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ISB Cummins Fuel Injection Pump

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Hi all,

Anyone know anything about repeat failures of injection pumps? 2004 Sportscoach Crosscountry ISB hpcr 300 hp.

Had pump replaced for no start 20 months ago at 29000 miles. Started acting up yesterday, check engine lite on and off. Seemed to miss at idle. Got off highway to campground ,checked in and on way to site it died.Changed fuel filter and bleed air good flow from lift pump.Will fire but not start. Iam suspecting high pressure pump bad again. Now at 42000 miles.

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ISB Engine is one of the good ones regarding the 2004 year of production.

Have you had the ECM scanned of fault codes ? That might be stored as the Check Engine light did come on.

Unless something outside the norm happened the engine should run for many more miles then you mentioned.

This year engine has a High Pressure Rail injector system and was a good improvement over the Bosh VP-44 system. Low fuel pressure from the lift pump can damage the pumps, they need good fuel flow to cool the electronics inside the pumps.

Some chassis manufactures installed a third fuel filter in the fuel line ahead of the lift pump and tucked in along the chassis frame rail drivers side close to the rear axle. This one is real hard to see and find.


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Turned out engine dropped a valve seat took out piston, injector tip,turbo,etc.

broken injector tip caused fuel pressure to drop.

After checking on coach one am went to have breakfast and was rear ended at down,c ar smashed but driveable I am Getting out of New Mexico asap. Had to order long block for coach so will have to fly back to get it.

Little bit fed up with cummins engine right now but will get over it. Dave

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Copy of a PM I received from Dave.

Sent 11 February 2013 - 10:55 AM

Thanks for your interest,

Only codes at time were egr and low voltage to ecm.voltage caused by bad
battery,egr code common when thia happens according to dealer service

They say that this dropping valves is not real uncommon.Got mh back
last week and now in Idaho,no problems so far.Had all new hoses
coolant,all filters,radiator,exhaust manifold,etc installed with
motor.manifold had small crack in it.

After thinking about this earlier,when traveling in Arkansas in
November mh started to miss coming threw mountians.We stopped to check
and it sounded like a bad valve at exhaust,i drained fuel water
seperator and it came out of miss so traveled on and it ran fine.This i
think was valve seat being loose holding valve open.Dealer says seat
coming loose is from too much idling and hot shut down.I bought mh used
so i do not know if this was ever done.Told me usally valve problem
occurs when motor still under warranty.Mine had been in storage for 4
years before i bought it.

Again thanks for your concern.Happy traveling,

Thank You Dave for letting me know that you are up and running again. Got your second PM that mentioned your well on your way home.

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