Hello,

I have been lurking for some time and now it's time to post. I am posting this in the 94-98 forum, my bus is a 1992 Bluebird TC2000 with 5.9 Cummins. However, it has a Bosch P7100 pump from the factory, hence why I am posting it in this forum.

The bus has 79,000 miles and was, to my knowledge, stock. Two weeks ago, I took the bus across the state to a friend's house who has converted a couple of buses to run off of waste veggie oil. My partner and I travel often for our work as musicians and are converting our bus. We finished the conversion on the second evening and started the bus up on diesel with some minor bleeding of the injector lines. Note, the bus has NEVER HAD VEGGIE OIL RUN IN THE ENGINE. With the valves switched in the current position, the entire fuel routing essentially same as stock.

While we were running the bus on diesel, we accidentally left the veggie oil filter off. Diesel backflushed down the line and diesel was pouring out of the filter head. We didn't notice this right away and lost a lot of fuel. I didn't have much more than 1/4 tank in the bus...not really sure. I put a filter on and we ran it for another 5 minutes or so, checking for leaks.

All of a sudden, it shut off, as if someone turned off the ignition. It has not started since. At the time, my thought was that we ran it out of fuel.

What has ensued has been sunup to sundown troubleshooting, nearly every day, towing the bus across the state (thank god for AAA), and more troubleshooting. I have taken the fuel system completely apart more times than I can count. My original thought was there was air in the lines. I have bled the lines with compressed air in the tank, hand priming, and putting an inline electric pump in the lines to no avail. We have bled injectors more times than we can count. I have returned lines to stock to no avail. I did everything I know (and learned) to do 5 times over... maybe more. We have run diesel straight out of a fuel can, verified all the routing of everything, and more...

-We have verified that the Fuel shutoff solenoid is working.
-We have swapped out to a Torx Tek OFV and it changed the starting fuel pressure significantly (from 0 to ~20psi)... still no start
-Because of pressure when cranking, it seems the lift pump is working properly, but we have not swapped it out.
-We have verified that fuel is getting to the injection pump and out of the return. Fuel is currently NOT getting to the injectors.


I am pulling my hair out with frustration. I am REALLY hoping we didn't somehow toast our injection pump. I am hoping there's something I missed, but I don't think there is. I have become to know my fuel system VERY intimately.

Any thoughts? Anything we have missed? Ideas for us?

We hired a mobile mechanic to come out from the local Cummins dealership/service center and $250 and an hour later, he basically said I tried everything that he would, he didn't want to waste anymore of our time and money, and that we would be best off to start looking at internals on the injection pump. Any ideas before we tow it into the local Bosch specialist? Any last minute things to check?

Any help is greatly appreciated.

Thanks,

Jeremy

 

While turning the engine over, crack injector lines, have foot to floor, this will deliver more fuel ....

Other wise, it may be the IP having some issues ??? Not real sure what could suddenly cause the issue though ....

how much fuel have you put in the tank since you started ... ?

 

I have tried it with the pedal to the floor and without.

I originally added ~10 gallons of diesel and have since added another 10, so 20 gallons since the original issue.

 

Almost sounds like a plunger is or could be stuck in IP ....

so with an injection line off does the IP squirt any fuel when turned over ??

 

the thing should have around 35psi of fuel pressure

did you run the injection pump completely out of fuel or did you notice the leak while the engine was running and then shut it off? if it dies from lack of fuel there is a big chance you messed some stuff up in the pump. they are cooled and lubricated partially by fuel.

have you wired the shut off solenoid up into the run position?

can you get it to start on brake clean? it may be air? maybe it need a little help burping, some blead super easy and some you have to fight.

if and when you get this figured out, I STRONGLY STRONGLY recommend converting absolutly everything back to run on diesel fuel. so many injectors and injection pumps die a sticky, gummy, leaky, poor spray pattern, horribly fuel milage, french fry smelling death, just because someone is out to save a dime, when in the real world once it breaks you are spending thousands more than what you saved in fuel just to make it run again. (personally)

 

No fuel... this is partially my thoughts and worries too.

 

35 psi when cranking? or running?

It will run on ether, but will not stay running on it's own. It will begin to spurt out a bit of fuel in this case.

We did not shut the engine off. I got the filter back on as soon as I noticed it was losing fuel, ran for a few more minutes, and then it shut off on its own, as if somebody turned off the key. I do fear that it ran completely dry and took out something inside the pump.

Thanks for your opinions on the WVO system. I have done well over a year of research and this is something we are committed to do... not to "just save a buck" either. We are artists, tinkerers, and are living in this bus as an experiment in our lives. We have our reasons. If everything blows up in sticky, gooey, veggie-ness, we still have our "home". We have weighed the possibilities. Our diesel fuel running out may have just cost us $2500+. It's not only WVO that costs money! For the sake of this thread going south, I would prefer not to discuss veggie oil in this thread. For all intents and purposes, at this time the bus has only been a diesel bus and we added a second tank, that could run diesel or veggie oil, and can be heated if we choose It has never run veggie oil.

Thanks for the tips on the diesel side of things. It is much appreciated.

 

[QUOTE=white99z;1065307]35 psi when cranking? or running?

It will run on ether, but will not stay running on it's own. It will begin to spurt out a bit of fuel in this case.

We did not shut the engine off. I got the filter back on as soon as I noticed it was losing fuel, ran for a few more minutes, and then it shut off on its own, as if somebody turned off the key. I do fear that it ran completely dry and took out something inside the pump.


running, but it should be 20+ cranking. regardless they will run on very very low fuel pressure.

if however it died from fuel starvation and with the problems you are now having you very well may have an IP problem. if it pops right off on starting fluid and has adiquite fuel pressure than it should very quickly work any air out of the pump and lines.

i must say one more thing on the veggie oil thing. run 2 tanks and periodically run a full tank of diesel fuel with some good additive through, to de funk the system. so many times ive seen really nasty injection pumps that have met their demise from used oils.

 

one more thought is to crack the OFV a half turn and then crank the engine over. do you get 20psi of fuel spraying all over everything or is there possibly a blockage that broke loose when the filter was dangling?

i dont know where you are located but it takes about 1 hour to pull the pump and cost approx $400 to have a facility run it on the stand. if it needs overhauled most places wave the labor of running it for the business of the rebuild. a standard rebuilt is much less than $2500. they only get that expensive if you start replacing camshafts and such.

 

I'm thinking if you put throttle @ WOT and pump primer while trying to start it may just be a trapped air bubble , it may just be enough .. its what i have to do to the CAT 3208's all the time ...