upgraded ecm for the vp's!

Rpms are good but without the fuel cutoff turned "off" were still in the same boat. Just let it fuel 100% to 3200 and ill be ecstatic.
 
24VCummns98 said:
Rpms are good but without the fuel cutoff turned "off" were still in the same boat. Just let it fuel 100% to 3200 and ill be ecstatic.
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Exactly!!

The electronic limit in the VP44 FPCM will have to be removed!!!

once that is done...it's a no brainer...and a wire tap would no longer be needed...it would all be in the ECM
 
I'll let you guys know what I find when I get the ECU. What is the Jessup tune exactly?
 
Jim Jessup use to work and do tech writing for the 12 and 24v (98.5-02) cummins. Since the 24v cummins is 235/245 hp motors, im guessing that his tune will bring it up to the 275 rv 5.9's. Back when i last talked to him he would reprogram your ecm and max out some of the values. He would go through the data port on the drivers side. When we went to take it for a ride it only felt like 35 hp gain. Just a puff of smoke and about 3psi more boost. There were no more rpm's. Alot of people dont realize that when they turn there boxes on it overides his program. Atleast thats what he told me.

Some people say that he has been turning them up but i doubt it. He was always about reliability.
 
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vwmikel said:
I'll let you guys know what I find when I get the ECU. What is the Jessup tune exactly?
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Fed Ex Ground. Next week some time. Take your time on it, don't neglect your current customers sales on this. We are all just having fun...

Say Mike, where could I source one of those Audi V6 TDI FPCMs from?
 
FireMed said:
Jim Jessup use to work and do tech writing for the 12 and 24v (98.5-02) cummins. Since the 24v cummins is 235/245 hp motors, im guessing that his tune will bring it up to the 275 rv 5.9's. Back when i last talked to him he would reprogram your ecm and max out some of the values. He would go through the data port on the drivers side. When we went to take it for a ride it only felt like 35 hp gain. Just a puff of smoke and about 3psi more boost. There were no more rpm's. Alot of people dont realize that when they turn there boxes on it overides his program. Atleast thats what he told me.

Some people say that he has been turning them up but i doubt it. He was always about reliability.
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The VP37 pumps normally work by the ECU actuating a servo that moves the control collar like the governor would on a regular VE pump. A potentiometer on the servo provides a feedback signal to the ECU to determine the position of the quantity adjuster. Most tuning boxes for these exploit a simple voltage divider to dampen the feedback signal so that the ECU will increase voltage output to compensate. So, this does not really override the signal, but simply adds a percentage. The same torque curve remains, but is increased. This is the torque limiter from an EDC15 ECU (VW 1.9L TDI - ALH engine code):

torque_limiter.jpg


It is designed for peak fueling to coordinate with peak volumetric efficiency. Adding a percentage of fuel everywhere does not change the shape of the curve and adding 50% to an injection quantity of 0mg is still 0mg. So, the factory RPM limitation remains.

I'm not saying that this is how the Cummins boxes work, but it stands to reason that they would not replace, but rather modify the signals in some way. So, in that respect it doesn't really override the tune, but adds to it.

I should probably also note that in the case of this ECU (and most if not all others), the torque limiter is just one component used to determine the overall injection quantity. I only make mention of it as I think it is a good visual aid to the concept.

ThrottleJockey said:
Fed Ex Ground. Next week some time. Take your time on it, don't neglect your current customers sales on this. We are all just having fun...

Say Mike, where could I source one of those Audi V6 TDI FPCMs from?
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I'll see how it looks when it shows up and report back.

Audi V6 TDI's weren't sold in North America. The simplest place to find one of these ECU's would probably be on ebay.co.uk, ebay.de, etc.

It may be worth noting that the Audi ECU is designed to be a full engine management computer. In addition to controlling the pump, it also controls a VNT turbo, EGR, etc. One concern I have is how to get a crank sensor input. I'm not sure how the two compare.
 
I have a friend with a late 98 truck that will turn 4000 and all it has is 150s, an edge box and a Jessup tune. I know the last three owners of this truck. The first owner had Jim tune it. I called Jessup and asked him about it and he said he does not have a 4000rpm tune. I dont know why it turns 4000 but I have seen it first hand several times. Does anyone have a guess what the deal is with this truck?
 
Rumor is that some just do. I have heard and read about it on several other trucks.
 
I've tried numerous things to get more than 3200rpm. I've had numerous conversations with Chip @ Bluechip and I've tried a few different redline's. My truck refuse's to turn more than 3200. I'm very interested in more r's
 
Sweet, i just figured out this dang multi quote.......

01 smoke said:
I have a friend with a late 98 truck that will turn 4000 and all it has is 150s, an edge box and a Jessup tune. I know the last three owners of this truck. The first owner had Jim tune it. I called Jessup and asked him about it and he said he does not have a 4000rpm tune. I dont know why it turns 4000 but I have seen it first hand several times. Does anyone have a guess what the deal is with this truck?
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I have heard the same thing as roachie. There are just some that do it. No reason no ryme. I know that josh sold his truck with the ecm on it a couple years ago. I was hoping to catch him before that but it was gone.

Double J said:
If he's able to crack the code that so many have failed to do, I think it'll be well worth his time in the end.
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x2
 
That truck seems to run extermly well for what little is done to it.
 
Mike, iv got two ECM's from a 99 manual trans and an extra Standard Output VP if you might need more.
 
FireMed said:
Mike, iv got two ECM's from a 99 manual trans and an extra Standard Output VP if you might need more.
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In time it might be worth comparing the software between the different years (perhaps even one that turns to 4000?) and between manual and automatic transmissions. But, for now I need to work on establishing communications, basic understanding of the software, and checksum correction. So, I might take you up on that one (hopefully sooner rather than later).
 
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Does anyone know of a specific year or part number of ECU that revs to 4000? It might be a good place to look for clues.
 
Before selling my 2001 I did testing for Quadzilla on thier 4k tunes (still defueled) and tried every VP box and stack out there. Best I could get was 4030rpms with the redline and smarty on 1 for timing... but it wouldnt stay there just hit it and defuel. Best programming for smooth reliable power was HRVP with TST comp 9 and Smarty on 1.(3800 usable rpms)

Last year I decided to p-pump my truck. To make everything work seamlesly I tapped the fuel shut-off solenoid "hold" signal wire into the 12v hot from the VP harness. It worked great... that is until I started pulling over 4k RPMs. I found the lift pump circuit and VP 12v circuit were being disrupted by the cummins ECU sensing runaway!

Once I tapped a seperate 12v power supply (I called it my 4k switch!) into these two circuits it worked great. Would pull hard past 4k till I ran out of AIR from turbo limitations. Made me wonder what wouldve happened if I kept the VP and just tapped those circuits.

I dont think this will solve all the issues but I do think these would need to be addressed along with internal pump mods to reach 5k. I loved the driveability and quick spooling of my VP truck but all the extra fuel and RPMs from the P7100 was well worth the swap.
 
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