which ever one causes the least amount of change in the idle and RPM is the problem cylinder. If they all seem to change the RPM by the same amount then it is most likely not a spark problem.

Also listen for vacuum leaks under the hood. They will sound like a hissing noise. If you hear vacuum leaks you need to isolate where it is coming from. Hopefully it will be visible by just looking. If not, get either some brake cleaner or a spray bottle of water. Hose down 1 area at a time until you hear a change in the engine RPM.

When pulling OBD1 codes you usually have a service connector near the drivers or passengers floor board, sorry i'm not sure which side on your car. It should be a two prong male connector. You need to short it out by connecting both terminals with a piece of wire. Then you need to count the blinks on the cluster. It should blink, for example, 3 times, then pause for a second or so, then start blinking again, say 5 times. That would indicate code 35.

I had a misfire on my car, the worst kind, random misfire. I initially thought it was a coil pack or plug. But then I heard a hissing and isolated it to the intake manifold. Removed it, installed a new one, and all was good again. Hope this helps.


----------

