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DB2: Increase Case Pressure-Turn Up Fuel: Questions...........

deejaaa

deejaaa

Diesel Beginner
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i have done both per these instructions:

"Transfer pump: This increases case pressure. Looking at intake of pump inside inlet fitting, there's a 5/32 allen screw, turn clockwise looking at it, increasing case pressure and timing advance across board. Be careful, too much and it will blow seals out of shaft and pump fuel into engine.
Benefit is slightly improved throttle response and better fuel atomization.
One half turn will increase upper rpm and lower rpm housing pressure, timing will advance slightly."

and fuel increase procedure:
Increase Fuel
Take off small cover on drivers side of IP. It's very small and has 2 screws holding it on. Will need to remove throttle cable and bracket to see cover. Once cover is off, a little bit of fuel will spill into engine valley. Look for a small 5/16th Allen screw under cover that appears through small access hole. Screw rotates with engine so will need to have a large breaker bar on crank pulley nut to rotate engine while looking for screw to appear in access hole. A small flashlight and mirror helps to see this screw. It helps to have someone turn crank while watching for screw, but can do alone, but takes longer. It helps to remove throttle cable bracket and detach cable from IP. May also have to move linkage to get to access cover and fuel screw.

Once screw's in sight use 5/16th allen wrench to turn it. To increase fueling, turn clockwise. It helps to turn in small increments. Turning 1/6th of a turn ( imagine 12 O'clock to 2 O'clock) gave a good fuel rate to match increased airflow from K+N and Kascar resonator pipe. Could have gone 1/4 turn clockwise, but wanted to be conservative. It is important to increase airflow along with extra fuel or will just put out black smoke without extra power. Once screw has been turned put back together.
http://www.flashoffroad.com/Diesel/injectionpump/mechanicalpump.htm

question is: will this cause noise to come from the IP?
i've replaced all injectors with known good ones and the noise is still there. not as bad but i still hear it. don't want to cause damage. should i decrease Case Pressure just to be on the safe side?
 
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hmmmm.... well, guess i screwed up. seems for every step forward i take 2 back.
 
Increasing case pressure will advance timing, but you can retard the pump timing to compensate. Just understand that as you consume the range of advance that the advance solenoid can give you, cold starts may get harder because you no longer can get it achieved by the added pressure. Then again, when you are doing this you are ALWAYS adding more fuel so that will compensate alot.

Retarding the timing by adjusting the pump afterwards should calm down the engine clatter to normal.

But if you are clearly hearing the pump make more noise not the engine that i can not speak to.
 
@Will L. That sounds exactly like my wonked out pump. White smoke on startup yet have to keep the white smoke because advancing the pump to clear it up causes too much mid throttle advance. Too much for me means glow plug erosion and eating even Duraterms. Never-mind the clatter with hot precups under high load. Should not clatter under those conditions...

@deejaaa the housing pump pressure via the screw needs to be set at a pump shop - refer to the reference section's military repair manuals. IMO It's possible to get a gauge on it in the engine, but, accuracy and all is best at a shop. Note that the lift pump pressure also affects timing as the screw you are messing with for housing pressure is referenced off the inlet. So a restriction that is pulling a vacuum on the fuel line will be retarded vs. 5 PSI at the inlet of the IP.

Did the throttle cable bushing rubber fall out on the pump end? I get all kinds of noise without it transmitted through the pedal. Difficult part to track down it is w/o the entire cable.

I would crack injector lines until you know what cylinder has the noise. Only thing that could affect "A" cylinder and not all 8 from the IP is the delivery valve.

You tried ATF in the crankcase to free up a possible stuck lifter?

Noise at the pump itself would have me remove just the oil fill tube and check the bolts holding the IP drive gear on. 2 nuts and the oil fill tube pops out. Rotate engine with socket on alternator pulley to bring each of the 3 bolts into view and to get a socket on. You are doing it wrong if you are pulling the water pump. Wrong = hard way.
 
WarWagon said:
@Will L. That sounds exactly like my wonked out pump. White smoke on startup yet have to keep the white smoke because advancing the pump to clear it up causes too much mid throttle advance. Too much for me means glow plug erosion and eating even Duraterms. Never-mind the clatter with hot precups under high load. Should not clatter under those conditions...

@deejaaa the housing pump pressure via the screw needs to be set at a pump shop - refer to the reference section's military repair manuals. IMO It's possible to get a gauge on it in the engine, but, accuracy and all is best at a shop. Note that the lift pump pressure also affects timing as the screw you are messing with for housing pressure is referenced off the inlet. So a restriction that is pulling a vacuum on the fuel line will be retarded vs. 5 PSI at the inlet of the IP.

Did the throttle cable bushing rubber fall out on the pump end? I get all kinds of noise without it transmitted through the pedal. Difficult part to track down it is w/o the entire cable.
(as far as i know it's still there. not sure about rubber but i have a plastic piece that connects it to the bracket. is that what you mean?)
I would crack injector lines until you know what cylinder has the noise. Only thing that could affect "A" cylinder and not all 8 from the IP is the delivery valve.
(i've replaced all injectors already with known good ones. there is a noise but not as bad.)
You tried ATF in the crankcase to free up a possible stuck lifter?
(i used Marvel Mystery Oil and Rislone. didn't seem to make a difference.)
Noise at the pump itself would have me remove just the oil fill tube and check the bolts holding the IP drive gear on. 2 nuts and the oil fill tube pops out. Rotate engine with socket on alternator pulley to bring each of the 3 bolts into view and to get a socket on. You are doing it wrong if you are pulling the water pump. Wrong = hard way.
(that's the way i did it when i put in the new IP, the easy way. i will look at them again to see if there is something going on there.)
Click to expand...
in bold above..........
 
