Engine/Transmission (1998.5 - 2002) Cummins Dealership can NOT fix it.

[Greenleaf]

I'm not the best mechanic a'round but I do OK



A 1999 Cummins "ISB" in one of my buses. I have wrenched for months and drove it (very slowly) to the local Dealership. They wrenched on it for three weeks solid and threw in the towel :-laf They replaced some of the same parts I have, and charged me for it.



The engine will not run above a slow idle. Misses/spits and sputters. No engine code(s) so I started to replace parts. Even has great supply pressure to the new VP-44 injection pump cuz I changed all the filters and installed a new lift pump.



I replaced several sensors and the engine computer. Replaced injectors too and injection lines. Adjusted valves. Performed a load test on the lift pump and injection pump electrical system. The Cummins Insite gives no indication of a problem. The engine runs the same when supplied w/fuel from a bucket.



It don't look good, does it?



Scott

 

[Gary - K7GLD]

Seems to pretty much narrow it down to VP-44, APPS, or something else... :-laf:-laf



Dunno if that application provides the same error/code info as our dodges do, but odd that no codes are set...

 

[Greenleaf]

Same codes for the engine, but I don't know about the powertrain.



I have the Cummins plastic covered code book. It has a list of seemingly endless codes. There is a code for everything, even if the engine sneezes.



I have no codes on the dash display, nor does the insite program show any.



I too believe it to be the injection pump. It has had three of them though...

 

[Bob4x4]

Do you know if Cummins tryed running it with a hot box on it ?



Bob

 

[Joseph Donnelly]

You can eliminate the engine control module (ecm) and accelerator pedal position sensor (APPS) from the equation with the Cummins test box that plugs into the wiring harness connector of the VP44 injection pump. It will enable you to start the engine, and has a setting to take rpm up. If the engine is OK with the test box, your ecm or APPS is at fault. If not, replace the VP44.

 

[NIsaacs]

Did you check the fuel return line to the tank? It might be plugged up?





"NICK"

 

[Mhannink]

Did you check the fuel return line to the tank? It might be plugged up?





"NICK"

he said it runs the same on a bucket or from the tank.





i would be looking at the same and see if its timed right.

 

[obert]

he said it runs the same on a bucket or from the tank.

were both hoses in the bucket???



add/edit: Where would the "plug" come from in the return? Inj. o-ring would show elsewere, and Scott would've caught that on the inj. change...

 

[NIsaacs]

It sounds like GL and Cummins has/did just about everything "normal" to find the problem. I am trying to think of abnormal trouble shooting.



As far as the fuel return line being plugged How/why does any line get plugged? Maybe a bug crawled in the line when it was unhooked or someone kinked the line with a jack while working on the chassis or somehow a chain pinched it or the short rubber piece from the frame to the engine has deteriorated and swelled shut????????





"NICK"

 

[Greenleaf]

I towed it (560. 00 ) to Lima Ohio and the shop forman said it sounds to be a faulty boost signal (sensor) Maybe so... ... ... ... They will know more later.

 

[LMcCary]

Please list all of the sensors that have been changed. A boost sensor or faulty crank sensor will do this.

 

[Bob4x4]

Please list all of the sensors that have been changed. A boost sensor or faulty crank sensor will do this.

I have never had a boost sensor failure do anything like that

I still havent heard if a hot box had been tryed yet.



Bob

 

[DBraunig]

Greenleaf,



I have the Cummins test box if you need to use it. We might be to far away from each other. I'm near Lexington, KY.



Dave

 

[Greenleaf]

Please list all of the sensors that have been changed. A boost sensor or faulty crank sensor will do this.

I changed the cam sensor, crank sensor and charge air temp. sensor. I was told by the dealership not to change the sensors as it is a waste of time, so I didn't change the boost signal/ sensor.



I have had boost sensors go out and the bus acts very much the same. However, the engine lamp(s) ALWAYS come on and insite will tell you "boost signal out of specs" It is an active code.



I don't know what a Cummins Test Box is nor a "hot box" I don't have much in terms of test equipment. There are only 9 ISB's here so the school doesn't feel the need to buy test equipment. I have to pay the Cummins dealer to drive over to the bus garage with the Insite program to pull codes from the computer in order to troubleshoot these units.



I have a DVOM and 16 psi fuel pressure guage.

 

[B.G. Smith]

This is an old thread about testing the VP-44. bg https://www.turbodieselregister.com...nsmission-1998-5-2002/74018-testing-vp44.html

 

[Gary - K7GLD]

My MAP sensor was intermittent - ran with reduced power and boost PSI due to less fuel, but NO other symptoms (other than a P0237 error code), and was entirely driveable - so can't see how all those other poor engine performance issues could be MAP related...

 

[Bob4x4]

I

I don't know what a Cummins Test Box is nor a "hot box" I don't have much in terms of test equipment. There are only 9 ISB's here so the school doesn't feel the need to buy test equipment.

.

Ok here you go ... ..... picture is worth a thousand words



#ad




This is the hot box as we call it or test box as Joe calls it. It supplies the vp44 with the electrical it needs to idle and fast idle,eliminating all the vehicle sensors and powers and grounds from being used to run the engine. You can do the same thing with clips but the pins are so small it is easy to make a mistake and fry the pump.



Bob

 

[RJWEST]

Bob4x4, what does this box cost,?
AND, anyone have a schematic for it... .

 

[MMiller]

This is totally off the wall, and probably does not apply, but I'll throw in something... I had a 3208 totally confuse me and all of the old Cat mechanics a year ago. It would start fine, white smoke like crazy and have a dead miss at anything over low idle. I fought everything in the fuel system, fuel lines, filters, adjusted valves, checked timing, everything. No change... Pulled the air filters for some reason, and started it with out the filters and it ran like a top, no smoke and smooth as silk. Install the air filters and the dead miss, low power and white smoke were back. Then the customer remembered that the exhaust had rotted off the fall before, and going through the field the normal exhaust fumes would get sucked into the air intake pipe. Upon further inspection of the air filters, they were gray colored from the soot plugging up the filter. No dust, no dirt like you would normally find in a tractor air filter, just a little gray.



Never before have I had an air filter fix a dead miss.



Michael

 

[Bob4x4]

Bob4x4, what does this box cost,?

AND, anyone have a schematic for it... .

I don't remember how much it cost,I got it back in 98 when I was still learning the 24v woes



Bob