Hard Starting Cummins

[racer478r]

I have a 2000 Monaco Diplomat with a 8.3 ISC Cummins. Before this last incident when I would go to start the MH I would wait until the dash light would go out and crank. The motor would start with very minimum. cranking. The main injector pump went out and I had it replaced. Now after sitting 4 to 5 days and try to crank it takes several moments of cranking to start. Will crank immediately after this first start and the same next day. I have waited several seconds before trying to start to make sure lift pump (replaced last year) is working and it will crank normal.

Is there some sort of leak back into system that could cause this problem? There are no fuel leaks. thanks in advance.

Charlie

[obedb]

Sounds like you are losing prime to me. After setting for a few, can you reach the filter with a wrench? Take it off carefully and if the filter is not full the problem might be upstream. Perhaps Brett could weigh in on a solution. Check valve bad. My Series60 Detroit had a check valve that caused problem for some. I was lucky with mine though.

[wolfe10]

Yes either a leak on the suction side (allowing air into the fuel system) or a bad check valve (allowing fuel pressure to bleed off) can cause your symptoms.

As ObedB suggested, first check is if you have any air in the primary fuel filter. If so, you have a leak on the suction side of the fuel system.

After that, put a fuel pressure gauge on the system.

[racer478r]

Thanks for replies, will check these out.

[dickandlois]

racer478r, This link might help.

http://community.fmca.com/topic/7186-cummins-isl-and-isc-engines-with-caps-fuel-injector/

Rich.

[racer478r]

Well, problem solved: algae in tank and fuel, partial clogged filters. I had an additive for algae but guess it didn't work.

[dickandlois]

Good News, Algae in the fuel will plug up things.

Thanks for posting the solution.

Rich.

[wolfe10]

Well, problem solved: algae in tank and fuel, partial clogged filters. I had an additive for algae but guess it didn't work.

Out of curiosity, what algacide did you use?

Be aware that algacides will prevent the multiplication of more algae, but you will still have to remove the dead bodies of the existing gremlins.

[manholt]

This is my dumb question. What kind off algae, or anything else, grows in diesel? Is this related to Bio fuel?

[wolfe10]

This is my dumb question. What kind off algae, or anything else, grows in diesel? Is this related to Bio fuel?

Actually, a good question. Algae/microorganisms do not grow in clean diesel. And to my knowledge not in B5 or B20 either.

They DO grow at the water/diesel interface if there is water present. It starts as black particles in the primary fuel filter/water separator. In bad cases, long, stringy "black slime" is formed.

There are two ways to get water in diesel-- and you can reduce your chances by doing a couple of simple things:

Fill at stations with a lot of turn-over-- if 18 wheelers fuel there, likely the fuel has not sat in the station's tank for months.

Do NOT fuel if you see a fuel truck delivering fuel to the station. Those very high volume "dumps" into the tanks stir up any water or dirt in the tank.

When storing your coach:

1. Fill fuel tank to reduce condensation. Any air in the tank when you park will condense its moisture out when the dew point of the air in the tank is reached. So, if you have 50 gallons of hot humid air in the tank and the temperature drops below the dew point, you can condense a cup or more of water. That water, being heavier than diesel falls to the bottom of the tank, where the diesel above keeps it from ever evaporating.

2. If storing the fuel for more than 2 months in the summer or 3 in the winter, add a BIOCIDE. Biobor JF is a very common one. Where you live in Galveston, you can find it at any marine store, as boats have the same issues storing diesel. Biocides will kill any of the microorganisms present, but their "dead bodies" will still be caught and can clog the fuel filter(s).

[obedb]

I almost never fueled anywhere but high volume outlets. With the saddle tanks on most of the trucks I drove I could shine a strong flashlight beam into the tanks and see no gunk. Only the shiny bottom was visible.

Sure do wish that I could get a look into the tank on the used coach we recently bought. I remember something called Water Finder Paste used years ago. You lightly coated a clean piece of wood such as a wooden yard stick and touched the bottom of a tank that you were unable to look in. There was a color change if water was present. Might work for a DP. Anybody know if such a compound is still available. Guess I could goole it.

[obedb]

Answered my question. It is available at Tractor Supply among others. gasoila.com

[manholt]

Thank you Wolfe! Hope to see you in Redmond...currently in Canyonville with ACC pre-rally. Thanks also, to ObedB.

Carl C.

[wolfe10]

Thank you Wolfe! Hope to see you in Redmond...currently in Canyonville with ACC pre-rally. Thanks also, to ObedB.

Carl C.

Will be there-- here is the schedule of seminars I present:

Thursday, the 14th

Suspension Seminar Thursday, 9:45 am in Seminar 4 This seminar will be webcast.

Caterpillar Engine Maintenance 3:00pm - seminar 10, swine barn

Diesel RV Club Business Meeting (5:30 p.m. - 7:30 p.m.) dairy barn

Friday, the 15^th

Ask The Experts will be on Friday, August 15, at 8:00 a.m. in Seminar 4. This seminar also will be webcast.

[racer478r]

I have been using a cleaner/conditioner for over a yr. in every tank. This was supposed to take care of lube for injectors and eliminate the environment for microbial contaminants.

I just ordered some Bibor jf treatment. Thanks.

Also this was the first time that I have brought mh in with out a full tank, my mistake.