So I have a 2006 G35 Coupe 6MT, and I let my brother take it for a drive about 2 months ago. NOTE: My brother is very poor at driving manual, and to make things worse, I have a 6 puck stage 3 carbon ceramic clutch. My brother drove it around for a bit and decided to try and park it. We were driving up a very steep incline when he tried to park it, and he was struggling to get the car moving. I offered to park it for him, but he insisted that he could park it, so I let him. He ended up stalling the car really bad, and let the car roll backwards about 2 feet, *without putting the clutch in (meaning the engine was still connected to the wheels when the car rolled backwards). He turns the car back on, and it barely manages to turn on, sounding like a tractor. I tell him to get in the passenger seat, and I park the car so I can have it towed home. I tow the car home and use an OBD2 scanner to check for codes, and find a P0300 (Random Cylinder Misfire) code. I have since tried to fix the code by changing the spark plugs, changing the coil-packs, sealing the plenum of any vacuum leaks (I installed a BLOXS plenum spacer a few months before the incident), replacing the camshaft sensors, replacing the crankshaft sensor, cleaning the MAF sensor with MAF cleaner, and clearing the code, but none of these solutions have fixed the problem. I now believe the issue is being caused by the timing chain skipping a gear when the engine was rotated backwards, when my brother was trying to park the car. If someone else has had a similar experience, or has any idea of what the issue might be, then I would very much like to hear their input.

 

I believe it's possible for that to happen if the car/engine rolled backwards. On the Audi forum I frequent that happened to a guy when his car rolled downhill backwards. He had to re-do the timing belt to get the car working correctly.

 

I strongly doubt that was the case, does the engine crank strongly when you try to start it? Have you done a compression test?

 

I have compression tested the car, the lowest compression it had was 148, and the highest was 160, so it's on the lower side of what a VQ35DE should have, but that's still inside of Nissan's 'safe range'. the engine does start quickly too, although it had lots of trouble starting the first few times I started it since the incident.

 

I know in my prior post, I have heard about it happening to someone else with an Audi. But, I also see you threw a parts cannon at it. Did you use OEM sensors, plug all coils into correct spots, etc...

 

Did your check engine light actually come on? How do you know that code was from that incident? Is it running fine now?

 

I did use OEM parts, I would like to believe I plugged my coils into the correct spots as I was very careful through the process, but anything is possible. I doubt I incorrectly installed any of my parts, but I am open to anything at this point. Something else that is worth noting is that the spark plugs were not all firing the same color spark, some were orange, and some were blue; but because they were all getting spark, I didn't pay attention to the difference in color.

 

The check engine light did come on immediately after the incident, and the issue has not been solved, so it's still running poorly.

 

I don't think the color matters as long as it can make the jump.

Is the the only code you are getting? I think Jim Wolf technology has a template you can print out to see if your engine is out of time. You pull the camshaft covers on the timing cover off and put the prints out over it. If the paper marks didn't line up it meant your engine was out of time if I remember right.

How does it run if it starts?

 

when the car does run, it sounds like my friends straight piped Subaru Crosstrek (not good), and the P0300 code IS the only code I'm getting right now.

 

I just had the fuel injectors tested, and the shop that tested them showed that 2 of the 6 injectors were spraying poorly, so I had them refurbished. I will update w/ the results tomorrow when I reinstall them. Fingers crossed!

 

I installed the new fuel injectors, and now the car runs properly.