Multiple Misfire and Cam Sensor
 

Okay guys.

I decided to start a thread on here b/c I feel not enough people are looking at my nitrous thread to actually chime in on their thoughts. A few weeks back we had a bad misfire while using the nitrous during a data logging session and all the spark plugs were pretty much fried. I replaced the spark plugs and the car started up just fine but the car is running like crap. As you can see by the title those are the codes I am getting when I connect my cipher cable to the computer using uprev. We have checked the new plugs, they are still good, the coil packs are good. I drove it yesterday to move the car b/c we were on the assumption this motor is done but that can't be the case. It starts up just fine, no black smoke or oil in any weird places and no tapping, winding, grinding noises coming from the engine itself. When I drove it she was obviously sluggish but still revved it up to 7grand on each shift and got the car up to 100. Just runs like crap. We are wondering if it could be something on the fuel side possibly bad injectors. Anybody got any thoughts on this?

Well you said you changed the plugs but what about the cam sensor? Is it still throwing that code? Reguardless it most likely is still playing a big part in why it's running sluggish.

I am going to get a new cam sensor and replace it to see if that could be the cause but it is a process of elimination. I do know that w/o the cam sensor in the car will not run. Possibly not functioning right?

this might be something to consider, check your MAF sensors for damage. I am not sure where your spray is in relation to the sensors but there could have been some blowback that damaged them causing you to have the random misfire codes. i would also pull the manifold and look for any possible dirt/burnt gas etc it should be clean if it is not then that may signal something blowing back that could have possibly got to the MAF sensors.

That has already been done and they are good to go. The cylinders that are misfiring are on the driver side front and back.

Have you done any compression and leak down tests?

None, we were gonna do a compression test but the fitting on our cars is very small.

I would start with that. Does the engine shake when idling. Try to get a scan tool and look at the PIDs like o2 and fuel inj etc actually everything, you need spark fuel compression start with one then check the others. Try to take everything clue in and come to a diagnosis.

I would look at your maf sensors or injectors after you replace your cam sensor. It's something that is happening to more than one cylinder, and that's either fuel or air. Anything else I think may be catastrophic. Have you tried logging your vehicle with it running in it's current condition?

No the engine doesn't shake more than normal when idling that we can tell anyways. My buddy said he did all this already and everything check out okay.

Ya my buddy said he did a few data logs and everything turned out fine except don't quote me on this I believe he said the cam sensor was off a little. I just talked to Nissan and they said to replace sensor and it should fix the problem but if it doesn't a compression test is a little over 200 bucks and he couldn't give me a quote on a leak down test b/c he wasn't sure how many hours it would take.

Let us know what you find

I switched out the cam sensor and no change with multiple misfire.