Will and WW, i made a rookie mistake. reading the diesel engine PDF, i discovered this:
"The injection pump drive shaft has a center bore that allows a spring-loaded plunger to contact a metal finger on the back side of the water pump plate (see Figure 7-20, view A).
Because the gears use teeth cut in a helical pattern, end-play causes changes in fuel injection timing. The springloaded plunger provides thrust force on the injection pump drive shaft to control the end-play of internal parts. It also keeps the timing between the drive and driven gears from changing as the result of driven gear endwise movement."
it's on page 7-23 of this PDF. it's recommended to download to view:
http://www.mediafire.com/download/h...015_12_1_1991_6_5L_V8_Turbo_Diesel_Engine.pdf
question is, can this be the cause of the noise by leaving it out?
 
:facepalm: You are pulling the water pump after all. I get to do things over now and then too. The forces the IP dishes out stretches double roller timing chains. Good time to put the gears in...

DO NOT "LOAD" THE ENGINE WITH MMO IN THE CRANKCASE!!! There is at least one documented case of MMO wiping the bearings clean out of an ATT turbo! IMO dump the crankcase oil contaminated with MMO ASAP!

The rubber bushing I talk about is where the throttle cable end goes over the linkage on the IP. My 1992 project has a different cable without it for some reason. Regardless when the rubber falls apart it gets noisy in the cab without weight on the throttle pedal from transmitted vibration.
 
I cant seem to open the download, but on my phone- laptops dont bounce apparently.

MMO- mystery marvel oil? If so- total crap -run away from it unless you are using it as a cutting oil. It is a cutting oil that helps INCREASE friction while cooling metal more than being dry.
 
  • Will L. said:
    MMO- mystery marvel oil? If so- total crap -run away from it unless you are using it as a cutting oil. It is a cutting oil that helps INCREASE friction while cooling metal more than being dry.
    Click to expand...
i know now....
sctrailrider said:
If you did leave that pin out you will need to put it in their, it's there for several reasons ...
Click to expand...
i know now. rookie mistake. hope no damage done...
WarWagon said:
Good time to put the gears in...

DO NOT "LOAD" THE ENGINE WITH MMO IN THE CRANKCASE!!! There is at least one documented case of MMO wiping the bearings clean out of an ATT turbo! IMO dump the crankcase oil contaminated with MMO ASAP!

The rubber bushing I talk about is where the throttle cable end goes over the linkage on the IP. My 1992 project has a different cable without it for some reason. Regardless when the rubber falls apart it gets noisy in the cab without weight on the throttle pedal from transmitted vibration.
Click to expand...
i am just pulling the oil fill. i'd love to put in gears but need a job before i could afford those. will have to look at the rubber you're talking about. doesn't ring any bells.
too late on the MMO. ran 5 miles on it already but will drain and fill with oil before i drive it again.
i have the pin in now.
just have the IP bolts in.
about to put IP lines back on but gonna confirm they are all in the correct order first.
saw a vid where the PO had put them in the wrong order so has me questioning myself.
 
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Will L. said:
5 miles, dont sweat it. It wont have had time to do anything.
Click to expand...

Depends on who is driving. :p Some things don't exactly last a 1/4 mile and I have a grand total of 4, four, miles on my project truck under it's own power. The cans of ether per mile is an amusing number...
 
there is definitely no rubber anywhere on the linkage so not sure what you're talking about.
removed the IP, installed the spring loaded POS plunger, cranked it up and it sounds like a whole different animal.
this is the piece:

that made me remove this:


and waste a whole day.
to top it off, after getting it all back together, i noticed i had left the IP feed line off and had to remove the intake again.
i'm tired.
tomorrow will be oil change and a test run.
 
I have been known to replace the IP feed line by laying on top of the engine, moving the FFM out of the way, and reaching under the intake from the rear. It's completely by feel with a small 1/4" socket and ratchet to get the worm clamp on.
 
You guys are frickin nuts leaving thr ffm on the engine. Move that sucker to the drivers fender well or firewall where it should have been from day 1. Thats my 2 farthings.
 
Jay, did you put the inner spring inside that spring? If not you'll have to take IP off again. Hope it didn't drop inside the oil pan.
 
Burning oil said:
Jay, did you put the inner spring inside that spring? If not you'll have to take IP off again. Hope it didn't drop inside the oil pan.
Click to expand...
as soon as you said that my heart dropped and my mind started to smoke and burn.
Burning oil said:
Just kidding ^
Click to expand...
and then it cooled off. what a jokester! thanks!
Will L. said:
You guys are frickin nuts leaving thr ffm on the engine. Move that sucker to the drivers fender well or firewall where it should have been from day 1. Thats my 2 farthings.
Click to expand...
mine has been on the pass fender for years(never mind i've not driven it for the last 4) and i also feel it should be moved. i've even ground down the mounting ears from the intake.
 
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