removing pmd without taking intake off

[Jim P]

For a while, I have been wanting to mount my pmd to a cooler and also remove my fuel calibration resistor so I could hook up a potentiometer.

Well today I made a special little tool to take out the screws and I did get the pmd off the pump without taking off the intake or anything. All I had to do was loosen up the pump nuts and turn the pump toward the passenger side.

I am planning to extend the wires and mount the pmd behind the grill right beside the horn.

I did remove my fuel calibration resistor and hooked the pmd back up and started the truck but even without the resistor it set no codes and didn't run any different.

Once I hook up my potentiometer how can I get the computer to recognize the new ohms value of the potentiometer. I know some people say you have to perform tdc relearn but how can I do that on a 95 without a tech 1.

Jim P.

[charliepeterson]

You need a Tech II to do the TDC Offset relearn. The chip in the PMD really doesn't increase the fuel rate as much as getting into the computer programing. The ECM only looks for the chip value every 40 starts or something. If it doesn't see the right chip then it will turn on the light.
The OBD I trucks like yours are the easiest to increase the fuel rate. The ECM has a large prom chip which can be replaced. Stock fuel at WOT is only 63mm. A replacement prom reprogrammed to heavy duty specs. will deliver 80mm of fuel with a #9 chip in the PMD. Other benefits to a "Hot" ECM prom are transmission shift points and elimination of EGR functions.
OBD II trucks already have this high fuel rate curve.

[Jim P]

I realize that a different chip would give me better fuel delivery but I just wanted to get a little extra without much money. Mine had a #3 resistor so I figured that turning up the potentiometer to just under what would set a code would give me a little more fuel. I already have the boost covered with my homemade boost controler and the truck has a manual tranny so there is no computer control there.

Do you actually have to start the truck or just turn the key on 40 or 50 times to recognize the new resistor. I have turned the key on and off well over 100 times and it still has not recognized the new resistor value.

My pmd relocation seems to work very well. I drove around quite a while and when I got back the IP and intake were too hot to hold your hand on very long. The pmd and cooler were not even warm.

Jim P.

[sturgeon-phish]

Jim,
How did you make the removal tool? I would imagine you could make and market it.

[Jim P]

Here is some pictures of my relocated pmd and also the wrench that I made to remove the pmd. The wrench is just a flat piece of steel with a 1/8 hole drilled through it. Then I cut the end off of a torx bit and brazed it in the hole. At first the tool was only about 3" long. This worked ok for the top screws but I had to put a couple little bends it and extend it for the bottom screws.


http://myweb.core.com/photos/jpfarmer@raex.com/95chevy2500hd/

Jim P.

[sturgeon-phish]

That's pretty slick. I also like your mounting location. I have my original pump and PMD, and 50K of the factory warranty to go, but when the clock is up I'm moving the PMD.