N3philum

iTrader: (16)

I don't know where to begin with this issue but.... Anyway..

mods
35r
vmount
550 primary 1680 secondary
HKS twin power
Power FC with a previously good tune (the car has been down for a while but this was an issue the last time I drove it about 8 months ago)

I can cruise around no problem. Idle is real smooth. As soon as my car see's a load pushing it past atmospheric pressure, it starts to sputter and run real shitty. Yesterday, I did't try too hard to get it to push past the stuttering. Today, I kept pushing it and it seems like it boosts to 15ish psi and then hits a boost cut.. External waste gate doesn't open at all. It runs real bad and has no power. Additionally, it used to idle at 12.5 afr. Now, it is idling at 13.5. Also, under load, the AFR sits between 14.8 and 15.3.

Things I checked.

Map Sensor (swapped with known good)
Injectors (checked to make sure they are firing)
New spark plugs installed
Checked leading and trailing coils, all within factory spec.
Plug wires are good
Fuel Pressure is at 36psi at idle

I want to say it is a fuel delivery issue...I think I may have; a clogged filter, fuel pump is dying, clogged injectors or the pressure regulator is crapped out... But, I really don't know.

I searched but I don't know where to start.. It doesn't seem like anyone has found or posted a solution in the threads I did find.

Any help would be great.

zeroG

iTrader: (28)

You're never going to find a simple "solution" for any problem you have. You need to test and try things and see which one works for you.

How did you check to make sure your injectors are firing?

If it's the injectors they could be either sticking open, or staying closed. And it would probably be the secondarys. You can try finding some spare 850's and replacing them, they're not very expensive.

Fuel filter could be the problem, but I don't think so if it's only sputtering under boost. Regardless if you've never replaced it, now would be the time.

Your fuel pump can also not be supplying enough fuel pressure under boost if it's dying, that's easy to check though, there's plenty of threads you can find on how to check the fuel pump and the proper voltage it should be getting.

N3philum

iTrader: (16)

Checked the injectors by touching a lead from the batt to each post on the injectors. all 4 injectors click open and closed. They could be clogged... but. The car has sat for a while, but I experienced this problem just before the last time I drove it when the injectors where new so.. I really don't think they are a problem. I am working on doing a vacuum test to make sure it isn't an air issue but that wouldn't make much sense if the car is starving for air and going lean on the wideband.

zeroG

iTrader: (28)

So you have a wideband and it's showing lean?

Did you check the resistance between the injectors pins?

You can also check the injector plugs coming from the computer to make sure they're getting voltage.

N3philum

iTrader: (16)

Yeah, wideband is showing 14.8-15.xx when under load. Before it was idling at 12.5 and now it leaned out to 13.5. Secondaries are controlled by an FJO injector driver. I'm not sure what voltages they should be getting, but it seems to be okay. I didn't check the resistance between the pins.