blaster_works

First thanks for any help that can be provided.

This is a 1997 12v recently I had the KDP syndrom and changed my timing case. I took several days and it didn't seam like much of a problem. During this repair I marked the gear to shaft position and checked the timing prior to pulling the pump. the timing was at 14 degrees.

ok after reassembly I testy drive the truck and it sounds good but I quickly realize I am low on I watch the boost gauge and maybe it goes to 15 . no black smoke none no white smoke. so I double check the pump timing and it looks very close but I advance it a little .. I am using the timing pin buy the way... also my marks I put on the gear and shaft.. this might have helped a little but no real change. so I read and read. I read about the overflow valve and pressure, I had to take this valve off so it needed checked sure enough fuel pressure was only about 12. so I put in a larry b valve and the pressure came up to the 25 - 30 range, so I drive it no difference.

what gets me is that there is no black smoke this is the big pump the star wheel is loose and the plate assembly is all the way forward. there should be smoke. to me its like its not fueling.. I did look at the hose to the turbo and tried to move the dump by hand a couldn't not sure how stiff they are., I also pulled the line going to the turbo while reving engine and there was little to no boost pressure,

I am starting to think my is weak. thoughts tests ???

things on my list to check

X double check valve clearances
X could the cam gear have slipped on the cam with the KDP ???
x double check waste gate isn't stuck open
X put air pressure on the and see if the rack moves.. just a thought

blaster_works

no feedback yet ??

Tate

Are you getting boost when driving? A big boost leak can cause low/no fueling issue as it won't move the AFC foot. You won't feel much air coming out of the lines just free revving the engine. If you took the intake pipe off, you'd feel air moving then, but not the signal lines.

The wastegate has a lot of preload, tough to move by hand. A ruptured diaphragm will cause a boost leak, enough to keep the AFC from moving. I'd remove the signal line to the wastegate, since you'd need a fair bit of fuel to push the HX35 into the scatter zone.

Cam can't slip on the gear as it is keyed. It would have wear the keyway, or shear the key to slip on it, which is extremely rare. This wouldn't affect lack of fueling, but would account for loss of power.


Check your AFC, make sure the diaphragm isn't rutpured. Check the wastegate diaphragm as well. Make sure the signal line from the head to the AFC is intact and clear, and no leaks. You can remove the AFC foot from the housing and go for a drive. If your lack of fuel goes away, then you can limit your search to faulty AFC, leaks or open wastegate. If it continues, you'd be looking at pump issues, or a simple out of adjustment throttle linkage.

blaster_works

First just the input i needed thank you...


To answer your question i do get boost with the truck. it seams fine at low boost levels. Up to about 10 psi. just going down the freeway it will run at about 5 go up a hill and it moves to 10 looks normal but if i mash it it only goes to 15 ever... and its like there is nothing there. it used to shoot off like a rocket.. had this truck 15 years... just not right..... i think your thoughts around the afc sound on the mark.. i think i have the star wheel so loose that it can fuel easily at the lower boost levels... now i have noticed i used to smoke bad pulling away from lights if i lugged it. dont see that anymore either...

now for the waste gate i put about 35 psi on it and it didnt move. i think it is stuck closed will try a little more presure..

so you comented you can run with the afc off for a limited time. sounds like a good test do you get much of an oil leak.... i havent checked my lthrottle linkage but i will it just doesnt seam like the problem. i am also starting to believe this problem was there before the kdp i just dont haul very often and hadnt noticed it.

thanks will check it tonight.

infidel

Be careful going any higher, doesn't take much over 35 psi to blow out the wastegate actuator diaphragm.
More than likely if the gate is stuck it's stuck closed.

Tate

A wastegate stuck closed isn't going to hurt low boost performance. If anything, it'll make more power higher up by allowing it to move more air.

Don't drive with the AFC housing off. Remove the housing, take the bolt and pin out of the front. The foot will drop out. Put the bolt and pin back in, reinstall the AFC. Its known as gutting the AFC.

blaster_works

Well I checked the afc diaphragm about 30 psi to fully open . no leaks diaphragm looks good. drove with out the afc no real improvement gets there faster but still maxes out quick. AND no blue smoke, grrrrr

Also the waste gate diaphragm seams fine , holds pressure.
monitored fuel pressure out of the filter at about 30 psi.


I did look down at the end of the plate with the afc off.. when I move the linkage a piece of metal moves toward the plate then at about 1/2 throttle it starts moving the other way.... hmmm

oh yes the throttle linkage is fine goes to about 99.5 %


please other thoughts...... Now when I had the KDP I did retime but I put marks on everything. Bought a kit for measuring the lift on the pump looked up my pump for the right numbers because its a 215 and they are different.. but even if it was off there should be a lot of fuel going in this motor.

infidel

If you do the same with the shutdown solenoid pulled up into the run position the arm will contact the plate.
Make sure the arm isn't going under the plate.

blaster_works

I thought the shutdown sol would effect this so I turned on the key. this should have put power on the solenoid correct... I did not notice a difference..
you said make sure its not going under the plate???

Talked to a pump shop today they were recommending that I go back into the timing one more time and check the pin on the pump. shouldn't take that much time. I didn't use the pump pin when I set it up. just the dial indicator.. The only other thing that I have thought about is true TDC I used an aftermarket gear case so I am wondering how true the cam timing hole is.... but even out of time I would expect fuel and smoke.

infidel

The shutdown solenoid has two sets of coils.
The stronger one that pulls the solenoid up is only energized when the starter is cranking.
Just turning the key to run only energizes the coil that holds the solenoid up.
You need to help lift it with the key on.

blaster_works

thank you

I will take a look at that tomorrow.. what should I see going on under the afc with the key on and the shutdown lifted up ??

infidel

Give it some throttle till the arm contacts the plate.
Make sure the arm is contacting the lower part of the plate that sticks out the most. Like the tip of a nose.

blaster_works

well I checked that and yes the arm moves forward and hits the plate only at the very end does it retreat a little.. so I also when back and checked the pin timing on the pump... based on pin timing on the pump and just using the cam pin it looks like I am set around 17 degrees. I had advanced it a little a couple of weeks ago... so right now my plan is to take the pump in to be rebuilt. this truck used to be able to lay down some smoke.. even just off idle.. in my opinion just not getting enough fuel. I did put the pressure guage on my fuel filter output but it is a mech guage that I cant watch while driving. now mashing it it goes up to the 35 lb range just don't see that being the problem. I live in Waco texas and there is a good pump shop here but I want to make sure they know what they are doing.. one of there experts told me he doubted if it was the pump but what else could it be..

oldblues

partialy cloged fuel filter???

oliver foster

At WOT, AND driving under load, your fuel pressure could be MUCH less.
I would check that before rebuilding the injection pump.
I used a mechanical gauge for diagnosis.
I tucked the gauge under my wiper blade and closed the hood, this way I could still see the temporary gauge when it acted up when driving.