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View Full Version : HELP! KA-T starts and idles fine, but dies after rev. VIDEO!

Chugpuppy
03-21-2012, 08:07 PM
So, I finally got my turbo setup installed and now I'm in the troubleshooting phase. First off, specs:

Greddy TD06H-20G 8cm2 turbo (new internals/housings)
Greddy cast top mount manifold
Greddy front mount intercooler
Greddy intercooler piping
Greddy Type RS bov
Greddy adjustable fuel rail
Greddy FPR
Greddy downpipe
Enthalpy ECU (440cc, 20g, Z32, 93 oct)
RC Engineering 440cc injectors
Autometer Phantom boost gauge (0-30)
Z32 MAF with pigtail
Walbro 255 lph fuel pump

Now, the problem:
The car starts and idles fine. The problem is, when I rev it and let off the gas, the rpms fall right past idle and the engine stalls. When it does this it looks like it's running really rich, as grey smoke comes out of the dp after it dies. When I rev it up the BOV doesn't seem to be opening. Manifold vacuum is normal at idle.

https://www.youtube.com/watch?v=qgjBu1sOL2U

My theories:
Stuck BOV
Bad or miswired MAF
Boost leak? (pretty sure I don't have one, but can't rule it out.)
Electrical issue?

Help me out guys! I have to get it running and driving by sunday! I need ideas for troubleshooting so I can start Friday night. Thanks!
KiLLeR2001
03-21-2012, 08:21 PM
Whats fuel pressure at? AFR's? Even if the BOV is stuck you'll just get compressor surge. It almost seems MAF related. You'll want to make sure the white wire (signal) is free from interference. Pull out the multimeter and make sure you're getting correct readings. Black wires are ground, white wire is signal, black w/white is ignition on
Chugpuppy
03-21-2012, 08:29 PM
Whats fuel pressure at? AFR's? Even if the BOV is stuck you'll just get compressor surge. It almost seems MAF related. You'll want to make sure the white wire (signal) is free from interference. Pull out the multimeter and make sure you're getting correct readings. Black wires are ground, white wire is signal, black w/white is ignition on

Yeah the MAF was my first thought... Don't know fuel pressure atm :eek3d: Have my wideband waiting to be installed... Does anyone have a correct MAF wiring diagram for a z32 MAF to a S13 KA24DE harness? I've found conflicting reports. Pretty sure I have it right though.
StryfeS13
03-21-2012, 08:38 PM
Boost leak test it, it's really easy.

Get a plumbing end cap that will fit where your maf is, drill a hole in the end of it, and install a valve stem. Then using an air compressor, put some air into your system via the valve stem. Listen for leaks and get a spray bottle with soap to detect them.

By stuck BOV do you mean stuck open, or stuck closed? If you think it is stuck open, you should make a block off plate to test it. Really easy, cut some flat piece of metal out, drill two holes in it, bolt it in place of the bov.

A miswired MAF would cause it to run either super rich, or act like the maf isnt there at all (wont rev past 2.5K)

Let me get you an old diagram I drew, one sec.

EDIT: Here you go

http://i53.tinypic.com/20pvf4o.png
Chugpuppy
03-21-2012, 08:44 PM
Could it be that my MAF is too close to the turbo? I have it mounted directly on the turbo intake. Heard that could cause similar problems...

My MAF is wired exactly like that, so check that one off I guess...
StryfeS13
03-21-2012, 08:47 PM
Yes that could definitely be it. It needs to be further away, and you should curve the pipe if you can. I'm pretty certain that having the MAF they way you have it can ruin it....Unplug your maf and see if it dies still?

Just do this. (Mine, it worked fine when I was KA-T!)

http://i1099.photobucket.com/albums/g399/indobingo/turbo1.jpg
KiLLeR2001
03-21-2012, 09:26 PM
Yeah, (taking a second look at your setup) that MAF is way too close for comfort IMO.
Chugpuppy
03-21-2012, 09:27 PM
Yeah, I asked around and everyone pretty much agrees MAF turbulence is fuckin my shit up. Sigh. Knew it would be something stupidly simple. Would that cause it to die though?
StryfeS13
03-21-2012, 09:31 PM
I dont know..thats why I said unplug your maf and see if it dies still.