incendui

Heres my dyno charts from last weekend. I have
720 primaries, 550 secondaries, an SAFC, and a stock turbo which creeps to about 9psi.




The final run, with the lowest a/f ratios, had the SAFC set at +40% below 3800 and +50% after. The engine cut out at around 4700rpm, I'm guessing because the ecu realized the afm reading was way out of whack.

I'm thinking this means I have a fuel pressure problem...

jacobcartmill

iTrader: (6)

dude those numbers are not good... i'd get that fuel issue figured out, your engine hates life right now.

gsracer

Holy ****.

When was the last time your injectors were cleaned? You might have a clog in one or more which would result in you running lean.

Check the voltage at the fuel pump, and pick up a walbro fuel pump. You will probably want to do the fuel pump re wire.


You should be running RICH, something is very wrong.

incendui

I already have a walbro, and the reason the 720cc injectors are in the primary slots is because I thought maybe an injector was clogged. The first four runs on the a/f chart are with the 550s as primarys, for the later runs I swapped them because the 720s are brand new (and I hope shouldn't be clogged). But, I"m still way too lean under 3800rpm. All I can think of is that the pump needs to be rewired, or somehow the walbro died.

Now, is there any easy way to put in a fuel pressure gauge? I don't think theres any kind of test port for it.

Chimeron

Ummmm..... did it get leaner as you tuned the afc richer? If it did there is a way to switch it between AFM and MAF. This reverses the settings as I understand it. So try and figure out if that is what's happening. Not saying that's your only problem, but that is all I can help you with. :shrug:

incendui

It definitly got richer as I tuned it richer, it just wasn't rich enough. Even if I left the settings at zero though (which I tried originally), the car should be running very rich. Its not making much over stock boost levels, and has 720cc injectors in place of 550s.

This leads me to believe its the fuel pressure, since the ecu must be increasing the duty cycle proportional to the afm reading, otherwise the a/f reading in the last graph wouldn't be as constant as it is.

Wankel7

I made up this pressure tester for my fuel system. Cheap and it works

https://www.rx7club.com/showthread.p...ght=fuel+gauge

James