1998 ISM INFO

[walt2137]

I have a neighbor who bought Bill Fauber old coach a 99 exe with a ISM coach built in 98 and he is having problems with the fuel getting to the injection pump my question is what type fuel pump (pump from fuel tank to injector sys)does the ISM have, the ISC before 2002 or 3 had a fuel pump that came on for a couple minutes at start up then the injector pump took over. Im pretty sure the 98 ISM was HP injection system?

 

thanks Walt

 

 

[Ivan K]

ISM does not have a lift pump, it only has a gear driven pump on passenger side of the motor with a single line going to the injectors. From factory, there probably was/is a Wynn purge pump that, if working, would push the fuel up to the gear pump with manual intervention, not with every start attempt. This however is normally only needed after filter change. Is that what happened?

[walt2137]

Thank Ivan   The coach has been setting for a few months and the owner said he was getting ready for a trip and the coach started then cut off right away and would not start after many attempts . I think it may have that slime problem from the fuel tank but i didnt know about the fuel pump configuration and wanted to try and get info on the set up. Im not sure about the Wynn as i have not been to the coach.

any thing else you can think of.

Bill F passed a couple yrs ago and his wife wanted to sell the coach as it had been setting for about 5 yrs in a covered parking , Sharon ask for help in selling the coach and i knew my neighbor was looking because he tried to buy my coach, i gave him Sharon info he made a deal with her and bought a full set of batteries and 6 new tires and went to San Antonio TX and drove it back to Mississippi .

Bill F was a member of Al P old MCOA and later with Bill D when he started Monacoers 

 

[Ivan K]

Walter, the fuel and filters could always be a suspect. There is also a shutdown valve so it can be bad too. It can not be mechanically externally operated unfortunately but you could check its outlet. There was a post recently that seemed related. It also has a pic of the fuel flow.

ISM 500 No Start https://www.monacoers.org/topic/6070-ism-500-no-start/

[vanwill52]

Walt, good to hear from you!

I agree with Ivan.  The symptom you described is certainly indicative of a clogged filter, especially since the coach has been sitting for some time.  Several of us on this forum have installed a FASS fuel pump to preclude filter problems and insure the injection pump is never starved for fuel.  After installation, be prepared to change the FASS primary fuel filter several times in a short period.  The FASS pump has a large flow, uses a dedicated fuel return line and is constantly filtering the fuel in the tank.  Over a period of time it will "polish" the fuel in the entire tank.  If you install a remote-reading fuel pressure gage AFTER THE SECONDARY FILTER, you can use it as an indicator of when a filter needs changing.  I changed filters several times in rapid succession after installing the FASS pump.  With fresh filters, the system pressure is 15 PSI.  As filters clog, that pressure drops.  I change at least the FASS primary filter when pressure drops to 10 PSI at WOT.  I don't change filters based on time-in-service any longer.  I will always pre-fill filters, just due to habit, but the FASS system is self-priming.  After installing the FASS pump, and especially for a coach that has been sitting a long time, it would be a good idea to disconnect the fuel line at the injection pump inlet and let the FASS pump "purge" the lines of any accumulated slime.

The FASS system has two filters of its own, and I now use a third 2-micron final filter.  That is overkill to be sure, but the FASS system easily maintains pressure through it.

[walt2137]

18 hours ago, Ivan K said:

Walter, the fuel and filters could always be a suspect. There is also a shutdown valve so it can be bad too. It can not be mechanically externally operated unfortunately but you could check its outlet. There was a post recently that seemed related. It also has a pic of the fuel flow.

ISM 500 No Start https://www.monacoers.org/topic/6070-ism-500-no-start/

Thanks again Ivan for your help , i printed out the picture of fuel flow for my neighbor.

[jacwjames]

If it is algae you will see it in the filtering system.  Back in 2009 I had a bout of algae, the top of my primary filter was almost plugged. 

I would recommend treating with some sort of algaecide, I use Biobor but there are other.  I would have multiple sets of filters available as if you have algae you will go through filters. 

I also agree with FASS system, I took Van's suggestion 2 years ago and installed a system.  This was after I found the lift pump on my 8.3 ISC leaking. 

 

[walt2137]

Good to hear from you Van , im not working on his coach only passing on info to him. At 86 it getting harder to do maintenance on my coach i am mostly fooling with gardening . We haven’t traveled in our coach in apr 3 yrs and don’t expect to be doing much traveling but life is still good and have a lots to keep me busy, couple yrs ago i bought a little bandsaw mill to play with and if i get bored i can go cut up a couple logs.

12 minutes ago, jacwjames said:

If it is algae you will see it in the filtering system.  Back in 2009 I had a bout of algae, the top of my primary filter was almost plugged. 

I would recommend treating with some sort of algaecide, I use Biobor but there are other.  I would have multiple sets of filters available as if you have algae you will go through filters. 

I also agree with FASS system, I took Van's suggestion 2 years ago and installed a system.  This was after I found the lift pump on my 8.3 ISC leaking. 

 

James i think that is a good chance some of his problem but the Fass pump system i dont think will help him on the ISM Engine as i think the fuel system is more like the later ISC Engines with the HP inj fuel system. Thanks James!