PDA

View Full Version : Changing the pmd



digital dummy
11-26-2009, 04:46
What was a 15 minute job has now got me stumped.

I have attached pictures to show my setup. I don't know if it is completely different, or very similar to everyone elses, but I have no idea how to get to the pmd. The space is extremely small, and with a pair of long needle nose, I can just barely reach the wire, but the wire is not long enough to pull up to hook onto the new extension cord.

I started to take the bolts out of the top piece (not sure what it is called), but then I thought I best check to make sure it's okay to take it out. I tried prying on it, but it wouldn't budge. In addition, the long air pipe leading from it over to the filter is also cast, and it looks like I would have to unbolt that too.

Is this the correct proceedure? How much force should I use to take that big piece off with? What about that smaller piece on top of it. I see the gasket is leaking. Am I going to run into problems taking that off?

Hopefully the pictures will be clear enough for someone to see my predicament.

Can't seem to upload the pictures properly....way to small.
don't know if you can tell what I mean or not.

As you can see, I'm not much of a mechanic, but love the challenge.

By the way, I am putting a new pmd near the front bumper.

thanks

DD

Robyn
11-26-2009, 08:33
Hi there.

Pics are a little small but no worries.

Leave the old PMD where it is.
You dont want to put a fresh one in that hole anyway.

If you remove the top hat off the intake this will afford a tad more room to work.

Using slim screwdriver work the little retainer clip up so you can slide the connector to the rear and off the old PMD.

I have done this many times, so I know first hand that it can be done.

You will need a fresh PMD (DTECH is a good choice) and a remote cooler along with an extension cable. (5 Footer works)

With the plug loose from the PMD, carefully fish the plug and wire harness out and up so you can get to the plug.

Mount your fresh PMD to the cooler and locate the thing in a cool place with plenty of airflow.
Behind the LH battery is a popular spot.

I like the inside of the fold down shield thats below the radiator.

NOW *********** you will need a new resistor to go with that new PMD (goes into the plug socket first before the plug. It fits one way only)

You wont be able to see the number on the old one so get a NUMBER 5 it will work fine.

Mount the cooler, plug in the extension cable to the PMD and to the plug you removed from the OLD PMD and your set.

Replace the top hat (may need a fresh gasket) good to go. :D

The old PMD can ROT where its at

If you ever have to change the IP just remove the PMD then and if you replace the IP have the shop leave the PMD off.


Hope this helps


Missy :)

digital dummy
11-26-2009, 10:41
thanks for the help.

does that center dome pull off hard?

I don't want to force it and crack it.

thanks again

DD

By the way, the kit came with a number 9. I read it doesn't make alot of difference. What do you think?

digital dummy
11-27-2009, 05:27
Here's a shocker !

I managed to get the wire out without too much problem, but as I wasfiddling with it, the old pmd slid sideways !

The entire pmd was being held in by 1 bolt. I could literally spin it sideways by hand.

Initially it was line up properly, so I didn't notice it.

So the question is, could the pmd actually be ok, but just poor contacts?

Would the truck run as if it has a bad pmd with this setup? I could set rust all over the baseplate of the ip, but does that really matter as long as the electrical was working properly?

Might sound like a foolish question

thanks

DD

Robyn
11-27-2009, 07:09
The PMD is not connected to the IP for any reason other than as a heat sink.

The fact that the PMD was not tight probably hastened its demise.

Just abandon the thing in place and install your new DTECH or Stanadyne PMD on a remote cooler and be done with it.

Having a poorly mounted PMD will result in a failure. As far as anything else goes, its a moot point now.

The Manuf's decision to mount the PMD in that Hot little Hell hole in the first place was the foolish part.

Unfortunately there were issues between GM and Stanadyne I am told that precluded GM making other choices.

We will never know for sure what exactly transpired.

I have also heard that Stanadyne engineers told GM that they needed more R&D on the DS setup before they went into production but GM decided to go anyway.

Any of us who have owned some of the early 6.5 electronic injected trucks (Bought new) lived through that night mare.

I had a 94 GMC DaHooooley that had all the usual Gremlins that came as standard equipment on the early ones.

Had a 95 Burb that went through 4 injector pumps while under warranty.

Now I just carry a spare PMD in the glove box already mounted on one of those manifold mounted coolers.

It can be changed in a couple minutes along side the road.

Having the main PMD remote mounted out in a cool spot is a great plan.
Having a spare that you can access quickly and just swap the plugs is a blessing while on the road.

My Burb has one of the OLD SOL D units mounted up top and all it takes is about 30 seconds to jump out toss open the hood and swap the plug from the extension harness over to the SOL D and jump back in and go.

Been there done that.

Dont forget to pick up the number 5 resistor.
It is very obvious how it slides into the PMD plug socket, just orient so the contour lines up correctly and press it into the PMD and if need be carefully help it down to the bottom with a small screw driver a little nudge from side to side as it slides over the pins.

The #5 seems to keep the ECM Happy no matter what the thing had originally.
With a number 9 the ECM may complain at some time, if it does you can clear the code and swap the resitors out.

The "Top Hat" or air pipe is bolted to the intake manifold with (6) six bolts from the top.
Once these are removed the top hat will come off. It may need a little persuasion qith a soft hammer.

Also remove the tie bar and the connector hose at the turbo.

Depaco makes a great replacement gasket.

Keep us Posted.

Robyn