Adjusted Pump - Wow!

[JFitzgerald]

This past weekend, I got a chance to adjust my pump. BIG IMPROVEMENT! This is exactly what I hoped for, but in the back of my mind I didn't think it would improve that much. And I haven't switched the turbo housing yet.



I used the instructions from TST's web site. They made it simple. Access to the power and idle screws is the worst part. It appears that someone may have played with the smoke screw before, since the cap had a hole punched in it from prying it out. When I went 2 turns in, there was not enough thread left sticking out to put the lock nut on. Is it in too far now? I backed it off 1/2 turn later to experiment. The previous owner said the injectors were replaced at 60-some thousand miles, maybe they adjusted the smoke at that time?



My main question is this: Right after adjusting the pump, I took a test drive. There was a little bit more power at low end, but nothing after that, and just a light gray smoke at full throttle. I was disappointed and thinking I had one of the "very few" trucks with the injectors that won't flow more fuel, like the instructions mentioned. I took a 20 mile ride to a friends' place, was there maybe an hour, and when I left there, it started making a difference all the sudden. Pulls much harder through the gears, and smoke is heavy and black with heavy throttle. Been fine since. What could have caused that?? The only thing I can think of is I did not lube the eccentric thingy under the diaphram when I put it back in. Wasn't sure if I should, since it came out clean and dry. Maybe it was sticking? Should I put some oil or grease on it?



Now I not only like my truck, I love the new found Cummins power!

 

[Nordby]

Just a few guesses:



Perhaps the fuel delivery pin, that rides on the eccentric attached to the diaphram was stuck. A few notes in here have mentioned they found the pin stuck.



Another possibility, less probable, is that your pump timing is off. On cold start, your KSB selenoid advances the timing. So your test drive initially could have been when the timing was advanced. Then, 20 minute drive to your friends, it should have turned off. And within a few minutes of starting it back up, it would have turned off again. This behavior would be repeatable, so if it didn't happen again every time, I'd go with the first guess.



jon

 

[Matt S]

Congrats! Your now addicted. I hope you have gauges to monitor temps as with adjustments they can climb faster than the tach. I had originally adjusted mine too much and lost my speed gov on the pump so it would rev REALLY easy. Something in the pump must have been sticking for there to be a change like that.

 

[J DeMaio]

Hey guys:

I'm thinking of doing these adjustments with a new turbo housing after I get my gauges installed. Two questions are: How do you know if you have one of the very few engines where you have to buy injectors? Did you all have to adjust the smoke screw, diaphram, and what about throttle linkage? Not sure what to do for sure besides the idle linkage. Any tips would be appreciated.

 

[JFitzgerald]

TST Instructions

Originally posted by J DeMaio

Hey guys:

I'm thinking of doing these adjustments with a new turbo housing after I get my gauges installed. Two questions are: How do you know if you have one of the very few engines where you have to buy injectors? Did you all have to adjust the smoke screw, diaphram, and what about throttle linkage? Not sure what to do for sure besides the idle linkage. Any tips would be appreciated.

Can't answer about injectors, but as far as the pump adjustments - Go to the TST website (you can find it in the links section of this site) and print out the instructions they give on the VE pump adjustments. It is about 4 or 5 pages and is very detailed and helpful. Once you get started, I think you'll find it is pretty easy.

 

[J DeMaio]

Hey J:



I have the TST Booklet. Did you have to adjust the idle linkage? I'm a little nervous about doing this myself but think I'll be all right if I just do it.



Another question. What's the best thing to do for turbo lag? Case 500D posted to me that he turned the Starwheel? to get boost off the line and said that turbo lag is non-existent. Should I do this or just get a new 16 cm turbo housing?



Thanks for the suggestions.

 

[JFitzgerald]

Originally posted by J DeMaio

Hey J:



I have the TST Booklet. Did you have to adjust the idle linkage? I'm a little nervous about doing this myself but think I'll be all right if I just do it.



Another question. What's the best thing to do for turbo lag? Case 500D posted to me that he turned the Starwheel? to get boost off the line and said that turbo lag is non-existent. Should I do this or just get a new 16 cm turbo housing?



Thanks for the suggestions.

I did need to adjust my idle back down after doing the other adjustments. Access to this screw and its' locknut is not the best. I used a small chisel to tap the locknut loose from above, and then needle nose vise-grips to turn the screw from the front end. The back end has a slot for a screwdriver, but I couldn't get at it. Don't worry, just mark everything's original position with a fine tip marker before you move it and it can always go back.



Even though the improvement is big, mine still has noticeable lag, so I plan to change the turbo housing. Part of the adjustments described by TST includes the star wheel adjustment. I believe I went 1/2 turn to start with.



Just go ahead and do it. Sure put a big on my face! The best part is it was free. I have always been after more HP from gas engines, and I never got it for free!

 

[NuttyMopar]

Yes, making those adjustments do make a BIG difference. Makes it feel just like a gasser, only better because of the smoke.

 

[JFitzgerald]

Originally posted by Matt S

Congrats! Your now addicted. I hope you have gauges to monitor temps as with adjustments they can climb faster than the tach. I had originally adjusted mine too much and lost my speed gov on the pump so it would rev REALLY easy. Something in the pump must have been sticking for there to be a change like that.

Which adjustment did you go too far on? Just wondering so I don't get carried away.



Thanks guys for the input. I think it must have been the fuel pin that rides on the eccentric that was sticking.



Should I lube those parts?