First off I would like to say that this is a very informative site and I'm glad that I found it. Here's the deal, I just bought a '91 W250 CTD 5-Speed and I'm lookin to fix it up to tow with. It's going to be transporting atleast a couple of trucks, some quads, and a camper most of the time, I want to know what I can do to improve power so that I can tow all this and still do the speed limit (60-70mph) and possibly make the guys in the newer trucks look bad. I've been looking at alot of posts on here and have been getting alot of good ideas, but I still don't have a very clear picture. I have advanced the pump timing and installed a later waste-gated turbine housing, but neither of these has given it much more power. I already know that it needs the governor increased, as it stops revving almost instantly as soon as you shift and I got to put a brake on it to help slow it down. I got the money to spend just need to know what to do with it, thanks in advance.

 

Your truck should jerk the tongue plumb out of the wagon with no more load than you described.

Fresh fuel filters and air-filters will make a world of difference.

Those much smarter than me will be along to relieve you of some of your financial burden.

 

Ok get a EGT gauge then look in the sticky on how to turn up your pump. Its easy and free.

 

Big,

First off Welcome aboard, your financial situation will decrease dramatically the more you read!

Next, just a few questions.

1. By how much did you advance the pump timing?

2. What size turbo housing did you switch to?

3. I doubt its a problem, but do you know at what PSI your waste gate is set?

4. Is your truck intercooled or not? If I remember right it was mid year 91 they made the switch.

And from what I understand I think you're on the right path with the Governor spring idea. Once that and a couple more free mods are done, embarrassing the newer trucks shouldn't be a problem!

Good luck man!

 

Thanks for the welcome, to answer your questions
1. I advanced the pump timing until the pump hit the intake (I was told that that is about .5 to 1 degree).
2. I don't know the exact size of the turbo housing, I was told by my uncle (who gave it to me) that it is from a later, 2nd gen. truck.
3. I have no idea what the waste gate is set at, I assume that it is whatever stock was for the 2nd gen. trucks.
4. The truck is not intercooled, I read on here though that the intercooler from a 7.3 Ford Powerstroke will fit nicely, so I might try that at some point.

I have changed the fuel and air filters and I'm in the process of adding boost and egt gauges. One more thing that I wanted to ask about is how do you disable the clutch switch on the pedel?, that thing is driving me crazy. Thanks for all the help.

 

Check the throttle linkage for full travel, this is the cause of a lot of low power complaints.

Unplug the clutch switch and make a jumper wire for the plug - but for God's sake be careful!

 

Back your timing down to stock (should be marked) then advance till it rattles loud (about 1/16 - 1/8) till it hits the head is way to much!!
1/16 worked great on my 91.5.

 

I did only move it about an 1/8", it wouldn't move anymore than that because the boost line would hit the intake and I didn't want that. It seemed like it gave it alittle more power but not much. I will check the throttle linkage to see if it's getting full throttle. Thanks again for the input.

 

Timing alone will give you a little shot in the rear, but not much more than that. It may have already been advanced, it's hard to tell on a 16year old truck.

Read the stickies, and play with your AFc settings, then maybe a turn or two of your power screw. Since you're non intercooled, gauges are a must. You DID get a 40psi or higher gauge, didnt you? If not, swap it out for one. I pegged the 40psi gauge in my early 91 quite regularly with pump tweaks (stock internals, even), and PDR HX35-18. The 12cm housing may or may not be too restrictive. It was on mine for my use and liking. Keep an eye on temps and pressures.

An intercooler is a good idea. I think your stock injectors will flow adequately for your needs.

Daniel

 

Change your intake and exhaust. Lots of guys here don't like the K&N but I do. I think that people just clean them too often and over oil them and that's what lets particles through and gums up the turbo. I cut the top off my air box because the little opening in the front is a joke and it made a big difference. A 4" turbo back exhaust will wake it right up. You can try to buy one or do what I did and build it. As already stated, follow the instructions for pump adjustments and you won't be disappointed. I don't have a 5 speed so I don't know what the clutch will hold but be careful and plan on upgrading.