3.5 DR750 build

[JasonY]

Pressure still stuck high. Anything we're missing other than the obvious fuel return line limit? Might buy some bigger line to run off the afpr and bypass the stock return just for diagnostic purposes.

Jason

[TurboSinceBirth]

Which AFPR are you using and are you sure there isn't too small of an orfice installed in it?

[anyonebutme]

return line plugged?

run a line into a fuel can from the return port......does it drop back down?

[Tigchamp]

The usual fix is to run a bigger feed and then use the old feed as a return. or alternatively if you are thinking of doing the rear steer delete use the lines from the front to the rear rack they are quite large bore and steel

[JasonY]

Got the pressure sorted out. Had the smallest orifice in the regulator, put in the big one, 45psi base now.

Still knocks at 5k-5500 like a fukin whore. Arc is maxed out. Need my compressor from work, boost leak suspected. If not, bonfire.

Jason

[wingnut]

...boost leak suspected. If not, bonfire.

lol...saved for future use

[SnakeSkinner]

Got the pressure sorted out. Had the smallest orifice in the regulator, put in the big one, 45psi base now.

Still knocks at 5k-5500 like a fukin whore. Arc is maxed out. Need my compressor from work, boost leak suspected. If not, bonfire.

Jason

Is the fuel pressure correctly matching 1 to 1 with boost? IE 45psi base, 55psi at 10 psi of boost, 60psi at 15psi of boost ect?


When you say ARC-2 is "maxed out" what do you mean?

[JasonY]

Yes, working 1:1 now. Cant find a balance between high/low. We have the high maxed out and not enough fuel up top, still leans out in the middle since to keep the idle at all, needs the low fairly lean, around zero or +1, accel at +3 i think and its not enough down low causing it to come up short up top. Cant seem to get it balanced to where it will idle, fuel enough down low but have enough fuel up top. We got a few clean pulls, but had so much fuel it wouldnt idle, at all. And was like 10:1 up top, probably looked like a diesel lol.

Fixed all suspected leaks and will reassess tomorrow after any/all leaks fixed.

Last time we had this problem with the ARC is was a leak. So we shall see. But even at 14psi it'll pull smooth/clean to 5k rpms nice flat AFR 11:1-3 and around 5k...gotta lift since it'll instantly/predictably jump into the teens on knock.

Jason

[futurevr4man]

i know there is a flashable sittin in the basement. just sayin...

i dont get the bonfire reference?

[Greg E]

Yes, working 1:1 now. Cant find a balance between high/low. We have the high maxed out and not enough fuel up top, still leans out in the middle since to keep the idle at all, needs the low fairly lean, around zero or +1, accel at +3 i think and its not enough down low causing it to come up short up top. Cant seem to get it balanced to where it will idle, fuel enough down low but have enough fuel up top. We got a few clean pulls, but had so much fuel it wouldnt idle, at all. And was like 10:1 up top, probably looked like a diesel lol.

Fixed all suspected leaks and will reassess tomorrow after any/all leaks fixed.

Last time we had this problem with the ARC is was a leak. So we shall see. But even at 14psi it'll pull smooth/clean to 5k rpms nice flat AFR 11:1-3 and around 5k...gotta lift since it'll instantly/predictably jump into the teens on knock.

Jason

Pump gas sucks.

Install the 98 ECU and set the injector scalings. Get a decent tune with the ARC. Tweak the timing with ECUFlash.