what did I MISS?
 

well after putting together the mystery truck with a 01 cummins with a VP that was "replaced" or "rebuilt" 10-20K ago and fed by a fass all its life I have developed a miss at idle and when lugging theres the odd part when turning on my fans (pull 60 amps each at start up and level off at 30 amps) the miss gets BETTER????

I have taped the ECM to only run off 5 wires and it works great I am thinking maybe being the ECM is wired in full time hot to the batt it may be getting to much voltage?

I was told running the 1st gen alternator could be throwing off the TPS but I have canceled that one out

I cannot plug into it due to there is no OBD2 port


its not bad not even enough to shake the truck just kinda there I can here it in the cab and in the exhaust real faint and random

any ideas?

if the ECM is wired in full time and running full time, then its probably causing a MAP sensor malfunction or misread. I had this happen when my ECM failed, it stayed on all the time and was dumping incorrect amounts of fuel due to thinking the MAP sensor was seeing boost when it wasnt.

I know the problem, its a vp.... :tttt:

so true ^^

Well, It sounds like a 5 volt problem in the ecm or FICM. Give me a minute and I'll pull up throttle schematics for the VP FICM and maybe we can figure out a way to signal the pump without the ECM at all.

You say the ECM only has 5 wires hooked up but if your going to use the factory apps thats not going to work. There's no way the sensor can reference and engine speed to build a idea of desired and actual rpm. So there is one problem.
For the throttle circuit / pump circuits to work correctly we actually need the following (not sayin it ISNT working, Saying it couldnt work correctly without the following and 99% positive it's relating to your misfire)
Pin number ECM
1 Idle Validation
10 5V Supply CKP
13 Datalink IP + 5v
16 Idle Validation #2
18 IP Sync Signal
23 IP Data Link -
25 Apps Sensor Signal Wire
31 Apps Supply (should be no higher that 5V
32 Apps Ground
33 Fuel Kill IP
34 Low Idle IP (uses pathwork with Idle validation)
44 IP Shielded Data Link
48 Fused b+
49 Ground

You'll also need
45 CKP Sig
11 CKP Ground


Heres the pump side
pin 1 bus - Required for variable throttle control
2 bus + Required for Variable Throttle Control
4 low idle select Required to Idle lol
5 fuel shut off Required to shut the truck off
6 ground Duh,, Must have lol
7 12v supply must have
8 fuel sync supply Required for Throttle Control

Again, Not saying it's not working ,Just saying according to all data, the computers method of operation, voltage routing within the ECM, and all other components these wires MUST be hooked up for throttle control to work properly, plain and simple.

thats 16 wires lol Just 11 More dont worry its not too bad!:tu:

Also forgot to include the fact that without the correct hot wires and ground wires in the ECM it will "draw" voltage, some what like life support. If it draws to much voltage the VP-44 with start misfiring as well!

What wires are hooked up now? Have you tested the pump stand alone to verify it runs smoothly with the ECM out of the picture? Really all a VP needs is a Hot and Ground, Throttle control can be another issue but in regards to VP the truck really dosent do anything. If it still misses in standalone you know for a fact it's the VP if it dosent its bound to be ecm related / voltage related.
Injectors popped correctly?
Didnt mean to go off on a wild tangent in regards to 5 wires on ecm, Just love wiring and computer issues lol

vp44 CAN message - Dodge Diesel - Diesel Truck Resource Forums

Just a note when I talk of signaling the vp, I'm not talking about throttle and fueling control only running the pump, had a couple questions on that. Without some type of standalone controller that could transmit data via can bus you couldn't provide needed information to the pump. Which as you see above is indicated by saying the wires are required.

Glad your back WOW!:jump: Good info.:c:

sorry but you got me wrong on the 5 wire deal

the whole engine wireing harness is 100% in-tack but I have tapped the harness and used a relay with ECM hot, Ground, and 12V power key on

just like this says to do

VP WIRING

There are 2 engine harnesses, one with a single body plug and one that has 2.

