New IP - move PMD??

[mobilevet]

Looks like I'm going to put a new pump on... do I take the PMD off and remote mount it? What's the risk of hurting the PMD in the process of removing it??

Also I was told something about needing to have the PMD "setup" for the pump if you were to hook a new one up instead of the one that came factory on the pump... ???

Thanks

[DmaxMaverick]

I suggest you do. Move it to a cool (like outside the engine compartment) location and mount it to a good heat sink. You'll need an extended harness for this. Search and read the threads on this, as well as the TDP articles. Not sure how you'd damage it unless you use a hammer to remove it (not recommended). It should fall off (so to speak) once the screws are out.

The only calibration between the PMD/FSD and the pump (actually, the PCM) is the calibration resistor in the harness that plugs into the module. It is a card that fits inside the connector. Have a look at the bottom of THIS (http://www.thedieselpage.com/members/tt99-9.htm) article for a picture and removal instructions, if needed. The resistor is pretty much a non issue. As long as one is there and the PCM is happy (no DTC's/SES), all is OK with it. Changing the resistor value (replacing the resistor card with another) can increase/decrease fuel volume (more/less power), but the change is minimal, if noticed at all. If your resistor is in place and you don't have related codes, it's OK.

Another option is to leave the PMD/FSD where it is, and install a remote mounted (different FSD) module. This will give you an option if the relocated module fails. You can plug in the OEM location module and get home. But, since you already have the pump out, you can just keep a spare in the glove box, and switch it as needed. It's up to you how you want to do it, but I suggest you have a spare on hand in any case. It can sure make a difference between a nice trip and a miserable one.

[JohnC]

Just FYI, plugging the cable back on to the stock PMD is extremely difficult to do without damaging the connector on the PMD, unless you remove the intake manifold. (Ask me how I know...)

Better to take it off and put it in the glove box.

[DmaxMaverick]

I won't disagree, that it isn't easy. Never said it was. But, I've done it dozens of times and have yet to break a connector. The biggest PITA is dropping the resistor into the valley. I agree, though. Having a spare "in hand" is a much better option. That is, if it is an option. Most folks facing this don't have the pump out.

[JohnC]

Well, I didn't break it, either. Just bent a pin over....

You must have a better set of pliers than I have.

[DmaxMaverick]

No pliers. 2 long screwdrivers (extended fingers), and patients. I have a long curved hemostat handy "just in case", but haven't had to use it, for that.

[mobilevet]

Hi guys - thanks for the comments and links... very helpful. I wasn't sure how tight the FSD was glued to the pump, sounds like it isn't glued at all.

I read the article that you linked to as well. Let me ask a stupid question:

The article says that if you put on a new FSD then you need to take out the "calibrating resistor" and put it in the new FSD.

Here is the question. I've heard and read over an over about getting an FSD and mounting it (somewhere) as a back up. Then when you are having problems just unplug the current FSD and plug in the new one. Now, if you have to move the calibration resistor when putting on a new one - how would you install this "Plug and Play" spare - it wouldn't have a calibration resistor would it?

This makes me wonder about the FSD in my truck. I'm owner #4. Owner #2 says he put a new FSD on it at about 200k due to failure of the FSD on the pump - which is still there. I have no idea if he did anything but unplug the old one and plug into the new one. Also, owner #3 put a new FSD on at about 229k - says the FSD owner #2 put on was doing fine, but just wanted a "backup", but it was the latest FSD that was plugged in when I bought it - not the one put on by owner #2 - you with me??

Is there anyway to check and look for this calibration resistor on these second and third FSD's???

Sorry if this is confusing... believe me, I'm confused as well, and is one reason that I'm very close to just putting on a new pump so that I can just start from scratch.

thanks for the thoughts.

[JohnC]

I think the Kennedy extension harness allows you to install the resistor in the junction between the factory harness and the extension, so switching FSD's retains the resistor. Otherwise, you need to swap it to the new FSD, or, if the original is on the pump, get a second resistor.

