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Discussion Starter #1 (Edited)
How to mod the 94-98.5 P7100 injection pump a

First off Recommended items for the mods within

Egt Gauge
Trans Temp
Boost gauge

Better Safe than sorry!!!

ok first off things you will need,

1. General socket set
2. a Chisel
3. some way to grind the stock plate or to buy an aftermarket one (both can be done with relative ease)
4. Brake parts Cleaner
5. A Flathead Screwdriver
6. Patience!!!! Take your time and do it right!!!!!!

First thing lets talk a little on how the pump actually works

There are four major components that we will be working with

1. The fuel plate
2. The Aneroid Fuel Control (AFC) Module
3. The smoke screw, or in technical terms,the preboost screw
4. The Starwheel adjustment

Heres a cutaway for visual reference



Now lets talk a little about what these components do

1. The fuel plate is a high rpm fuel stop, when the motor is under boost the governor arm comes into contact with the fuel plate and the fuel

plate determens the maximum amount of fuel in a certain rpm range, the bottom of the fuel plate is the low rpm range and the top is the high

2. The afc controls when fuel comes in, at part throttle or low boost situations the foot on the afc stops the governor arm from contacting the

fuel plate

3. The preboost (smoke) Screw, this adjusts how much fuel is allowed before boost it works in part with the afc foot, the smoke screw, acts as a

starting point for the afc,

4. the starwheel adjustment determens at what boost level the afc foot moves back exposing the fuel plate you can see from the pic there is a

rubber diaphragm, when the pump is hooked up on the truck there is a boost reference line coming from the intake manifold to the back of the afc

housing, when boost comes up the foot moves past the plate allowing the governor arm to take on full fueling according to the plate profile.

Now that we know what were working with and what it does lets get started!!!!


First off remove the intake air horn There are 5 bolts and a clamp Set it aside, makes reaching what we need 100x easier



after that you will see the fuel lines and the top of the afc housing, take the clamp on the fuel lines loosen the bolts and slide it towards the

valve cover out of the way, there will be four bolts on the afc housing one will have a rounded head, this is where the chisel comes into play,




take the chisel and hammer it into the head of the safety bolt and spin it out, as you can see i have already removed mine, take the safety bolt

to the local hardware store and replace it with a standard hex head, or put it somewhere easier to reach.

now once you get the bolts out carefully slide the fuel shutoff down just enough to slide the afc housing up and out



Now you can see the top of the fuel plate,



its held in place by two flathead screws at this point you have a couple options, either you can

regrind the plate now or slide it forward and put the afc housing back on.

BUT REMEMBER!!!!!!

MARK THE STOCK LOCATION!!! this will let you see how far off of stock you are

SLIDING THE PLATE FORWARD TO THE RADIATOR = MORE FUEL

SLIDING THE PLATE BACKWARDS TO THE FIREWALL = LESS FUEL

If you decide to regrind the plate heres what the different profiles look like i went with the #100 plate



after grinding remember to give the plate a good cleaning with the brake parts cleaner!!!

Now reinstall the plate, where you want it and tighten the screws

now if you want more preboost fuel take the screws out of the back of the afc housing, this will expose the preboost screw






NOW REMEMBER

TURNING THE SCREW IN = MORE FUEL

TURNING THE SCREW OUT = LESS FUEL

now i recommend only going about 1 turn at a time slowly getting it where you want it, because too much pre boost fuel will smoke like a

train, but hurt low end performance, put the cover back on.

now after that, when you go to reinstall the afc housing it has a setting all of its own as well, Remember

AFC HOUSING FORWARD TO RADIATOR = MORE FUEL

AFC HOUSING BACKWARD TO FIREWALL = LESS FUEL

push the fuel shut off back up and start the bolts in the holes, set the afc where you want it, and tighten i went full forward on mine.

Re install the air horn making sure to tighten the bolts nice and snug!

Give her a test run and see how you like it, the mods will wake the truck up!!!

originally i went full forward plate, full forward afc, and reground the plate to a 100# profile and didn't touch the preboost screw, that gave

the truck a good jump in pulling power with minimal smoke

Now if you feel that you need the boost fueling to come in earlier, you can do that, remove the allen plug on top of the afc housing, this will expose the star wheel, REMEMBER!!!

