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Help please

I looked at the link, it looks just like the one I bought off amazon. I would think it or the one off amazon would be an inexpensive way to test and determine if the op needs a PMD. I hate the fact that the good ones are so high priced. that's why I still want to dissect the bad ones and come up with a way to have replaceable parts and or change out the items that create the most heat for components that don't break down so easily.

somewhere in my searching I ran across a schematic for a PMD, but couldn't identify the internal components in order to build one from scratch. MrMarty sent me a dead one to attempt to dissect. I've done a little poking and prodding on it but that stuff they encapsulate them is hard crap! was able to soften it a bit in some boiling water to get some out, but after it cooled the stuff got harder and wouldn't soften up anymore with heat. I'm hoping that one day I can find one that has some softer crap or find a way to dissolve it all saving the innards for identification. :)
 
@dbrannon79
Spend time searching the internet and you will find people that already took pictures, drew up schematics, etc. Search enough and you’ll find some built some with external drivers, liquid cooled units, etc.

This is a road traveled by several people and a couple of them had some interesting ideas.
 
I have heard it is them oval shaped things on the bottom of the PMD that gets hot and fries. I dont know that for a fact though. I read that if You can find those things in an electrical shop, remove and replace the bad ones then they will run a very long time.
 
I've never heard of a digital one before! those silver transistors on the under side of the PMD's do get very hot and is what kills them. I've always thought they were ether under rated or over driven for the application. sort of like how a 12 to 120 inverter is made. all the circuits are bassically the same other than the transformer and the transistor drivers. on those all you need to increase the wattage output is install a larger output transformer and transistors that can handle heavier loads of current. I have rebuilt one before in my past electronic tinkering to revive one that I smoked lol. I had a theroy on the PMD's that one could remote mount the transistors and double stack them by essentially using 4 transistors but I would need to study the circuit on how they were wired into the PMD. most of the time items like these are simple circuits that were built using the bare minimum rated components. "beefing" some of the components up usually makes them indestructible for the application they were made for.
 
The worse the ip is worn, the more the load on the drivers and the more they heat up.
Lube and proper incoming pressure has big impact. But it isn’t just over all heat, how drastic the temp swing is also does it. Thermal changes cause expansion and contraction and break connections inside the unit. That is one of the biggest improvements made on the new ones and why they offer lifetime warranty now- which was never done before- the better connections and better potting to hold them secure.
 
Honestly all three of mine are from AutoZone.. 2 extras on heat sinks ready to go.. I fried one about 6 months after I got the truck and had the money at the time so I bought 3.. extra 2 have been behind the back seat ever since .. oh well exta security if needed.. just surprised this one has held up so good for so long..being AutoZone brand
 
PMD is not a brain. It is a signal power amplifier from the brain. But it is not just an amplifier, PMD controls the valve inside the IP, it is a moving solenoid rod. Since this valve is a moving part, it does not close instantly, the PMD detects the moment when the valve is full closed and issues an impulse to the brain. the brain (PCM) takes into account this time between the start of closing and fully closed, and calculate the amount of fuel by adjusting the pulse width.
Valve:
IMG-20160816-WA0018.jpg
IMG-20160817-WA0025.jpg

Pin "A" from PCM to FSD(PMD)
Pin "E" to PCM from FSD(PMD)
Screenshot_2021-12-19-13-44-54-40_e2d5b3f32b79de1d45acd1fad96fbb0f.jpg

These wires carry impulses. the wider the impulse, the longer the fuel will be supplied

IMG-20160812-WA0026.jpg
Blu line -from PCM.
Yellow line -to PCM
The distance between the edges of the pulses is the closing time.
This time can be viewed in TECH 2
Screenshot_2021-12-19-13-57-02-75_965bbf4d18d205f782c6b8409c5773a4.jpg
 
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