tweaked

Hello all,

I need help. My 95 Max came up with a 01 01 code “Camshaft Position Sensor”. I replaced it and the come came back shortly after. The car ran fine otherwise. In the meantime, I changed the spark plugs, and air filter. It still can fine for 1 day. The next morning, when I stated it up, it ran only on 4 cylinder. No other codes than the 01 01. I drove it down to the dealer when I got there, the Cat was red hot from unburnt fuel dumped in misfiring cylinders. They fixed the 01 01 code saying it was a broken connector. They worked on the car for 2 hours (180$) to tell me that they don’t understand why 2 cylinders are not firing. They checked the coil packs, the spark plugs, the wiring and the computer (they tested it with another known good one). It seems that the computer doesn’t see that two cylinder are misfiring. Now I have a car with no codes that runs really bad.

Can anybody help me please? I am at the point where I might have to sell the car in parts if I can’t fix the problem.

Please help me,
Stephane

ny96max

My car did the same $hit to me a while back when i first changed my plugs at 60k. Turned out i had 2 bad coil packs as well. So I just picked up 3 new ones for the rear bank and the car ran perfect!

also, what kinda plugs are you using? you NEED to use NGK Platinum tip plugs as per what Nissan reccomends or else your car will run like crap and probly cause misfiring.

Ant

tweaked

Thanks for the reply. I replaced my "brand new" Bosh spark plugs and reinstalled the old ones. Which are NGKs. I also took the packs from one and replaced it with one from another bank with the same result (ie the same cylinders are misfiring)
Any other thought?

Y-MAX

A quick question: How do you know your car is misfiring when you have no code? And how do you know exactly which cylinder is misfiring? I just changed my plugs and one of the coil pack had a ripped rubber boot? Is there a definite way to test if your car is misfiring other than CEL?

ukmastermind

i had similar prob..turned oput to be a faulty injector on #2

tweaked

Update:

I know it is not:

The coil packs
The wiring between the ECU and the Coils
The ECU
The Ground
The 12V circuit
The spark plugs

I know it is misfiring because it runs really rough and when I unplug the coils in question, there is absolutely no changes in the engine speed. Also, I ran the engine with the coil plugged on a coil tester and there is no sparks at those two.

I even check the voltage from the ECU to the coil while the engine runs, 4 of them have voltage the other 2 not.

Does anybody know if it is possible that the Camshaft Position Sensor doesn't "tells" the ECU when it's time to fire the cylinder that misfire?
The ones that misfire are #2 and #3 (#3, middle one near the firewall and #2, the one in front of the engine towards the radiator)

Any ideas?

Thank you for any help you can provide.

Stephane

CystumMax

You would feel lots of shake coming from the engine, when you have your hand on steering wheel you feel a huge shake, the shakes would be constant.

tweaked

I found my problem! When my mechanic replaced my waterpump, he did not tighten the harmonic balance (Crankshaft pulley) to proper specs. It took about 6 months for the vibration and moving of the pulley on the crankshaft to eat away the crankshaft, sproket and pulley enough to bring the crankhaft position sensor out of phase with the camshaft position... that cause the ECU not to fire those two cylinder. $$$ I am now in the process of replacing the engine.

Thanks for all your help.

dwaku

Unfortunately I'm in the same boat. I purchased my 95 just under 4 months ago with 78,000 miles. Within the first month of owning it I had to replace the fuel injector and the knock sensor in cylinder #2.

And just last night, I got home from work, ate dinner, and went back out to get gas (I was almost on E). When I started my car up it was already warm so the idle went right to 700 rpms and immediately the whole car started shaking.

It was the exact same feeling as when the fuel injector went. When the original injector went I only felt the car shake after I stopped the car and my foot was neither on the gas nor the brake. I guess that's still considered idling. But last night the car shook even while accelerating, and it seemed to feel a little more violent this time, but it's been a while since I felt that shake.

So on the way to the station I'm waiting for a CEL to go on, but it didn't. I got some gas returned home cursing madly in my head. Then this morning I start the car up and it starts up fine, doesn't make any noises and doesn't shake at all. I drive all the way to work (30 miles) and the drive was as normal as usual.

So I called my mechanic and asked if he scanned the computer without the CEL on if it would still tell if there was a cylinder misfire, but he said that without a CEL and since the car is riding fine now that there's nothing he can do to check. So now I'm biting my finger nails hoping I don't have to replace another fuel injector.

When the rough idle happened the first time, I drove my car like that for at least two weeks without having the CEL go on. So I would assume this could be the early stages of another fuel injector failing? But, I'm not sure because the first time it happened there was always a rough idle, it never went away like now. Does that mean that it could be something else like a coil pack going bad?

I just changed my spark plugs to NGK Platinums last oil change, along with my air filter, fuel filter, and drive belts. (I've basically done the 60k service with the exception of the PCV valve, and flushed radiator and ATF-eventually will). So I'm thinking the only other thing this could be, other than a fuel injector is a coil pack. But I'm not a car expert and I don't know if a bad coil pack would make the car run like it's having a cylinder misfire, and if it's common for the shaking to stop for a while. I do know the coil packs are original and I'm at 85,000 miles now.

So my question would be: Could the coil pack(s) be the cause of the shaking while getting gas last night, or is it the beginning of a faulty fuel injector? Any advice would be greatly apprectiated. Thanks.

tweaked

If you want to ensure that you don't have the same problem as mine, remove your accessory belts from around the Crankshaft pulley and see if there is any play. I had some. When I removed the pulley I was shocked to discover that the "key" that retains the pulley and the sproket from turning on the crankshaft was worn out and had eaten away the crank$haft, pulley and $proket. God bless my competent mechanic.