SPINNING THE STARWHEEL TO THE ENGINE = BOOST FUELING COMES IN EARLIER

SPINNING THE STARWHEEL AWAY FROM THE ENGINE = BOOST FUELING COMES IN LATER

adjust starwheel as needed

if you have any questions feel free to ask, ill be glad to help!
 

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95 Ram 2500 original owner, 42k miles, yes 42k.., 5 speed manual. I want to raise HP to around 300hp. As everyone with common sense preaches, guages, guages, guages. Installed K&N cold air intake, have boost elbow, and will do 4" exhaust. I will install boost and EGT guages before changing anything else. Can I get to 300hp with sliding stock fuel plate forward, and, or the AFC as well? If not, what cut on fuel plate? I understand the AFC and how everything works together. When the star wheel is referenced, are we doing a few clicks, or talking about full revolutions? I understand if I pulled this hard, the clutch probably won't hold the power, and the tranny?????
 

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thanks for this, it is going to come in handy...I would like more instruction or your observations on the finer points of tuning..can you steer me somewhere that is as clear as this group of mods you posted.
I am a new owner of a 300K 1995 12 valve 4x4 auto...it seems a little lazy compared to our Duramax, but it should at only 160 HP...it is unmolested and I want to gain some power, with out giving up good mileage. Not interested in smoke, may tow a gooseneck long distances.
 

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95 Ram 2500 original owner, 42k miles, yes 42k.., 5 speed manual. I want to raise HP to around 300hp. As everyone with common sense preaches, guages, guages, guages. Installed K&N cold air intake, have boost elbow, and will do 4" exhaust. I will install boost and EGT guages before changing anything else. Can I get to 300hp with sliding stock fuel plate forward, and, or the AFC as well? If not, what cut on fuel plate? I understand the AFC and how everything works together. When the star wheel is referenced, are we doing a few clicks, or talking about full revolutions? I understand if I pulled this hard, the clutch probably won't hold the power, and the tranny?????
You cannot get to 300hp with the stock plate at all unless you ran giant injectors and you don't really want to do it that way.

With my 94' 12v, which was a 175 pump same as yours, here's the mods I did which gave me 325 RWHP and 710 RWTRQ.

0 plate full forwared
181 delivery valves from a 215 pump (stock DV's are 151's in 94-95)
AFC spring kit
3k governor spring kit
370 marine injectors
stock WH1C at 38 PSI boost
BHAF on the stock elbow
Timing bumped to 15 degrees

Now what I don't recommend is the 370 injectors. If you find a used set of 215 injectors and have them rebuilt they would be fine for 300 crank HP. You also wouldn't need a 0 plate full forward, you can probably use a 10 plate to get 300 crank hp with rebuilt 215 injectors and 181 or 191 delivery valves.
A 95 would have an HX35 which is fine, virtually identical to the WH1C but you wouldn't need to run 38 PSI at all. You'd probably be fine at 30 PSI. I only ran 38 in attempt to lower EGT's because of the marine injectors making it run hot. The timing bump to 15 degrees also lowered EGT's 100 degrees and definitely made a noticeable increase in power I highly recommend 15-16 degree pump timing.

You also don't really need the AFC spring kit, or mod the AFC at all. With the stock turbo it spools plenty fast, modding the AFC will just make it smoke more. The most I'd recommend is just sliding the AFC full forward, you may not even like how much that will smoke. If you don't, just slide it back until you get something more to your liking.

My truck was bone stock when I got it with 250k on the clock and with all these mods everything held up fine, even the clutch somehow but I'm guessing that it may have been replaced somewhere along the line. But, I'm sure that it was only a stock replacement nothing fancy.

Just remember, the NV4500 transmission does NOT like to be lugged in 5th gear. Just avoid that and you should never have problems with the trans.
 

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Ok I have a 97 cummins. I'v built the tranny diffrent torque converter. 5 inch exaust. Stage two injectors from Pensacola injectors. Our degree fuel plate wastegate has been adjusted. Gauges for egt trans temp boost oil presure and water temp. Truck runs great. Problem I'm having is slow off the line don't build boost utill it gets past 1500 rpm or it kicks in to overdrive. Why is that how can I fix? Think they adjusted the star wheel back too much when I took it in to have the injection pump timing turned up to 16 degrees. I don't have a line that goes from turbo to pump with a T that goes from thoes to the intake. Thaught that was odd. Where can I find the fuel screw? Can't see any of your pictures. How much hp do you think I have?
 
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