A scan tool can tell you what resisitor is currently in use. The value is not real critical. If you don't know what it is, use a 5. If you leave it out, eventually the PCM will complain and default to the fuel map for #2.

DMM: so now you're making fun of my stubby fingers?

[DmaxMaverick]

Yes. The OEM resistor would be installed in the connector of the OEM harness and the extension harness. No need to mess with it while swapping FSD's. That said, you wouldn't really need the OEM resistor, or in that location. A resistor (any resistor of the correct value) can be anywhere, as long as it crosses the 2 wires. Some folks have installed a POT in place of the resistor for some variable fuel rate adjustment, but it's not like a power programmer with a "knob" for power adjustment (really long, really old argument). It would eliminate the need for the resistor, though. You could use a minifuse receiver inline in the harness, anywhere, and "plug in" Radio Shack resistors at your leisure. There's no rocket science here, and the PCM only cares about it once in a great while (it isn't a constant value monitored by the PCM). As long as the PCM "sees" a resistor value, within the range when it polls it, it will be happy. Take the resistor out and the PCM will complain a little when it looks for it, but the engine will still run, but at a default fueling value, with the SES on. It's just not that critical.


John
Not making fun of anything. I've been blessed with very large, but nimble hands/fingers (XXL+). Sometimes a liability, as they don't fit just everywhere. I have a collection of "extended fingers", like hemostats and suture clamps, to help where I can't get them. In this case, the eyes are usually the limiting factor. If you are suffering from "finger envy", I can't help you with anything other than alternative solutions. Size doesn't matter, as long as you have and use your tools correctly.

[JohnC]

Sheesh! Now you're making fun of how I handle my tools...

;)

[joe bleaux]

DMM,

Make sure that you don't have acromegaly, as seen on Foxnews

Joe


Yes. The OEM resistor would be installed in the connector of the OEM harness and the extension harness. No need to mess with it while swapping FSD's. That said, you wouldn't really need the OEM resistor, or in that location. A resistor (any resistor of the correct value) can be anywhere, as long as it crosses the 2 wires. Some folks have installed a POT in place of the resistor for some variable fuel rate adjustment, but it's not like a power programmer with a "knob" for power adjustment (really long, really old argument). It would eliminate the need for the resistor, though. You could use a minifuse receiver inline in the harness, anywhere, and "plug in" Radio Shack resistors at your leisure. There's no rocket science here, and the PCM only cares about it once in a great while (it isn't a constant value monitored by the PCM). As long as the PCM "sees" a resistor value, within the range when it polls it, it will be happy. Take the resistor out and the PCM will complain a little when it looks for it, but the engine will still run, but at a default fueling value, with the SES on. It's just not that critical.


John
Not making fun of anything. I've been blessed with very large, but nimble hands/fingers (XXL+). Sometimes a liability, as they don't fit just everywhere. I have a collection of "extended fingers", like hemostats and suture clamps, to help where I can't get them. In this case, the eyes are usually the limiting factor. If you are suffering from "finger envy", I can't help you with anything other than alternative solutions. Size doesn't matter, as long as you have and use your tools correctly.

[DmaxMaverick]

DMM,

Make sure that you don't have acromegaly, as seen on Foxnews

Joe


Nope. Except for my height, everything's proportionate. But, sometimes I feel 10 feet tall and bulletproof.

[dandl]

Put a rebuilt pump on my 1996Z71 about 2yrs ago, I did not move the PMD, been down
that road already, unless you want to void the warranty that comes with the pump, if
you are buying a rebuilt pump, truck has been running great since i changed the pump.
Oh!!! I did the work myself.

[mobilevet]

Thanks for all the comments. I feel like I have all the info I need to do the deed if needed. I was afraid that moving the PMD might void the warrenty.. from what I can tell it is only a 12/12 warranty anyway.

Thanks again.