Engine/Transmission (1998.5 - 2002) Dead On The Highway

[Greenleaf]

Hi Guys,

Had some tough luck with a new bus of ours. Dead on the highway. Had to tow. My first time. Got razzed pretty good by the staff and former bus mechanic for towing. Towing costs $$$$ and the school DON'T like it. What else was I to do. It just stopped with out warning. Looked it over and everything looked ok.



Back at the bus barn I called the dealer and was told of this real cool method to test out a VP44 wire harness. You simply install a headlamp in the circuit. If it lights everything back of the VP44 is good. My light lit. VP is toast.



Pretty scary to think that is all it takes to kill a Cummins. The bus that took it's place is a 1989 Bluebird with well over 10,000 hrs on the VE pump.



Hail ye 'ol VE.



Sorry, not trying to make enemies, but there is a lot to say for a mechanical pump. I have nine ISB's here,,,,YIKES!!!!!!!!!!!!!!!!!

At least it's under warranty.



I like the sound of the ISB and don't mind saying I'd like to have one of my own, 'cept now I'm thinking twice. Stranded on the road 'cause my pump went south don't look good for Cummins.

Scott

 

[Gary - K7GLD]

Would ya have felt BETTER if it was stranded by a blown tire - or headgasket? There are MANY potential failure points on ANY vehicle - old OR new design - shoeleather is shoeleather, and WALKING away from a mid 90's vehicle is no more fun than walking away from a newer one...



BUT, the time spent behind the WHEEL of the newer ones is sure lots more fun!



*I* respect the known weaknesses of my '02 - just as I did the ones in my '91 - but I took steps to minimize those weakness on BOTH vehicles, and dern sure WOULD NOT live in fear of actually USING them!

 

[B.G. Smith]

Well don't feel bad, it happens to the best, er maybe I should say the worst (pumps). Lots of VP still running with over 100,000 miles though. I doubt that the test (headlight in VP circuit) is that simple, maybe a special wiring harness to plug in as the circuit to the VP has several wires. Then again, maybe the dealer had all his mechanics sitting around and your bus was the plum. Hope not but stranger things have happened. I'm keeping mine.

bg

 

[Greenleaf]

Lamp Test;

Insert test leads into the harness plug at the VP. (Remove it first!) Then connect the leads to a lamp. Turn key on. If the circuit pulls the load, you have a faulty pump. This test is per the Cummins service bulletin. Hope this helps. I can post the bulletin no. if needed. This test will confirm several items downstream of the VP.



Scott

 

[Greenleaf]

Forgot to mention;

Pin #7 is power.

Pin #6 is ground.

The light dosn't care which is which. You can test for power with a DVOM at #7 with key on AND cranking.



This is the Cummins wire harness. NOT a Bluebird bus harness, so it should be the same on any ISB.



-S

 

[Gary - K7GLD]

There's another test as well, that shorts out some pins on the VP-44, and then if the truck will start and idle, the pump is OK - I forget the exact details, but a search would bring it up...

 

[Gary - K7GLD]

Here's a pointer to the thread on testing the VP-44:



https://www.turbodieselregister.com/forums/showthread.php?s=&threadid=74018&highlight=VP44+test



I have also brought that thread up to the top of the forum for new members who might not know about it...