The VP has independent power that needs to be supplied by a simple relay. Theses relays have 4 posts (some have 5, if so disregard post 87a)

Post 30______constant hot

Post 86______brown and white from the engine harness

Post 85______ground

Post 87______Red/white or Red green from the engine


2 plug body harness


Plug with white lever:

VP44 relay control_________brown/white tracer_____________relay post 86

VP44 power______________Red/green tracer______________ relay post 87

ECM power______________Large red/white tracer___________Constant hot

Key on ECM______________light green/black tracer_________ignition wire key hot

Black plug

ECM and sensor grounds________Black/ brown tracer________GROUND

Grid heater________yellow/black tracer and orange/black tracer_____small posts on dodge heater solenoids




00-02 engines need to retain the WHITE/ORANE wire from the harness. This gives a speed signal to the ECM so it will fuel.

Lol I looked at that taped over and over thinking does he mean electrical taped or tapped lol with that out of the way, what about the pump in standalone? Is the wiring sufficient for 30+ amps? The pump pulls quite a bit, if it can't get what it needs it will cause a bit of a miss but with it wired like that your setup just like it would have been of course if your wiring is the correct gauges. With that said reducing voltages or creating a high amp draw could only impede the correct operation of data transfer across can bus. You still have a datalink don't you? I think you can run inline 5 on it. It should show you the miss!

1. no never pulled it off

2. yes its #8 hooked direct to the bat terminal

3. correct like said the wire to the fan's solenoid is hooked RIGHT next to the ECM wire on the batt cable and it pulls 120-180 amps on start and 60-100 continuous

4. as in the 3 prong plug that my edge EZ is hooked into? the plug that only cummins can plug into got $101.00 per hr lol

5.what ya mean?

1, You dont have to pull the pump off for standalone, the pump will run then engine without the ecm to verify the miss is with the pump or with the ECM Side. Eliminating everything but the vp-44 from the equation. You can do it with a couple jumper wires but I suggest the controller, we use it on a daily basis and it makes life a lot easier. I've got a couple i need to go through. If you need one, and I've got an extra we'll work something out.

2:Just because it's wired directly to the battery doesn't mean it's sufficient for 30+ amps. It's in the wiring too, What gauge wire? You do have a fuse link in it correct? The VP Power Wires must be atleast a 10 gauge at no longer than 8 feet that will keep you at 5% loss or below. Copper wire

3:Impede : Verb- to restrict or retard in action, progress, etc.; hinder; obstruct.
This may be a fluke that it's helping. It really shouldnt. The pump wont "draw" more amperage than it needs and the pin 7 is a 12v, then entire pump is 12v (unless it switches deep inside) so regardless of the fact it's hooked to the battery, any reduced power will effect the pump in a negative way.

4. Yep, that 3 prong pin, the number 5 refers too, And we can hook to it too! I figured you had inline 5, The cummins program. There's alot of small shops that have it, if you can find one, you can really figure this out in minutes . Cummins Inline 5

cummins inline 5 items - Get great deals on Parts Accessories items on eBay Motors!

Finding the correct adapter for these trucks (dodge dealers will sometimes have a miller plug that came with DRBIII that will plug in) can be a pain but I promise inline 5 will read it.

I should have explained in my original post, DATA LINK = Data from and too the Ecm...Doh..... Inline 5 = Software to read data link data, converter for converting can bus data to usb, serial (hopefully captin crunch), etc etc etc lol also includes the needed abilitys to write the ecm. I vote this is where all the "tuning" started out at, I'm sure the big dogs are using another type of interface now, but I vote it all started here.

From looking at it the ecm absorbs some of the noise from the electrical system or suppresses it which means it would "regulate" the hot to the vp. You could try a noise filter as well. It might help. The ECM in 98.5 Up trucks to 2002 is wired to a ASD Relay, Auto Shutdown Relay and the truck should be wired in a similar fashion. Is your ECM Wired Key on only on the relay? Not all ECM's powered off with the ASD, but I was figuring this whole time you had a battery disconnect or unhooked the cables and left a KAM wire connected? If thats not the case thats probably a good place to start too!