RB26 "crapping out"?

[T'Barb]

Okay, here's the problem. My R32 GT-R's engine will randomly sputter out and lose throttle, sometimes after some lead-footing, but usually for no discernible reason. The engine will sputter for a moment and then will become less and less responsive in the upper RPM ranges past 2-3K RPM until I finally get no throttle response after that, if that is I lose response while in those ranges. The engine will then bounce off the 2-3K range as if it were the engine cut point. The turbos will spool, but no boost will be built (0 PSI).

It's a mostly stock Skyline GT-R with the only mods being a 3" down-pipe and a Border-tuned ECU (with unknown properties). The engine troubles have been happening long before the ECU was swapped. Checked MAF, spark plugs and TPS: all were fine.

So quite plainly, WTF is wrong with my car?!

Greatly appreciate any help, thx.

[Eber]

Your Mafs are less than fine.

[DarkCaporaL]

^ +1 ^

Seems your car is going into limp mode, check your mafs. You might want to check your coils and plugs while your at it, doesn't take too long.

[T'Barb]

Seriously, MAF's are clean. Took them apart a few weeks ago and they looked new. If it were the MAF's, the problem would be constant as opposed to sporadic.

Will check again, though.

[Brendan]

I would put a large wager on it being some sort of MAF issue.

More than likely a bad connection/shitty wire... that would explain why it's intermittent.

[xcye]

Seriously, MAF's are clean. Took them apart a few weeks ago and they looked new. If it were the MAF's, the problem would be constant as opposed to sporadic.

Will check again, though.

Try a pair of known good ones. Their appearance means nothing! Also, problem with MAFs can be constant or sporadic.

[DarkCaporaL]

I would put a large wager on it being some sort of MAF issue.

More than likely a bad connection/shitty wire... that would explain why it's intermittent.

Brendan has a good point there. Maybe theres a short in your wire or connector, and when you hit a bump it short circuits.

[T'Barb]

Brendan has a good point there. Maybe theres a short in your wire or connector, and when you hit a bump it short circuits.

That would be extremely plausible! I shall take a look at the MAF wiring today.

EDIT: Jesus Christ! I need a wiring diagram

[ooter]

if you can get a hand on a scanner, hook it up and drive around, it'll tell you if the mafs arent working, or cut out for some reason. i use a snap on solus and put it in as a 300zx twin turbo, reads it perfectly.

[T'Barb]

I was messing around under the hood yesterday and I think I might have found the problem. There were two wires spliced into the daytime running lights, with one of them going to a ground in the frame. They were originally used for a lit license plate frame which I removed some time ago (did not fit North American license plates), but I never thought to remove the wiring for it.

So far so good. I'll report back if the car trips out again. Hopefully this was a very easy fix for a very troublesome problem ops:

Fingers crossed!

[DarkCaporaL]

These cars are always a wiring mess lol.

Hope it fixed it. :-)

[T'Barb]

These cars are always a wiring mess lol.

Hope it fixed it. :-)

While I was driving it today, had a VERY BRIEF relapse (like a couple of seconds), and then suddenly it reverted back to normal. Goddamn Skylines! Hopefully this was a one off.

[T'Barb]

FOUND IT!

Was driving it today and it had the same problem. Turns out there was a bad connection RIGHT IN THE MAF PLUG!

Chop. Splice. FIXED! Hurray!