bakerroc

Hi all. Frustrating story here. I've owned my '93 Dodge D250 for only a few months. It has 143000 miles on it. About 2-3 weeks after I brought it home it began to smoke. It has gotten so bad that people cross the street at intersections to get away from my cloud. It is blue/white smoke. The truck burns no engine oil. It has now begun to stumble on acceleration and idles poorly when cold.

I changed the lift pump with one I bought from Autozone a week ago for $50 just to be sure there was no problem there. This week I dropped it off with the dealer for diagnosis. They called and said the fuel transfer pump was not working. I explained it was new from Autozone and they rolled their eyes and said it was no good and it would cost $450 to replace. I said I would think about it. Questions:

1. How to test my lift pump.
2. Is is likely it is bad, ie does Autozone sell junk for lift pumps.
3. I considered installing a fuel pressure gauge but Genos literature says they do not work to diagnose problems with the fuel pump only to monitor pressure. Why won't a fuel pressure gauge tell me anything about pump health?
4. Is there a wrong way to install a lift pump? I mean, can the pump lever miss the cam lobe on install?
5. Where is all the darn smoke coming from?

thanks for as much insight as you can muster.
Rocky
'93 Dodge D250 Cummins ....

edwinsmith

White smoke means you have too much fuel. My guess is that your aneroid compensator is stuck in the down position. Possibly the spring is broken. If it was cold I'd say you had a KSB problem.

To test the lift pump, there is a bleeder screw in the middle of the banjo coming out of the top of the fuel filter. Take that out and work the lever on the pump or crank the engine. If you get a good stream your lift pump is good. If you don't lose prime the truck can still run good with a bad lift pump. The pump runs on an eccentric on the camshaft. If the engine stops in the wrong place working the manual lever won't work which is why I suggest cranking the engine. You can pull the wire off the fuel solenoid if you don't want it to start. I seriously doubt you have a lift pump problem.

Edwin

timb

Kind of wonder if there is a boost leak somewhere.

Boatnik

Me too.
I mounted a fuel pressure gauge some time ago and I cannot understand why anyone would say that you cannot use it as a diagnostic tool. I drilled and tapped the banjo bolt that had the vent plug to 1/8 pipe. I installed an isolation vale there and throttle the valve down to eliminate pulses. It works great. It can even tell you when you need to change your fuel filter.

BearKiller

I would not do business there, anymore.

A missing lift-pump should not cause any difference in smoke, especially an increase.

Check Edwin's theory.

Raspy

Blueish smoke and stumbling can be a clogged fuel filter. You did not mention the filter. Did you change it too?

White smoke at startup is not too much fuel, it's a cold engine and condensation. Too much fuel is black smoke under load. Black smoke at idle is poor atomization (bad injector).

An extreme amount of white smoke might be water. Is it using any water?


John

jdwest

Did the injection pump timing slip? Mine was doing the same thing when I bought it. I bumped up the timing a little and all is well.

brainfade

Might want to check for air in the fuel as well. That will give a rough idle with smoke. Temporarily plumb in a section of clear hose ahead of the lift pump and look for bubbles. A cracked or rusted line will often leak air into the system but not leak fuel out.

Blue white smoke does sound like timing though.

wannadiesel

I'm with Brainfade and Wetspirit. Replace the filter and check for air leaks. And don't go back to that dealer.

bakerroc

Not using any water. Fuel filter changed 500 miles ago.
I am new to the whole diesel routine. What is an aneroid compensator?
The pump timing mark is below the white line. Is this advanced or retarded? (I need a good manual! )

thanks for all the help here.

Rocky

jdwest

The timing on mine was below the white line as well when I got it, making it retarded. In reading "the sticky" at the top of the page, it was suggested to bump the timing 1/8" above that line. That was all it took to make the smoking, nasty running symptoms a thing of the past.

Raspy

The aneroid compensator controls the amount of fuel delivered. It runs on boost. So, the more the boost the more the fuel delivered. The throttle pedal only controls the fuel up to a certain point. It's a way to keep the smoke down by not overfueling till the turbo can spool up.

Just for the fun of it, change your fuel filter again. Then you can rule that out for sure.

John

Palerider

Sounds like injector pump problems, does it run alright once its warmed up or still white/blue smoke and stumbling? If its the same, IP.

JimmieD

Just a suggestion: if the injection pump has ever been rebuilt then the indexing mark on the block may not be the correct normal position for that pump. Rather than turning pump to the line, plus adding an 1/8 it's probably better to turn it an 1/8 from wherever it is and test drive. You can always dial more in later, but you may not need it now.

bakerroc

Palerider, it is the same warm and cold.
JimmieD, to my knowledge the injection pump was never worked on.

To Do:
Simple things:
1. change fuel filter again
2. pump the lift pump an see if it actually works.
3. check for cracks in fuel line and air in fuel.
4. Replace the banjo bolt with a tapped one and install a fuel pressure gauge so I know what the pump is doing.
5. Buy a shop manual.

Things I have not done before:
1. Advance the timing on the injection pump. Anyone want to give me a simple step by step?

Things I have no clue on:
1. Where is the aneroid compensator and how do I check it.

thanks again.

Rocky