leaning out at WOT

[turbo90]

Hey, I've had my 90 KAE turbo'd for a few months, and have finally ironed out most of the problems. One biggie I'm still having is that the A/F ratio leans out to about 12.5-13 when I give it full throttle. It runs in the 11's and low 12's at part throttle, on boost. Stock MAFS, stock injectors, 8:1 FMU, and a Walbro fuel pump. It's only at 3PSI max, because I can't give it full throttle. I'm thinking bad FMU, or a bad boost signal to the FMU. Any other ideas?thanks,TB

[fiznat]

Around how many psi are you leaning out at?

I would do a couple things. First, get an in-line gauge so you can monitor fuel pressure. You should be able to see if it is a pump or FMU problem right there. Beyond that, assuming you are boosting a decent amount, I would think the injectors could be your problem. It really sounds like a pressure problem to me though. Doublecheck the vaccum lines, and get that gauge in there to see whats really going on.

[nissanfanatic]

I had the same problem with my FMU setup. http://www.ka-t.org/tech Look into the fuel pump wiring modification. I did this mod and now I run right at 12:1. Good luck.

[turbo90]

I can only pull about 3 PSI (spike) because it leans out, I can't floor it. I'm gonna try to reroute the vac lines today, maybe that will fix it; if not, I'll try the relay for the pump.thanks for the info.TBPS, any KATers in Gainesville, Fl? I'd love talk sh*t/smoke a few stangs some night. aim = tomsbeetle

[Structure240sx]

where do you have your vac line for the fmu hooked up now? the injectors with that fmu should be good to about 9psi with most turbos people run.

fuel pump, fmu or FPR is most likely the problem

[:: orion ::]

PS, any KATers in Gainesville, Fl? I'd love talk sh*t/smoke a few stangs some night...

Plenty.

I started the G'ville 240SX craze back in '98 (turbo'd it in '03)...and a number of guys have recently done KA-Ts...most recent one went 12.9 @ 110 last week at Gainesville Raceway.

There is a local club, International Motorsports...they meet every Thurs @ 10pm, currently outside Godfather Pizza on 13th.

Stop by, tell them Brian sent you. I'm living outside JAX right now, but I still make it down for meetings occasionally. Most the guys are into road racing, auto-x, and rally...and there are a number of VERY knowledgeable Nissan guys.

http://www.intmo.com , check out the forums.

- Brian

[:: orion ::]

And to answer your question...fuel pump mod...run a new relay to insure the pump has a constant 12V...the old wires in your '90 can't support the current load.

Do that 1st...if you still have a problem, come back and let us know.

- Brian

[nissanfanatic]

I'm about 20min outside of G-ville. But I go in there often. Usually to scavenge the U-pull junkyard.lol But sometimes just to drive around.

[turbo90]

well, I re-ran some vac lines and that fixed the problem. I'll do the hot-wire setup in a few weeks when I move the battery to the trunk. So that's who's been over there, I work at the Pizza Hut across the street. I think the cops have been giving them a bunch of static lately, about three weeks ago there were about four with their lights on giving tickets, harassing, whatever they do. Now they just hang out down the street speed trap style.thanks for the help!!TB