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Raybo · 02-20-2014, 11:26 AM

370 ISL cummins shut down going about 65 MPH with amber check engine game on. Oil & water is full. It won't restart. truck repair shop said the lift pump is bad and they replaced it. still will not start any idea.

Skip426 · 02-20-2014, 11:39 AM

Unfortunately ; and I don't know if this happens as often on the ISL as it did on the Dodge Cummins ISB's; the lack of fuel to the injector pump caused by the lift pump failure takes out the main injector pump.

Is the shop able to test injector pump output pressures?
Or are they scanning for a low injector pump pressure code?

Raybo · 02-20-2014, 07:33 PM

first the shop said I need lift pump and suppresser. They replaced these and it still won't start. Know they say I need high pressure pump for about 5000.00 installed. Said it would take 10 hrs to install

Skip426 · 02-20-2014, 09:46 PM

The lift pump is the , easiest item in the Cummins fuel system to test & replace, other than the filter, if the lift pump tests bad then it has to be replaced before a test can be run on the injector pump.
BUT, the shop should have warned you in advance that the possibility of both pumps being required was there.
That is the down side, along with the cost of course.
The up side , if you want to call it that is that, by not starting the problem is being dealt with now, because all to often after the lift pump fails, and is replaced, the injector pump gives up a few hundred miles down the road.

Smitty77 · 02-20-2014, 10:40 PM

Is this a CAPS era, or post CAPS? Somewhere towards the end of 2003, CAPS should have finished their build run at Cummins. This is engine build year, not coach. (We have a 2004 model, with a July 2003 Cummins built ISL - CAPS. Sometimes called non VGT equipped.)

Sorry to hear of your problems!
Smitty

Raybo · 02-24-2014, 11:56 AM

Did a computer scan and checked pressure, but don't know what the pressure should be.

Skip426 · 02-26-2014, 03:50 PM

Did the shop get the coach running ?
Not sure what the fuel pressure from the injector pump on an ISL should be, but on an 03 and newer Common Rail ISB, it would run 30,000 PSI. If memory serves, kind of forget a bunch of stuff after 8 years retired.
I'll look around on line to see if this # is correct.

What year is your coach? I don't see a year in your profile.

Raybo · 03-03-2014, 07:27 PM

they replaced the lift pump and the suppressor. When it still did not start they said I need a high pressure pump. When this was replaced it started up and ran good. Just under 7000. Pump had to come from Memphis, Tenn.

Smitty77 · 03-03-2014, 09:39 PM

Hi Raybo - Glad the problem is fixed, sorry for the cost!

What year is your coach? The ISL370 had changes in mid 2003 (Cummins build years, but quite often still installed in 2004 year coaches.) Does your ISL have the VGT (Variable Geometry Turbocharger), this would indicate it was one of the later built ISL370's.

The fuel delivery system is different between the earlier non VGT ISL's (CAPPS), then what is in the later built ISL's with VGT.

Thanks, and smooth sailing for you ahead,
Smitty

Raybo · 03-06-2014, 06:49 PM

2004 newmar built oct. 03. Has a caps pump

Ray,IN · 03-06-2014, 08:53 PM

That is exactly why we have an extended service contract on our 2000 MH. Sorry you experienced such a failure.

Smitty77 · 03-07-2014, 09:26 AM

Quote:

Originally Posted by Raybo

2004 newmar built oct. 03. Has a caps pump

Thanks sir... Ours was assembled in July 2003, CAPS, and is also in a 04 Model that was built in Sept of 2003.

Follow question. Are you a fuel additive user for increase lubrication post ULSD, or not?

Best, and smooth sailing sir,
Smitty

Raybo · 01-25-2017, 04:55 PM

I had this problem a 2nd time. This time I removed the inlet fuel line to the lift pump an blew air toward the fuel tank. My line filter or sock in the fuel tank was stoped up not letting fuel get to the lift pump. This solved my problem. The repair shop said I needed new pumps again, but this got it running again. I purchased killem a pffp product that cleans fuel tanks.

jleamo1 · 01-30-2017, 11:17 AM

Raybo, you have two fuel filters correct? The lift pump should be between the primary and secondary filter. Sounds like you need to replace the primary fuel filter if blowing air backwards through the lift pump solved your problem. Not sure about your coach but most do not have a screen in the tank.