I just bought a 98 12v. The last owner had already installed larger inj(2 step's up. what that might be as far as size, I am not sure.). 4" exhaust from the turbo and a Araid air cleaner. This is the first diesel I have owned and im not sure what I am feeling is right, but the thing doesn't want to get out of its own way. I would have assumed that with the larger inj. I would see some black smoke coming from the tail pipe. I see none. The trans seems to be shifting alright, but I am getting it looked at this week just to make sure. I have been reeding the forums for a couple of weeks now and have gotten alot of good info. Like the KDP, which I have taken care of. I have also order gauges that I hope to get installed this week end. Today I shifted it manualy to see if it ran any better, NO. The only time it seems to run good is when it shifts into overdrive. So before I start speeding money on other improvements. I would like to make sure that it's running the way it should. Any direction would be greatly appreated.
Thanks Chris

 

It's probably running right.
Stock trucks are dogs from the factory in order to get the tranny though warranty.
Once you change the plate and make some adjustments it will wake up.
The injectors alone aren't enough.

 

That being said, than my thought process was to order the #10 plate, 4k govenor springs and most likely the RV's. I don't mind the smoke if I gaining torgue. Then change the timing, but to what? I do not want to loose any low end torque. I see people changing to around 16 degrees. Is that going to be much?

 

16-17 would be perfect for you.

 

Overflow valve. Mine was feeling kinda sluggish, I replaced it and couldn't believe the difference. Also gained a little fuel milage (when I keep my foot out of it).

For me it was money well spent.

Your fuel plate is adjustable. Moving it forward a little will make a difference.

Also your AFC has a starwheel under that allen plug. Rotate it - top towards the engine - This will help a little with bottom end. Caution, too much will cause smoke, but all you do is back it off a little.

As for timing, mine has been set at 16.5-17 degrees for over 140,000 miles now with no problems. Mine does have the smaller pump though, I've read that can be a good thing for the smaller pumps. Unfortunately, mine has always been that way so I can't tell you how much of a difference it made in power.

Mine pulls quite well. Stock injectors, stock fuel plate (forward 1/4"). So surely yours can be made to run a little better before you spend too much $$$

My suggestion before you do anything is to get at least an EGT gauge. That with a boost gauge. That will go a long way to help you keep things together longer.

Good luck

 

What is a overflow valve? Thanks for the info. Gauges on the way

 

An overflow valve is the pressure regulator for the fuel delivery system and is probably the single most prone to failure part on a 12 valve.
They just wear out.
If you don't have the means to check your fuel pressure at the inlet side of the injection pump replace the OF valve.

You won't find a better price on an overflow valve than here

Precision Diesel Injection and Turbo Inc.
Marty Tompkins
888-734-7349
$35 + $7 shipping and handling.

Replacing the OF valve is a five minute one wrench job if you don't drop the sealing washers, stuff a rag under the valve to catch a falling washer. Remove the old valve and put new one in it's place. Occasionally the notch in the manifold you see to the left of the OF valve in the picture needs to be filed or ground a little to allow the old valve to be removed. Don't bend the line to remove the valve, it will make it very difficult to line up again. New style OF valves don't always have the retainer on top that says not to remove, don't worry it's just a design change.

The object in the lower left corner is the oil fill cap.

 

great, I will check the fuel pressure.