So I recently bought a 92 cummins, and the previous owner cranked it up somewhat. I still havent got any paper work on what he did, but he had industrial injection in SLC do it I believe, he basically said its got 60 hp injectors ( no idea size, possibly delphi) and that the pump has been tuned. I have no idea about fuel screw or anything other than it dosent idle down fast so you can catch gears easier or something, and holy crap does it roll coal! So the point here, the truck runs pretty hot if i dont pay attention. As in, i accidently found out that empty I can easily bury the pyro. It also runs like 32 pounds of boost. Now I watch my foot but I need to fix this!! I've also noticed at full throttle the smoke never COMPLETELY clears up. So my first question is will a different turbo cool me down? possibly a 60 mm upgrade or something like it? its still h1c according to the housing.

Also another issue I've noticed is when I'm towing, if I'm going slower and lug it (1500-1800 ish rpm) and i'm going up a hill and don't down shift from 5th, when it starts building boost it hops/barks/jumps or what ever ya call it... it starts around 8-10 psi and the more you go it just gets worse until you get to like 30 psi then it quits. Any idea on cause/solution here?

I'm new to Cummins so any and all help is appreciated!!

I'm still working on getting the paperwork from buyer, so if I get it, I'll update this!

 

It's called turbo surge and no the smoke will never clear up with those injectors. The turbo is obviously modified already if you're getting 32 psi. Get some good stock injectors and have them set to 300 Bar pop off by Bosch shop. If pump is that radical, it wont last long as the stock pumps usually fail around 75k to 150k miles as is. Your peak torque is at 1700 RPM, so if you want to keep momentum while towing, down shift at 1700 and try to keep cruise RPM around 2100 whenever towing. Also while accelerating while towing, rev to 2500 before shifting and you should be at 1700 in next gear. I've had a lot of customers complain about the gear splits on all the 5 spd trucks and explain to them the same concept. Also run a good brand of fuel additive every tank of fuel. I like Howes. You can get it at any Auto Zone, 1/2 gallon bottles for less than 20$. Carry a small 8 or 12 oz plastic bottle with it and general rule is 4 oz of additive per 10 gal fuel and those pumps will last a lot longer. Low sulfur fuel is toooo dry.

 

Ok, so is there a way to keep it cool without changing injectors or turning down pump? And Ill see what previous owner did to turbo I guess if it's not stock

 

A stock turbo can peg a 30 PSI boost gauge with aftermarket injectors, and yes, it'll be pegging the pyrometer at about the same time.

A bigger turbo would be the best thing to throw at it. Other solutions are water injection, a ported head/ camshaft or a better intercooler.

 

Which turbo would help to cool it down some?

 

Ok so the pump needs better tunning to clear out the smoke back out the smoke screw all the way get a boost controller and put it in place between the manifold and the injection pump (the top part where the diaphragm is) this will help alot with the pre boost smoke I run this and a boost control plate and 5x14 witch are 150 ish horse power injectors and a hx 35 and I have very very little smoke and lots of power and after this tunning the truck is faster now then before with everything maxed out and my egts and fuel mileage is better and drive ability is way better feels more like a gas truck around town and ready to get down when needed

 

I've had a bit of experience with the VE, and here's what I would suggest...sounds like the truck is turned up pretty good, but it probably doesn't have any more timing. You need another 5-10 degrees for the big injectors to work right. You can either loosen and advance the entire pump towards the head, or skip a tooth (which will be about 10 degrees). It will spool slower, but you'll get another 30-50hp and lower egts. Now for the rpm deal. You'll have to get over trying to make power at 1,500-1,800rpm, a modified diesel will be more like 2,000-2,500rpm, with the ability to rev to 3,000rpm with no problem. Lugging it will actually create problems now that you're modified.

A governor spring can fix this, but adjusting the pump linkage can actually do quite a bit. Revving it up another 500rpm will still be plenty reliable.

Also, you need to specify what burying the pyro is....mine goes to 2,000