Hi excuse me to disturb you, I have a 98,5 dodge ram 2500 cummins. I ve just changed my vp44 by a rebuilt, I ve changed too injector by rebuilt 75 HP, changed the 6 lines by New, 6 connectors tubes seals, the fuel filter, put transparent hose to see if there is bubbles but no, and I have a problem. The truck start good, the idle doesnt move ( like apps dead), when I accelerate the engine cut off. I restart , it restart good. Before I forget I have installed before I changed all that, a superchips cortex programmer.... I found à little leak on my new injection lines ( 1, 3 4 5) at the connection with tubes... I have no code ... I make a video to explain it... what do you think it could be.... the little leaks? The programmer? The injectors? Thank you for your help

Mopar1973Man - Note

Attention: Our new member is from overseas and their native language is French. He's using a translator app from Google. Please be clear and explain your ideas well.

Mopar1973Man - In this video he's asking about the tach dipping down but it doesn't stall.

That is strange I have no code..... I have some little leaks between the end of the injection lines, I thinked it was this produce air which go inside by here and less pressure .... but I dont understand....

This happens when the idle speed drops, sometimes it cuts the engine and sometimes not at all....

Excuse me to disturb you but I live at Monaco, and in my country there is nobody to repair this truck. I ve just changed the vp44 I bought at Rockauto.com, because these are the only who ship in my country and with less taxes.... So maybe I missed something when reinstalling everything.... but I dont think... only when I install the injector lines to the connector tubes.... it was difficult to reposition them.... so thank you very much for your help.....

Mopar1973Man - You'll see the engine stall easily... What is the cause?

Edited May 5May 5 by Mopar1973Man

Do you think is it possible to test tps sensor and wires with a multimeter ?

Possible tight torque converter in the transmission?

I m going to change the tps, i ve just receive it and I will see..... that the first time it do that. Before to change every thing (vp44, injectors,....)there was no problem.....

7 hours ago, jeremyf9806 said:

Before to change every thing (vp44, injectors,....)there was no problem....

Don't focus on this. You could be right, but you also could be wrong.

Another scenario (mentioned by @Mopar1973Man ) that could cause your issue is a low stall speed transmission torque converter. Larger injectors allow much more fuel to flow, so when the engine comes to idle, the ECM has to cut way back on fuel delivery (not so much with stock injectors). So, things like a low stall speed converter, or engaging the clutch with a manual transmission, can cause idle fluctuations while the ECM tries to correct.

• John

OK. But I put new oem injectors. These are originals not modified. I think too at the ecm . But there would be normally a dtc if there is a problem with it. I dont know if it s possible to test ecm without scanner.

I will see friday. I will make an other vidéo too.

Thank you for your help again.

7 minutes ago, jeremyf9806 said:

OK. But I put new oem injectors

Ok, I understand. That should rule out a torque converter issue. It does make sense that something changed during the replacement of parts.

If I recall, you have to move the throttle assembly to the side in order to access all of the injector lines. Is it possible that the throttle is binding and not letting the throttle fully return?

If the throttle does not fully return every time, it is possible that the idle validation switch is not activated in the APPS circuit. It must be activated for the ECM to know to take over idling the engine. Engine idle is controlled by the ECM only - no other inputs.

• John

Remember Bosch stock injectors are NOT made as a set. You could have low end of 293 bar you the high end of 327 bar. This can affect idle performance. I high suggest AGAINST using stock injectors. Buy +50 HP from any good injector shop and they are balanced as a set within 2% of flow rate. Like my custom 7 x 0.010 is popped at 320 bar and custom tuned by the Quadzilla.

Remember low pop will advance timing, high pop will retard timing.

Friday I m going to replace the apps. And I will see.

When I pull the vp44, I decided to change the cam sensor, the tappet cover gasket too, and I must unpluged the ecm and I ve cleaned the connector and pins of the ecm with electrical product.

Do you think a wire of ecm could be disconnected when I reinstalled it. And how do I test it without scanner ? I need to tell I ve no trouble code..... it s really strange or maybe my obd tool can t read some code ....

Basic wire test is to ohm from end to end (unplugged) you should see less than 5 ohms for good wire. Above 5 ohms there is a problem.

Another test. Still both ends unplugged then measure connector pin to ground. This should show OL or infinite resistance. This means no wire shorted to ground. If any ohms show then it could have a rubbed jacket or wire damage. Remember both ends need to be unplugged or unhooked.

Also, unplug the ECM and check for any pins that may be pushed back.

• John

OK thank you very much.

Could you tell me wich wires at the ecm May I test . Because I remember when I unplugged it , there are so many wires ....

I don't know if I should leave the connector in its position to find the numbers, or if I should turn the connector over? Then I don't know which wires I should test. Should I disconnect the 2 batteries to do these tests? These may be stupid questions, but when you don't know, when you're going on an adventure, it's better to ask before blowing everything up. Thank you very much for these clarifications.

I remember it s a connector with 50 pins, but the job is really big !

When you talk about ohm test, is it really a continuity test?

I remember only cleaning the ECM connector and its plug with an electronics cleaner. I didn't disconnect anything from it. It wasn't dirty, but since I'm a bit of a neat freak, I like to have clean connectors. Also, when removing the VP44, I had to remove the apps block and push it near the hydraulic booster. I disconnected the apps sensor so I could put it to the side. That's all.

Shown below are the pinouts for the ECM. Perform continuity tests (using the ohmmeter setting) on circuits that you wish to check. Be sure there is NO POWER supplied to any circuit being tested. For example, the APPS communicates only with the ECM. You could perform continuity tests on all of the connecting wires (see bottom photo).

• John

OK. Thank you very much.

The photo of the ECM connector with the 50 ways is the photo of the connector as it is on the ECM from the front, wire side, or is it the photo of the connector turned inside out?

I'm talking about the first little photo on the left.

33 minutes ago, jeremyf9806 said:

The photo of the ECM connector with the 50 ways is the photo of the connector as it is on the ECM from the front, wire side, or is it the photo of the connector turned inside out?

That's always a bit confusing to me, as well. I verify by identifying some of the wire colors on the wire connector side to match them with the pin number. This will confirm the orientation for identifying the correct pin number.

• John

The little problem for me, Is this the right wire color for my 98.5 Dodge? Because I imagine that as time goes on they deliberately change the color and number... why make it simple when you can make it complicated...😁😁😁

The VP44 trucks were only made from '98.5 - '02. There could be a discrepancy in some wiring colors, but not likely.

Just pick a row that looks like the colors match the pinout row and you will know right away whether or not you are on track.

For example, if the LB/BK wire APPS signal from the ECM pin #25 was a different color than the diagram, then the wire will be the same color where it connects to pin #3 on APPS connector.

Just be patient - it will begin to make sense.

• John

Edited 18 hours ago18 hr by Tractorman

OK. Thank you very much

On the diagram sensor"signal" or sensor "supply" is it a positive wire ( + 5 volt)?Because I imagine there is no 12v on ecm or only at pin 48 and 50 it s write fused B+ .

Yes sir. +5V is supply, signal is the returning result of the APPS sensor. Then of course ground is 5V ground on the sensor. Beware the sensor ground is NOT body ground.