BearKiller

The Cummins nut around here made an adjustment on my injection pump to smooth the idle and up the fuel.

I couldn't see just what he was doing; but, he removed a long thimble looking cap and handed me a washer, saying not to lose it in case we ever wanted to replace it.

So I can learn more about my truck, what does it sound like he did??

Whatever he did, the truck sure idles much better and about a hundred RPM faster.

Chrisreyn

Bear, I copied this from the TECH FACTS section.. souns liek what the guy was working with on your truck..BTW the colored font is realy hard to read....

Full Power Adjustment
Unless your AFC or Diapraghm is way out of its proper setting. This is all you should have to adjust.
On the rear of the pump, partially concealed by the fuel lines, and under a plastic cap is an other adjustment screw. Remove the plastic cap, remove the metal collar tack-welded to the screw, loosen the jam-nut, and turn the power adjustment screw clockwise about 1 to 2 turns. After turning the Full Power Adjustment, you may need to re-adjust the Smoke Adjustment Screw to reduce low speed smoke, and the idle screw or throttle linkage to correct the idle speed.

If your smoke is only at full throttle load - back off the full load screw.
If your smoke is at low end thru pull-up - Back off the smoke adjust screw on the top of the diaphragm housing. If you have dramatically adjusted the "star wheel" (the cogged adjusting wheel under the diaphragm) it can have the same effect, as even very slight boost will cause it to move to "full fuel", instead of waiting for the turbo to spool up a bit. Adjust the star wheel back a bit to reduce the smoke level.
If smoke is heavy at immediate start-up - fine adjust the smoke setscrew.

wannadiesel

Jeez, I guess I oughta back everything off.

timb

Ya right Dave.that'l never happen.

NoSparkplugs

Dave remember, smoke means your making power . And power is a good thing.

frostie

smoke is always fun....
the screw on top, they call it the smoke screw. Dont touch it, unless you want smoke only, and no power.
In the facts section you can learn to turn up the fuel.
there is a fuel screw. look in the tech section.
screw that in 1 turn at a time and you wil see good power results.
I hope you have a pyrometer. if not we will talk to you tommorow.

BearKiller

Yes, I do have a pyrometer.

I am unfamiliar with the pump-turn-up lingo.

By removing the pressed on cap and taking out the little washer, what modification was actually performed??

Is there a step by step tech article on the various modifications and results of modifications that I could refer to??

I would like to see a progressive, climb-the-ladder, list of power gaining recommendations that can be done without getting radical or decreasing the dependability of my engine.

wannadiesel

He turned up the main fuel screw.

The article in the FAQ was borrowed from http://dodgeram.org/tech/dsl/more_power/Power_ve.htm which is probably one of the better step-by-step pages out there. Don't take everything in it as gospel, but it's a good guide for a newbie.

Until you grind the AFC lever you haven't gotten into "radical" territory. Everything else can be undone the same way it was done.

I have forgotten what year your motor is, if it was out of a non-intercooled truck, swap turbine housings, throw in a 3200 RPM spring, and turn the pump up until you're happy. If it was an intercooled motor, you might want to consider injectors in addition to all that.

You'll probably wind up with POD's and a severe EGT problem within a year.

ChrisLib

Thank you Dr. Dave , but you forgot to tell him to take two tablespoons of Power Service and call you in the morning

wannadiesel

We cannot cure this disease, we can only treat it.

BearKiller

Engine is a non-intercooled 1989 model.

Note the truck.

I really appreciate all the help I get here.

This is probably the most helpful, good-natured forum-site that I belong to.

wannadiesel

Yep, I noticed that it was in a Ford - which is why I didn't know whether it was an original intercooled motor or not.

That '89 motor will run pretty hard with just some pump tweaks - right Greg?

Have fun sliding down the slippery slope with the rest of us.

G1625S

''That '89 motor will run pretty hard with just some pump tweaks - right Greg?''

not too bad for an old chunk o' cast iron

BearKiller

Right now, it feels like a hard-mouthed horse trying to take the bits and run through the bridle.

wannadiesel

Just wait until we badger you into putting in the 3200 RPM governor spring.

Sorry, Greg - it had to be done!