Can anyone tell me the values in ohms of the calibration resistors on the 6.5? The reason why is that I am currently in the process of de-capsulating a Stanadyne PMD/FSD(Poorly Made Device or Friggin Stanadyne Defect) and working on a schematic. When and if I get this done I want to make my own FSD but better (Built in varible calibration). I know very little about diesels but a lot about electronics. I aquired a few bad modules from a local diesel mechanic (OFI thanks!) and I have already found some intial problems with the design besides the fact that they put the unit in a very hot area. First the pair of MJ15004 transistors are in parallel in the circuit. I can only guess that the engineer found that one couldn?t handle the load so he paralleled another in to share the load. Well when you parallel transistors they are a little different than other components. You must have current-equalizing emitter resistors for the transistors. These resistors are a MUST when paralleling transistors, since the transistor with the most gain will conduct most of the current and blow-up or heat up to a extreme temp while the other transistor does nothing. This I found is not apparent in the Stanadyne PMD module. I surmised that even if the transistors themselves do not burn up with this thermal runaway effect that the heat that they produce is cooking the surface mount components and their solder pad connections that Stanadyne decided to put directly behind these little heat makers.(Cool down and works, heat up and don't) This is only what I initially found, who knows what else I will find wrong when I finally trace the circuit out. I also am in the process of hooking my ocilliscope to the PMD. I've lengthened the cable and put a big heat sink on it. The connectors you need to build this are Delphi part numbers 15336022 and 15476159 http://www.delphi.com/products/connect/ good luck though they are still hard to get. Anyway My truck has no calibration resistors in the connector so I can't check them. (What a joke putting 2 little resistors in a connection plug! Electronic design afterthought!)


On another note, I have a 95 3500 Chevy 6.5 TB that I recently aquired and incedently caused me to become familiar with this PMD module. It would start and run fine all the way to work (6am and cool) When I went to leave work it would stall within the first block. I could get it started but would run with the check engine light on and no power. I did a search on the net and came across a site with a guy that is supposably a GM Diesel Tech (I think thats his handle?) He billed the PMD as the cause of everything from the economy to the war in Iraq! (Just kidding) And also thru in a plug to buy his cooler with the Patented extension cable! (How do you patent a cable?) I didn't buy his (Made my own) But this started me on the PMD kick. I recently bought a PMD as my wife did not want to wait for me to finish my own so we could go camping(Smart). I put the new module in and started the truck, made it about 300 yards and stalled. Started back up fine but with the Check Engine Light on and no power. Changed the OPS and checked the lift pump and the same thing. I had this problem before I put in the extension cable so I know it is not this. I have not checked the codes yet as my brainiac mechanic brother who has the scan tool was gone with his kid racing. What other things can I check though? Even if I find out the problem I will still continue my quest in making a more reliable and cheaper PMD.


Long winded first post but I tend to save everything up. Glad I found this site as I have read some very informative post from here. Hopefully it will keep me from running my truck off a cliff or worse buying a Ford!

P.S.


I will have pics of the module de-capsulated soon. Also you can replace the transistors on the PMD and remote mount them quite easily.(Gets the heat off of the rest of the components). If you are looking for something to de-capsulate the epoxy what I use is DECAP http://www.dynaloy.com/tech_data_sheets/Decap%20Web.mht use a old crock pot to heat it! Or just use a fine tip soldering iron to heat down to the transitor leads if you want to expirement with just changing them! (NTE61 is a direct replacement for the MJ15004's. I'll post measurements to the exact contact points on the board.)


Transistors usually just go bad but if one has gone bad and the other is taking the load it could theoretically cause erroneous signals when under a load! (Heat). So replacing them may work for you!


I am new to this forum and am usually busy in my spare time but I will keep updating as much as I can. If anyone else has went through this process and/or has a schematic let me know as this would save a little time. I do not yet know the full function of the FSD/PMD other than amplifying the signals from the engine computer to drive the Fuel solenoid. If that is all it does then this should be relatively easy and i'll use a wiser choice of components than stanadyne for this (Fets instead of transistors to start!).

I'm really interested in hearing about your improved driver.
It's funny but I asked GMdiesel tech what was patentable about an extension and he told me I'd get sued for making my own.Edited by: quantum mechanic

I'm at work right now covering for a guy on swing that's gone so I got a lot of time to burn. To bad I didn't take my couple of modules with me. I'll try to get some pics posted before I leave on vacation this Thurs. If not I'll be back on Mon. My first module I heated with a torch to burn the epoxy off. Didn't realize the surface mount components were right underneath. My second one is almost decapsulated all the way. It takes time cuz the components like to pop off while in the Decap. I have to write down their placement and values then put it back in its bath. Some of the components mostly caps and resistors the value got washed off so I have to desolder and read the value. It is painstaking and I will probably need another donor PMD to finish the schematic. If not I will reverse engineer it with my scope.(Easier copying then making better.) If my truck would run for more than 2 min I would hook it up but until I figure it out I'll just keep mapping the board out,Either way this beeatch is gonna get figured out.

It's funny but I asked GMdiesel tech what was patentable about an extension and he told me I'd get sued for making my own.


I would love to see him sue anyone! He does not have a leg to stand on. The connectors are a Delphi part and he did not invent the wire I guarantee. So what is he patenting? What is his patent number? All just BS. He just doesn't want anyone taking away his cash cow. I imagine if I get this done and sell it dirt cheap (Thats the plan) I'll probably get threatened also! If and when I will post the schematics anyway and people can either buy one done or make their own! At least that is the plan. I cannot believe that no one has sold these aftermarket though? been out since 1994, that's 10 years and no one sells a cheaper and better aftermarket driver? Soon hopefully!

