1989 12 valve non intercooled with a hx35, it made only 8 psi of boost at wot so I turned the power screw one turn and adjusted smoke screw and star wheel all the way down and it didn't change anything and still no black smoke, I assume this was a fuel supply issue so I replaced the fuel filter, still no difference, tested fuel pressure and was at 5 psi at idle and didn't go up when just revving in park. anyone know the solution?

 

Have you checked for boost leaks?
Made sure the fuel pin is not stuck and moves up and down freely?
Is that HX35 in decent shape?

 

Check to see if the waste gate isn't stuck open. Also check the little tube that goes from the intake to the injection pump. Either one of those can be the cause.

 

i have pretty much ruled out boost leaks because it would have some black smoke but there is none

 

i checked the fuel pin and slide pin and they moved freely, hx35 has no in and out play and just a tiny bit of side to side play

 

Not sure how to check the out put of the IP. It may be dying.

 

can the ip output decrease without any other symptoms because it idles fine and revs up without any hiccups

 

Is it hard to start?

Mine takes a very long time to get up to speed. It will die at a traffic light, and other inconvenient times. I have an electric pump in the tank too. My FSS has been gutted. Tese things are supposed to push @8000psi to the injectors.

 

I have no idea what I'm doing. I have the THD pin, and the 3200 spring. It was having problems before I swapped them out.

Reading on another site 250K it might be time for rebuilding the injectors, or swapping in new ones. Evidently the nozzles are a wear item. I have a set of rebuilt 50+HP injectors from DAP. Haven't installed them yet.

No leaks on my IP.

 

Have you tried to turn the fuel screw in until the idle hangs (close to runaway) and then back it off a turn and adjust the idle to where it needs to be?