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Number 9 resistor vs number 5

B

bdemutis

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So the other day I noticed that my pmd didn't have a resistor in it and it was still in the old one well I took the resistor out and put it in my new pmd. Well I noticed the truck seems to run and start smoother and that startup smoke clears up faster or that the 2 stroke I've been adding anyway. I was wondering what is the advantage of a number 9 resistor I have the stock number 5 resistor in my truck now will there be any benefit to putting a number 9 in there?
 
You will not notice the small change the resisters make. Get a tune and that WILL make a difference.
 
WarWagon said:
You will not notice the small change the resisters make. Get a tune and that WILL make a difference.
Click to expand...
Is there any one that flashes 95 chips that I cab buy a chip and send it out to get flashed?
Also just looked at my service receipts I got with the truck all 8 injectors were replaced in may of 2011.
 
Last edited:
bdemutis said:
Is there any one that flashes 95 chips that I cab buy a chip and send it out to get flashed?
Also just looked at my service receipts I got with the truck all 8 injectors were replaced in may of 2011.
Click to expand...
Check with leroydiesel, he has contacts who burn tunes.
 
Its a misconception that #9 will give better perf than #8-3. They were used to calibrate the IPs on the bench. Also the only time the ECM see's the resistor is at WOT only. IF! in theory the #9 would flow more fuel you would never know the diff compared to a #5.
As a result I only stock the #9.
http://leroydiesel.com/products/9-resistor-for-pmds/

I can also get you a new tuned Eprom for 94-95.
 
Burning oil said:
Its a misconception that #9 will give better perf than #8-3. They were used to calibrate the IPs on the bench. Also the only time the ECM see's the resistor is at WOT only. IF! in theory the #9 would flow more fuel you would never know the diff compared to a #5.
As a result I only stock the #9.
http://leroydiesel.com/products/9-resistor-for-pmds/

I can also get you a new tuned Eprom for 94-95.
Click to expand...
Leroy, has KOJO tune been developed for the HX40w yet, or?
 
Burning oil said:
Its a misconception that #9 will give better perf than #8-3. They were used to calibrate the IPs on the bench. Also the only time the ECM see's the resistor is at WOT only. IF! in theory the #9 would flow more fuel you would never know the diff compared to a #5.
Click to expand...

smileys-applause-459840.gif
 
Actually the ECM only "reads" the Resistor value every 50 starts, setting the timing, or battery disconnect. Otherwise it's a stored value allowing a PMD swap to miss moving the resistor for months till a code and SES light pops up.

Injector miles, not age, matter. How many miles are on the injectors - you may need to cross the date to an oil change note.
 
WarWagon said:
Actually the ECM only "reads" the Resistor value every 50 starts, setting the timing, or battery disconnect. Otherwise it's a stored value allowing a PMD swap to miss moving the resistor for months till a code and SES light pops up.

Injector miles, not age, matter. How many miles are on the injectors - you may need to cross the date to an oil change note.
Click to expand...
Well the only mileage records I could find was 8/1/13 had 194k on it so I'm guessing if the injectors were done in 2011 that they might have just reached 100k on them or didn't even hit 100k yet.
 
WarWagon said:
Actually the ECM only "reads" the Resistor value every 50 starts, setting the timing, or battery disconnect. Otherwise it's a stored value allowing a PMD swap to miss moving the resistor for months till a code and SES light pops up.

Injector miles, not age, matter. How many miles are on the injectors - you may need to cross the date to an oil change note.
Click to expand...
This is true also, thanks.

Thanks GW! I got two smiley's from you!
 
Burning oil said:
Its a misconception that #9 will give better perf than #8-3. They were used to calibrate the IPs on the bench. Also the only time the ECM see's the resistor is at WOT only. IF! in theory the #9 would flow more fuel you would never know the diff compared to a #5.
As a result I only stock the #9.
http://leroydiesel.com/products/9-resistor-for-pmds/

I can also get you a new tuned Eprom for 94-95.
Click to expand...

Have any data to back this one up? The tunes actually show the value is only respected under 1800 RPM which is why I ask.

Granted it's still no performance gain, I just don't know where the WOT statement comes from
 
As for me no, I thought it was just common knowledge. Ive been told by different tuners that are way smarter than me the same thing. Maybe GW can input?
 
There was a STANADYNE chart posted over at DP MANY moons ago, and I believe it said putting a #9 into a pump that called for a #5 would yiled you roughly 69MM3 of fuel at WOT VS the 64 the ECM normally commands. It is wierd the breakpoints of what each resistor does, some change the total fuel output a .5MM3 of fuel, while others jump almost 2MM3 of fuel. The value is only changed when the ECM does a TDCO relearn every 50 engine cycles(meaning you cold start it, and run it until it reaches at least 170 degrees) hence why running without one can allow some trucks to run for MANY months before they code for it, while others will code almost immediately. It all comes down to where at t0eh ECM was with it's engine cycle counter and when the resistor is changed/removed.
 
I thought I remembered that the 50 starts was for OBD1 and OBD2 didn't need a resistor after TDCO was performed
 
ak diesel driver said:
I thought I remembered that the 50 starts was for OBD1 and OBD2 didn't need a resistor after TDCO was performed
Click to expand...
They ALL update every so many starts. It has been argued that OBD2 doesn't update the resistor value, but then there is posts of OBD2 trucks running like crap out of the blue just to find out it updated the resistor value, and without one it went to a 1.
 
I have seen the aftermath of a Suburban engine that ran without a resistor! :eek:


:D Seriously After rebuilding the blown engine it finally coded that the resistor was missing from a pump mounted PMD. The PO never noticed it missing before the engine blew up.
 
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