Good old Steak-Sauce http://www.dieselplace.com/forum/smileys/Ermm.gif (AKA gmdieseltech or any number of other aliases). This guy is a complete joke. I'm suprised he didn't call you a TROLL, and a SPAMMER, and tell you what you are doing is ILLEGAL. Hell, he claims to have a patent on air.


MDHORBAN- Because you are new, you may not realize that a schematic of the PMD is THE Holy Grail to us. Many have tried and all have failed. Keep the info coming.


We may have to erect a statue to this guy when he is done!


Tim

MDHORBAN,

I have a # 7 resistor here( detached). Not being an EE, I'm not sure if I can read it's ohms with multimeter.
With setting on 1k ohm, it shows infinity just touching the two pin tabs. if I jump across the two (neg. on one side and pos. on the other) it shows 30 ohms.
I can get a #1 from my dad's '96 and try it also.
Your work here is monumental to us regular joes mastering this monster.
Individually we make can strides, collectively we leap forward. Edited by: quantum mechanic

http://www.dieselplace.com/forum/uploads/25C_fsdresistor.jpg
It wouldn't let me add it to the last post.

Hell, just list the colors of the bands on the resistor. That indicates its resistance


T

It's not a banded inline resistor, but the intergrated resistor is blue reads 4422

Thank you for the value of the #7. I'm not to suprised that it would be that low of ohms (30) I imagine that a #9 should be less ohms and a #1 will be more(Less resistance more signal more fuel and vice/versa).If I get the values of a #1 and a #9 everything else should be errelavent for my PMD as it will have a variable potentiometer onboard for calibration (That's the plan) Anyway here is some pics of the module about 90% de-capsulated. They are kinda blurry as my dang digital camera doesn't take close-ups well but it shows that I'm not just stroking it! This process of reverse engineering will take some time and as I have a full-time job and worse a wife! This is basically the first module that I have de-capsulated (The right way. Not counting the burnt one!)and most likely won't be the last. What I miss or accidently destroy in this module I will hopefully extract from the next and so on! Copying then making better is the easiest way ask the chinese! If not I'll look at the signals going in and out and figure it out that way!(Probably a combo of both)


http://www.dieselplace.com/forum/uploads/ZFA_pmdtopstart.JPGhttp://www.dieselplace.com/forum/uploads/Z16_burntfirstone.JPG (Right Pic)First attempt.Used a torch to burn off epoxy and found out that there was surface mount chips under there!


http://www.dieselplace.com/forum/uploads/A32_pmdB.JPGhttp://www.dieselplace.com/forum/uploads/FA1_pmdsideC.JPG(Upper left and bottom 2) One more try with De-Cap.Hard to see but a big cap(I think? Haven't measured) is hiding under the board on the side.Edited by: mdhorban

I dont think you need a variable potentoimeter...PMD operation does not depend on the resistor, the PCM in the truck reads the resistance and converts this to a 1-9 value but it is not a part of the PMD circuit.

The #1 is the lowest resistance and #9 the highest (except for 10-13).
I am still really interested in this. Electronics are sometimes beyond me but I've experimented with MAP signal resistance enough to want to learn more.
Anything you discover and want to pass along I will read.
I'll get the value of #1 for you since I have one not far away.

I dont think you need a variable potentoimeter...PMD operation does not depend on the resistor, the PCM in the truck reads the resistance and converts this to a 1-9 value but it is not a part of the PMD circuit.





If it is stuffed into the cable (As I understand) then it is essentailly part of the circuit. I understand that a variable pot would not allow you to make adjustments on the fly (PCM stores the value on start up only) But you would not have to have a pocket full of calibration resistors, just turn off key, turn to #5 or whatever setting and start again. I would eliminate the need to disconnect the cable and stuff a hokey POS in for calibration.

The #1 is the lowest resistance and #9 the highest (except for 10-13).
I am still really interested in this. Electronics are sometimes beyond me but I've experimented with MAP signal resistance enough to want to learn more.
Anything you discover and want to pass along I will read.
I'll get the value of #1 for you since I have one not far away.



Thanks again. I guess I answered my own question on this subject as the ECM stores the value it tells the PMD how much fuel delivery.High resistance just sets a number in the ECM, It says give me more fuel. Low restance opposite. (Thinking out loud)

Sorry PCM not ECM. (Damn Saturn that I use to own)

Hell, just list the colors of the bands on the resistor. That indicates its resistance


T


Bad Boys Rape Our Young Girls But Violet Gives(Gray) Willingly(White)


Thats how I remember the banding color code. (From high school)


Blue resistors or 1% tolerance (Usually)Edited by: mdhorban

MdHORBAN,

I was reading your original post again and I was thinking that your optical senor or Crank sensor could be causing the power loss/ check engine light.
What codes was the diagnostic giving? I have a laptop scantool that I ride around with, you need to use something like it to scan while driving for some real time sensor
watching.

Another thing you stated that your replacement driver failed to solve your problem. That really says to me the stalling/powerloss could well lie elsewhere.

MdHORBAN,

I was reading your original post again and I was thinking that your optical senor or Crank sensor could be causing the power loss/ check engine light.
What codes was the diagnostic giving? I have a laptop scantool that I ride around with, you need to use something like it to scan while driving for some real time sensor
watching.

Another thing you stated that your replacement driver failed to solve your problem. That really says to me the stalling/powerloss could well lie elsewhere.




Funny you said that. I just went to my bro's before I got online and he checked with his snap-on scope. I can't remember the code number but it was a crank sensor failure. He also checked the signal going into the PCM from the crank sensor and it was erratic. I got a new one coming in on Wed.(Bro gets a discount at his parts store) I was not able to check until now as my bro was off with his kid racing. I glad that you point out that this may be it. Find out Wed. Then I can check some signals with my ocilliscope from and to the PMD finally!