P0300 Random misfire supercharged

[stuperdave]

Hello all,
Some what new to Nissan. I bought an Xterra a couple years ago which I love just wish I would have checked it a better before...
The issue now and reason for the post is a friends '04 350z with a Stillen supercharger with about 35,000 miles on it. They had someone else replace the belts unfortunately after an idler pulley locked up and the belts broke. It was one driving the supercharger I believe. It ran OK for maybe 10 miles after it had been repaired but started running rough, so rough it will not idle. The codes I am getting are
P0113- Intake air temp. sensor 1 circuit high input
P0102 - Mass air flow circuit low input
p0300 - Random misfire
I changed the mass airflow sensor (with a salvage yard part, I know but they are "budget constrained") which helped some but it just won't rev up. Any thoughts/suggestions? Not sure but I believe it to be a Stage 2 maybe 3 supercharger. I talked to "someone" at Stillen once that indicated that the broken belt may have messed up the supercharger but he said that wasn't really his area and since have not had much success in talking to anyone there.

[PapaSmurf2k3]

Budget constrained and forced induction usually don't go together ha.

Yeah, I would first say look for vacuum leaks, or loose/cracked couplers after the MAF.
Did the belt flail around and wack into any wiring/connectors when it broke?

[evildky]

Maybe start by replacing the bad IAT? Have you changed the plugs?

[stuperdave]

Thank you for the suggestions, I will give those a shot. LOL Papa, those two are generally exclusive but this is a long story And evildky, is that your race car? I have a friend with a '78 280z that he used to race a little in SCCA events. We never really could keep from boiling the brakes but that would be another thread

[evildky]

Yes my avatar is my car, although it's in pieces and has been for a few years. Popped the junkyard motor, decided to do a full on balanced blueprinted longrod 2.9 build, then decided to fix the rust before putting it back together, and kept finding more rust and just ran out of talent. One day I'll have it back together. It has 12.2 vented villwoods all around brake boil isn't an issue. So for now I run the 350z.

[stuperdave]

So I replaced the Mas air flow sensor with another one from the salvage yard with no change. Changed the plugs which made a big difference for a few moments. Plugs were very black and the new ones are almost as black after only two or three minutes run time. It is just dumping way too much fuel in or maybe not getting in enough air (since it is supercharged I assume that would have to be that the throttle body butterfly isn't opening). It just has way too many issues for a vehicle with 23k on it.

[PapaSmurf2k3]

Does it have larger injectors and a tuned ECU? Almost sounds like the ecu lost its tune and is dumping way too much fuel.
Try giving it some vacuum leaks or other form of air intake without the MAF reading it.