I'm new here so please forgive me, I have recently inherrited my dad's 92 d250 club 2wd. He loved the truck but it was to big for him. Since I got the truck it has very little power,(friend has same truck, stock also- but with a lot more power) I have noticed on the back of the injector pump that the vacuum line the comes out of the block is not connected. could this be my problem? If anyone can help I would greatly apprieciate it.
P.S. the truck is completely stock and a daily driver

 

It sounds like the AFC tube (the "vacuum line") is broken. This tube is supposed to supply boost to the fuel pin, which moves to supply more fuel when there is boost, which makes more power. Fix the tube and you'll fix your power problem. Cummins should be able to sell you the parts you need.

 

Thanks I will try to get the AFC tube. By the way, is there anyway to check the KDP without opening everything up? the reason I ask is there is a good oil leak in the front of the motor- 2qt a week. cant find where its coming from though
thanks again, MAP

 

Well, you can check the gear case for damage where the KDP usually gets punched out. Stand on the passenger side of the truck and look at the gear case jusr below where the fan hub bolts on. Shoot some brake cleaner on it and scrub some, if the case is cracked ther you can be pretty sure the KDP dropped. If your oil leak seems to start around that area of the engine the KDP is likely the culprit. If it starts low on the engine it's the vacuum pump or the crank seal.

 

Thanks Wannadiesel, the case doesnt look bad. is it hard to fix the KDP? by the way I have the parts on order should be here tuesday? I hope that will give me some pep, can you tell me what a 'BHAF on Old Smoky mount is and why is everyone's silencer ring MIA? I've been told it does nothing except make it quiter. Is there anything I can do to get more acceleration without alot of money?
Unfortunatley I'm kind of stapped for cash.
Thanks again, Michael

 

Well, I can report on why everyone takes out the Silencer Ring. Just for that reason... SOUND

It doesn't make a lot more of it but it sure sounds nice hearing that turbo whine right up.

As for the BHAF mount. Well worth the money. It replaces the Stock Air filter and gives you much more air. It would then allow you to turn you fuel screw up a little also which equals out to more horsepower. I would strongly suggest getting gauges first so you can monitor your adjustments and possibly save your motor. Too hot and pistons do not like that. Old Smokey fuel pin I can not describe as I do not have one... yet. Worth the money from what I have been hearing as it allows the fuel rate delivery to come on stronger and stay on longer compared to the stock one. Maybe some day, saving for Rip's 4" exhaust for now. Too loud being straight piped in my neighborhood.

 

Thanks for all the info you guys are great. Where do you get a BHAF mount and what is it really called. besides pyro what other gauge would be next?
thanks again, Michael

 

It is called the BHAF mount (Big Honking Air Filter) and it came from someone on this website or TDR's website. I would do a search and you might be able to track it down that way.

For gauges, I would install a Pyro & Boost at the least. Others install Oil Pressure and if you have a auto, Trans temp. Those are the basic ones but other start installing whatever they can to monitor things. Rear Diff & Front Diff Temps, Fuel Pressure. Anything you can think of to monitor. I would also install a Tach. Just make sure it is for a Diesel and not your typical racing tach. Your motor only revs to 3500 - 4000 rpm or so. Depends if you have the governor springs on or not.

 

Unfortunately I'm still completely stock. Ill look into the BHAF and the gauges, just dont know if I can afford them. I think I'm going to the FALL BRAWL in Dillsburg PA. they say there is going to be alot of vendors there. at the very least I should learn something and get info for getting parts. Hopefully I will run into WANNADIESEL. just trying to learn more about this wonderful world of diesel

 

What is the "FALL BRAWL"?
WWWWW and How?

 

look in special events for link(I dont know how to put the link in here yet) its Oct 9-10 in Dillsburg PA 17019, it should be fun.

 

Alright, let's see if I can sort all this out.

The BHAF mount is no longer made, but if you look in Bumpytruck's gallery he was nice enough to make a template so everybody who wants one can make one. BHAF part numbers can be found in the tech facts section at the top of the screen, a BHAF costs about $50.

You don't have a silencer ring on your truck, they are found on '94 and newer trucks (my turbo is off a '94).

I'll probably be scolded for saying this, but it's pretty safe to play around under the AFC cover on the pump without gauges as long as you aren't hauling heavy or towing. Just don't mess with the main fuel screw. And notice I said "pretty safe" not definitely safe - and also no towing or heavy loads. Info on pump tuning can also be found in the tech facts section under 1st gen tech facts.

You also won't hurt anything by advancing the pump timing, this will make the truck a little snappier and help the fuel economy.

 

hey Wannadiesel thanks, you are the man. Now If i can only find the AFC thingy and advance the pump timing
I think what I have to do is find a manual on this truck so I can find this stuff that you guys are talking about.
Thanks again, Michael