Cummings 400 ISL engine won't accelerate -

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JKH

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2004 Monaco Dynasty 400 Cummings ISL engine idles fine but won't run when acceleration -- just dies back to idle -- can barely touch accelerator and get some acceleration sometimes only to die again. MotorHome has old fuel and has been recycled through filter and put back in and changed both Fuel Filter and Water Seperator and Algie chemical put in fuel tank.
 

Utclmjmpr

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You obviously know you have a fuel problem,, do you know you may have TWO filters to change?.>>>Dan ( It also is a CUMMINS) engine)
 

jubileee

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Sounds like no signal from throttle pedal to ecm. Suggest checking, cleaning, wiggling all connections from throttle to ecm. The pedal is just a throttle position sensor and could be failing.
 

JKH

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Bamberg SC and Hilton Head Island, SC
Utclmjmpr said:
You obviously know you have a fuel problem,, do you know you may have TWO filters to change?.>>>Dan ( It also is a CUMMINS) engine)

Thanks -- changed both - water seperator and primary filter.  Did prime the filters and then read in manuel NOT to.  Don't know if this really matters or not, never not primed a filter on other stuff.
 

Gary RV_Wizard

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Priming filters runs the risk of introducing dirt beyond the filter, potentially damaging the injectors.  Filters can be primed via a safe procedure, but most people just pour some fuel in the big center hole.


If all filters are fresh and the fuel in the tank is clean, I would remove the fuel lift pump and check its inlet screen. If the fuel was dirty or had algae, the crap collects on the lift pump inlet screen and blocks the flow.
 

Utclmjmpr

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Most water seps. are on the bottom of the PRIMARY filter,, you no doubt have a SECONDARY filter also mounted usually on the engine and about one half the size of the primary, easily missed.>>>Dan ( The electronic controls were in use in 2003,, but not the accelerator sensors.. Cables were still being used then)
 

jubileee

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Utclmjmpr said:
Most water seps. are on the bottom of the PRIMARY filter,, you no doubt have a SECONDARY filter also mounted usually on the engine and about one half the size of the primary, easily missed.>>>Dan ( The electronic controls were in use in 2003,, but not the accelerator sensors.. Cables were still being used then)
All my truck engines (Cat 3406E and up) and friend?s truck engines ( Cummins ISX) had throttle by wire from about ?98 or so on that I?m aware of. Motorhome and ISL maybe different, but there has to be a TPS somewhere.. I guarantee the ECM doesn?t have a lever hanging out of it.
 

Gary RV_Wizard

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Cummins allowed single filter systems in 2003, so there may not be a secondary. I had a 2003 Freightliner chassis with the ISL and only a single separator/filter.
 

Chakara

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Rio Rancho, NM
Reusing old unknown fuel seems risky - even with filtering and separating.  I'd be tempted to put in new clean fuel and see....

 

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