Results 1 to 18 of 18

Thread: Which Resistor to use? Or No Resistor at all?

Hybrid View

Previous Post Previous Post   Next Post Next Post
  1. #1
    Join Date
    Feb 2017
    Location
    Jonesboro, GA, USA
    Posts
    9

    Default Which Resistor to use? Or No Resistor at all?

    I did a search for this and came up with nothing. Searching "resistor" found too many to search through.

    Which resistor should be used in the PMD/FSD? I've seen #5 and #9's
    What's the difference?
    Can you run without one at all?

    Getting the old resistor out is a booger. I'm thinking that if mine dies on the road (I have a spare), can I run the new one without a resistor if I am unable to get the old resistor out at the time?

    Should I purchase a new resistor? if so which one and why?

  2. #2
    Join Date
    Dec 2003
    Location
    Yukon Canada
    Posts
    1,612

    Default

    Hi
    Getting the resistor out is easy with the right tool.
    There is a hole in the resistor that you can hook with a wire with a 90 bend near the end.
    I believe that the #5 is a happy medium.And yes you need the resistor.
    90 Chev 3500 c/c 4x4,6.2na,400 auto,4:10 gears.DSG Timing gears,main girdle, isspro tach, pyro,boost,oil and trany temp.Dual Tstats, High volume peninsular pump,on shelf, Custom turbo and intercooler 85%complete. Change of plans for the dually, it's going to get a Cummins. Both trucks are Blue 90 4x4 crews

  3. #3
    Join Date
    Jan 2001
    Location
    New Hampshire - Live Free or Die
    Posts
    6,057

    Default

    IIRC there are two holes in the resistor. A paper clip bent into a "U" shape with a tiny hook at a right angle on each end will pull it out.

    The resistor tells the ECM the pump's calibration. The value is stored in the ECM. Usually, the ECM won't notice if the resistor is missing. Only when it decides to read the value will it complain. If it can't read the resistor it will default to the lowest fuel map.

    The right resistor for your new PMD is the same as the one that came with the pump when it was last calibrated. This should be the one in there now, unless someone in the past changed it.

    Using a higher number than spec will increase the fuel rate slightly, if you also force the ECM to read the new value. The easiest way to accomplish this is to force a TDC offset learn cycle. However, if you go too far from the correct value the throttle will get touchy and the engine may surge. I had a pump that called for a #4 and when I tried a #9 it was beyond annoying. I want back to a #4, although a #6 probably would have been fine. The power increase is small, though.

    So, bottom line, if you have no resistor, you should be fine for a while, and even if it is detected, it will still get you home. To avoid problems all together, either dig the resistor out of the old PMD (easy if you have a remote mount) or get a new one of the same value. If it is not remote mounted, or you can't get to it, you can always read the value stored in the ECM with a Tech II.
    The Constitution needs to be re-read, not re-written!

    If you can't handle Dr. Seuss, how will you handle real life?

    Current oil burners: MB GLK250 BlueTEC, John Deere X758
    New ride: MB GLS450 - most stately
    Gone but not forgotten: '87 F350 7.3, '93 C2500 6.5, '95 K2500 6.5, '06 K2500HD 6.6, '90 MB 350SDL, Kubota 7510

  4. #4
    Join Date
    Apr 2001
    Location
    Newberg Oregon
    Posts
    12,282

    Default

    If you have the old PMD off the rig you can look into the plug socket on the PMD and see the tiny circuit board that the resistor is on..

    The will be a number from 1 through 9 on the little circuit board.

    I sacrificed a small screwdriver to make a tiny hook that can be inserted into one of the outer holes in the resistor board and lifted alternately from side to side and the resistors come right out.

    Do not be tempted to use a #9 (Unless that is what yours had originally) as the computer will usually scream after it finds it.
    (1) 1995 Suburban 2500 4x4
    (1) 1997 Astro
    (1) 2005 Suburban (Papa Smurf)
    THIS IS BOW TIE COUNTRY

  5. #5
    Join Date
    Feb 2000
    Location
    Montana
    Posts
    11,382

  6. #6
    Join Date
    Feb 2017
    Location
    Jonesboro, GA, USA
    Posts
    9

    Default

    You guys are great (assuming you are guys)

    Thank you, and as I read you comments I began to remember a little about this.

    I may find one online somewhere. PMD's don't go bad too often so I'll probably be good for a while. What happened was (wha' had happn' wus) I made an offer of $175 for a $200 DTech on ebay didn't think they would take it. I needed the truck over the weekend and just bought a Dorman from Oriely's.

    Sure 'nuff, they accepted my offer and I couldn't back out. Now I have an extra PMD.

    Sleep well everyone, be good and have fun!

  7. #7
    Join Date
    Nov 2002
    Location
    Martinsville, IN
    Posts
    3,163

    Default

    Quote Originally Posted by Robyn View Post
    Do not be tempted to use a #9 (Unless that is what yours had originally) as the computer will usually scream after it finds it.
    This isn't true in my experience with several trucks.

  8. #8
    Join Date
    Apr 2001
    Location
    Newberg Oregon
    Posts
    12,282

    Default

    I have tried the #9 in a few, and depending on the original resistor that was used issues came up.

    Seems that if the original was greater than #5 it would likely not complain.

    If the resistor was on the lower end of the scale a complaint was more likely.

    I used a #9 in my Dahooooley, but it had been chipped and the new programming did not care, and it was probably designed to use the 9.
    (1) 1995 Suburban 2500 4x4
    (1) 1997 Astro
    (1) 2005 Suburban (Papa Smurf)
    THIS IS BOW TIE COUNTRY

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •