Engine/Transmission (1998.5 - 2002) 1999 2500 Cummins sputters on startup

[Madman]

I have a 1999 Dodge 2500 W/Cummins, about a week ago it "sputtered" on startup and ran like it was starving for fuel. I had 8 psi of fuel pressure at the time. I cut it off and it started up correctly. Saturday after, fixing a headlight problem, I tried to crank it and again it sputtered, this time 7 or 8 times before it finally started correctly and ran.

Changed the fuel filter, looked clean, drained the filter housing and found no water. All day it took several attempts before it would crank correctly. It seems as though something is getting an intermittent signal to send fuel.

I'm going to start looking at wiring diagrams. Any ideas?

 

[Madman]

May have found the problem.

I get code 1694 off the Cummins computer. The Chrysler computer gives no code.

When I put a circuit tester on the lift pump relay located on the firewall I get intermittent power, the light flashes very fast, when the engine is sputtering. Of course when it is running good I get a steady light.

I am afraid the Cummins computer has a problem, I cannot find a way to check the IP fuel relay, I think it is internal.

I am now searching for a Computer for my 1999 2500 manual trans.

 

[Road Dog]

I was under the impression that the lift pump was powered directly but the ECM -- no relay, no fuse, nothing. I was also under the impression that at startup the lift pump runs a few seconds and then cycles on and off until the engine starts. Too much pressure keep the injector pump from injecting. The VP-44 should work fine (except for overheating) with a non functioning lift pump. It's more for cooling the VP-44 than delivering fuel.

 

[hcole]

Road dog, I agree with you about the lift pump runs off of the ECM and there is NO relay OR fuse in the circuit for it. If there is a relay on the firewall, then someone has modified like I have mine. I have mine bring on the lift pump as soon as you turn on the key and the coil on the relay is powered by the power to the VP44. This is MUCH more reliable and keeps the lift pump from pulling the voltage down on the ECM.

 

[Madman]

I had heard that too. There is a "relay" on the drivers side fire wall that a friend of mine said to see if it was getting power on start up. When the truck cranks I get power all the way through start up, when it sputters I get a flashing intermediate light. I was waiting to see if I would get a call back from Cummins South before the end of the day but they didn't make it.

 

[Madman]

Road dog, I agree with you about the lift pump runs off of the ECM and there is NO relay OR fuse in the circuit for it. If there is a relay on the firewall, then someone has modified like I have mine. I have mine bring on the lift pump as soon as you turn on the key and the coil on the relay is powered by the power to the VP44. This is MUCH more reliable and keeps the lift pump from pulling the voltage down on the ECM.

Whatever it is came from the factory I am the original owner. I just checked both sides of the connection but did not open it up. I did run a hot wire to the LP to insure that is not the problem.

So if I am getting intermittent power to the LP does that indicate an ECM problem? I did finally get a 1694 code on the Cummins ECM.

 

[hcole]

I would think so as the lift pump is fed through the ECM and if that is intermittent then the ECM is at fault. I'd just take it off the ECM circuit.

 

[Road Dog]

The other thread brought up the Blue Chip Diesel VP-44 diagnostics. It's possible to hot wire the VP-44 so it will start and idle without an ECM. It's a good way to eliminate possible problems.

 

[Madman]

Thank you Road Dog. Great article, I am still trying to digest it.

 

[JR]

You can wire your lift pump independent of the ecm. Run a hot from the battery and into a relay that gets it's signal from a key-on accessory.

 

[Madman]

I did. that is what makes me believe the ECM is the problem. Even with full LP power the truck still sputters on start up sometimes. That is why I think the ECM is getting/giving bad info.

 

[Madman]

It is the ECM... I pulled one off a friends truck and everything works fine. Even back to 110 PSI of fuel pressure. Now I have to find one. I just left Cummins South. Chrysler bought the software and you have to go through them. Anyone know of a place to get one?

 

[Madman]

I meant back to say 10 psi at the gauge.

 

[Madman]

Found one in Miami. They check 'em before shipping. Should be plug and play. Thanks for the help.

 

[JR]

Well there are places where you can buy used but I have seen so many people have problems with them I would never go that route...

This is a decent place to buy from, good reputation, and the lifetime warranty can't be beat. Worth the few extra bucks over the lower end reman jobs that only offer a one or two year warranty. You can also send yours in for r&r to save a few bucks if your not in a big hurry. Just make sure to ask about the warranty if you go that route because I'm not positive they will give the same lifetime warranty as they do if you simply send yours in for a core and take one of their remans. The wording is a little confusing to better to ask before you buy.

http://goecmdiesel.com/product19__cummins_isx_isb-ecm_isb.html.

 

[Madman]

thanks for the info.