5.9 Cummins Engine Sputter when warm

[Flitzeflap]

Hello All! I am the proud new owner of a 1997 BlueBird with a 5.9 Cummins Engine. I am from Germany so this is a very exotic bus and little info and no parts available. So great that I found this forum!
I have one problem at the moment with the enigin. When its properly warmed up after lets say 30 minutes on the highway it suddently starts to sputter and it feels like the engine is starving from diesel. Speed goes down from 60 to 30 mph, more stutter, black smoke and then it comes up again. Does this on a regular basis.

I am familier with gasonline engines but not with diesel. WOuld it be a gasoline I`d say there is dirt somewhere in the fuel line.

So what would be the start to look for the problem?
Thank you very much in advance!

 

[2kool4skool]

Welcome! Filters....Change the fuel filters first.

 

[Flitzeflap]

O.k. Will do! Is there a downloadable parts book for the cummins? I have the owners manual of the Blue Bird but nothing about the engine. So I can make sure to order the right ones!

 

[2kool4skool]

Our Cummins is a 2000 year and we use F519579e for the filter on the engine and FIL 3621 for the under body one. HTH

 

[Flitzeflap]

great thank you! So I just try to find a Dodge Manual for Cummins Engines and follow the service prodeducers?
Or is there a specific repair/service manual für cummins engines in the blue birds?

 

[Flitzeflap]

I just found this on ebay:



https://www.ebay.com/itm/1997-OEM-C...639944?hash=item342193e508:g:gJcAAOSwGBpeQHPs


Would this be usable for the cummins in the blue bird?

 

[2kool4skool]

Has the bus run well before this ?

If the bus has a VIN, I would contact Blue Bird and ask for manuals or any info.
There's a difference between the Dodge pickup truck engine and the bus engine. For example the oil filter looks the same but the threaded portion on the engine is larger.

There's experienced bus repair/maintenance folks on this forum, I hope they can contribute.

 

[BamaBus]

I just found this on ebay:



https://www.ebay.com/itm/1997-OEM-C...639944?hash=item342193e508:g:gJcAAOSwGBpeQHPs


Would this be usable for the cummins in the blue bird?

It may be usable if you have the ISB engine and not the 6BT. Go to https://quickserve.cummins.com/info/index.html and create a free online account to enter your engine serial number. It may give you some useful info.

 

[magnakansas]

lift pump, fuel pressure

1997 cummins 5.9 should have a bosch P-7100 fuel injection pump. Two things I can think of will hurt performance. IF the fuel shut off solenoid is not functioning correctly The engine may die or act like it is very low on power....As Go to you tube an search, there are videos about the pump and shut off solenoid.... your bus or other kind of truck, the idea works the same in all them with a P-7100 pump

fuel feed to pump..... there is something called a "lift pump" the fuel is sucked from the fuel tank by the lift pump, then is pumped to the fuel injection pump. pressure from the lift pump should be around 25 psi to 35 psi or 1.5 bar to 2.5 bar..... there are many causes for low performance, most are related to not enough fuel getting into the engine. some are related to lack of turbo pressure... when the turbocharger fails, you will usually have lots of black smoke and no power.

when fuel fails, you have clean exhaust and no power.

hope this gives you some insight. telephone if you wish to speak.... I assume you are in the United States and are not in Germany.

785 207 7600

william

 

[Flitzeflap]

Hi William,



in fact I am in Germany. Right in the Bavarian Alps near Munich. Therefore I always get lots of attention when I drive the bus because you do not see them here.



I have indeed lots of black smoke coming out once it looses performance on the road. As said it only happens when I am on the highway at full speed.



How can I check the turbocharger for proper function?


Where are you located? So I can check the time difference when call.



Fabian

 

[magnakansas]

loss of power, black smoke

well this is a start. do not worry about time difference call any time, does not matter to me if I am asleep or otherwise.

find, purchase and install "turbo boost pressure" gauge another name would be "Intake manifold pressure" or "manifold pressure" gauge. I believe this help find the problem.

sound to me like you have a a hose or piping that is leaking air pressure. Possibly the waste gate, or air restriction... stupid stuff like a plastic bag in the air cleaner..... you know mechanics have the habit of putting covers on open holes so you dont drop things in to the open holes.. but also means sometimes the covers are left in place... like a rag left in the wrong spot and now you a cloth somewhere it should not be....

Look at video "how to check your turbocharger" does not matter if it is a diesel bus or heavy truck or race car.... the turbo charger is the same, some are bigger than others,,,, If the you have a lot of wear and the turbo stops spinning you will have the effect you are talking about,

The black smoke means you have large amounts of fuel and not enough air to burn that fuel.... so you are getting too much for some reason or not enough air. I cannot think of anything that would cause too much fuel... The fuel system usually fails with too little fuel, not too much fuel.

That leads me to think you are losing air some how....

the turbocharger is working correctly and there is an air leak. rubber hoses are not clamped correctly, piping is broken/ split or not installed correctly. "intercooler" or "charge air cooler" or "aftercooler" all the same part with different names is broken/damaged. or there is an obstruction of some sort.... Come to think of it.. IF the exhaust is plugged up, blocked, that is also an obstruction that will prevent the turbo from exhaling. no path to get the exhaust out will also kill turbo operation.

Turbo charger is not working correctly

go watch some videos on these subjects, gain some knowledge if you need the information. I do not know your level of knowledge about this subject. once you know enough you may find the answer on your own.

call any time night or day

william 785 area code 207 7600 telephone number

 

[Flitzeflap]

Hi William,



thank you for the great explanation so far! I will order the parts and the start checking for leaks. Generally I think if its running I cannot be that bad. But I know from the gasoline engines I have worked on so far that a little vaccuum leak or the like can give you big headache! And to find the problem is sometimes harder than a major issues of course.



At the moment we are facing shutdown of businesses due to Corona. Since I have my own business I will probably only start working on the bus again after the virus craziness is over. But I will keep you posted!


Stay safe and healthy!


Fabian

 

[Doktari]

Welcome. Let us know if replacing the fuel filters helps the problem.
I would check the temperature carefully to see how hot it is running before and after the problem occurs. Diesels need to run hot but not too hot to run optimally. Maybe someone ran biodiesel in your bus before you got it. In which case the filters very well could be plugged. Also someone mentioned checking for a plugged exhaust or a rag in the wrong place.