Thread: trouble shooting ideas?

ive had my nx boosted for about 2 months or so now.....probably put 5000 miles on the setup. nothing crazy.....as i havent tuned it and i just putt around, its just running on the stock ecu. ghetto, but WHATEVER. just today, i was going out of town, and made it 30 minutes into my trip and car seemed to go into limp mode/boost leak mode. while ive had half a dozen boosted b13s.....and i can usually get them right pretty quick, this ones messing with my mind. when i got home (barely) it was missing really bad around town. But on the highway, if i kept it around 3000 rpm it had a decent ability to stay cruising.....even though it was at 55 miles on hour. plugs are BLACK. so i figured it was a boost leak. while i found a few tiny ones, there wasnt anything major, AND the problem persisits. just breaks up.....falls on its face.....barely can back it out the driveway. it seems to have developed the urge to stall if reved up. also, this problem is load based. it IDLES perfect. m wondering if the fuel pump locked up or something. any suggestions?

i dont SEE anything odd. maf wires are fine, all sensors plugged in.

First off running on stock ecu is just making it harder for you to fix this problem try another maf and if that doesn't work check cell codes do you have a after market fuel pump? Is your battery relocated?

Is the car missing on any particular cylinder. I'd start pulling some plug wires and find out exactly where the miss is. If it's missing across all four then I would suspect a fuel or ecu related problem.

i guess i should try to be clearer. car is bone stock, other than the manifold, turbo, and intercooler. i dont really see how a maf based ecu would care weather or not there was a turbo on the car. only thing different is timing maps, mafs, and injectors. ANYWAYS. i cant say if its missing on cylinders....like i said its load based. id have to be under the hood while the car was being driven down the road. it idles perfect. stable vacume. its weird. id say bad fuel pump/clogged fuel filter.....but why would it run RICH? thats whats throwing me off. i tried pulling plugs wires for shits and giggles.....nothing interesting happened. its strange that i could put so many miles on it, and then this. i have to assume its the fuel pump.....as i dont "boost" it theres really nothing other than stock failure points that i can think of. mafs dont fail just driving around....hell i havent even seen a fuel pump do that. hmmmm.....i have a wlabro i can throw in.....probably make it run a bit rich, but if the funky load based miss/break up goes away, i guess thats the problem. ill check the fuel filter too.

blow through or draw through?

draw through. which is why i suspected boost leaks. BUT i did a leak down test. other than a cracked line on the wastegate, i could find nothing. im going to try putting the maf on the throttle body tomorrow. if THAT doesnt change something, than im lost. lol. seems like something small and simple. it usually is. but i cant think of anything right now.

I had the same problem a long time ago. Bad ecu. It wouldn't boot up properly, and basically the engine ran (barely) without reference from any sensors. Swapped the ecu out, and it ran flawlessly.

hmmm....that is always a possibility.

Check your cap and rotor....mine did this too...would idle fine....under load it would stumble and sometimes die if i got out of it....cap was melted where the contacts are....replaced it and good to go....gotta at least check it