1997 12v loss of power
 

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 pump 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 power . 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 fuel 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 high pressure pump 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 injector pump and see if the rack moves.. just a thought

sounds like your afc foot isn't moving have you checked the boost line going from the head to the afc housing?

yes i have checked the line and it looks good... was thinking about manually presurizing the line to see if i can see anything move... thanks

Take the AFC housing off and bench test it with air. See how many psi it takes to move it full forward.

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planning on testing the AFC with pressure. then checking the rack by turning on the key and moving the throttle linkage with the plate removed....

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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.

At that point I would just recheck timing. Its possible its slipped.

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I just rechecked timing and used the pump pin. I am currently set at about 17 degrees it was a little lower a few weeks ago and I bumped it up... I also ran the truck with the afc foot off no difference no smoke seams to run good to about 15 lb of boost then real flat and it never smoked at all. weak. I had heard that the fuel shutoffs can be a problem I did turn on the key lift the shutoff arm had afc off and moved linkage. it moved forward to the plat so it looked good.

Take the solenoid off the shutoff and flip it forward by hand and try it again

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PUMP IS AT THE LOCAL SHOP ... THEY ARE TESTING THE PUMP FOR ME.. THEY MENTIONED I SHOULD HAVE TOOK THE SHUOFF VALVE OFF AND RAN IT THAT WAY BUT ITS OFF NOW GETTING CHECKED OUT. I ALSO JUST WENT THROUGH THE DROP VALVE METHOD OF CHECKING TDC IT WAS VERY CLOSE TO WHAT I HAD BEEN USING.