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Loss of power at wot

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Arkabutla Mississippi
Thread starter #1
I have a 2002 3500 c&c and I have seen some threads describing the same problem with no results. I’m having loss of power at wide open throttle after about 2500 rpm. New fuel filter today (6/1/18). Hooked my solus scanner to it and the desired rail pressure will show up to about 200mpa. When the power loss occurs I can watch the actual drop down into the teens and the trans will not shift. I can back off the throttle a little and the rail pressure will come back up and the trans will shift. The frp actuator desired and actual stay around the same. I can hear the turbo spool and I have no smoke. It will puff a little smoke when free reved. Truck is all stock no tuning or gauges. The pump was replaced about a year ago Maby 15k miles by me. Injectors have been replaced at some time and balance rates show near perfect. I can not see any kind of fuel in the oil. All help is appreciated. Thanks.
 
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Location
Arkabutla Mississippi
Thread starter #2
Edit***** I ran the truck back from a friends house tonight and paid more attention to my solus. I found that the max frp is 159mpa and the fuel rate maxes at 89mm3. the rail pressure will make 159mpa but will drop out and if i hold the fuel pedal long enough it will start to come back up.
 

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FRANKENBURBAN
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Max rail pressure stock is 160, and max fueling is 89mm3 of fuel for a federal engine. At wot does your actual rail pressure match your desired within 5mpa?
 
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Arkabutla Mississippi
Thread starter #4
No it does not. It will drop down into the teens. I have seen it as low as 12mpa wot when the pressure drops out. If I hold it long enough it will start to come back up. And it is a fe9 code engine.
 

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FRANKENBURBAN
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No it does not. It will drop down into the teens. I have seen it as low as 12mpa wot when the pressure drops out. If I hold it long enough it will start to come back up. And it is a fe9 code engine.
If your desired rail pressure is 159-160 and your actual drops below 140, you have some issues. Since you say the injectors and cp3 are not that old, I would start by checking for fuel restrictions. The rubber lines where they bend around the transmission are known to get soft and collapse cutting the fuel to the engine off. I would hook a fuel restriction guage to the pressure port and make sure your vacuum doesn't exceed 5 inches. If it does you need to find the kinked line or blockage. If your fuel restriction tests good but rail pressure drops under hard load, then a fuel return rate test is in your future to find your high pressure leak. It will either be an injector(s), cps, or high pressure relief valve(very rarely fails, but it has happened).
 

WarWagon

Well it hits on 7 of 8...
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#6
Some other things to look for aka air leaks.

Wix plastic fuel filters leak air around the WIF sensor. ( use a metal body fuel filter.) The primer can leak air. The filter housing can crack.
 
Messages
42
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Location
Arkabutla Mississippi
Thread starter #7
If your desired rail pressure is 159-160 and your actual drops below 140, you have some issues. Since you say the injectors and cp3 are not that old, I would start by checking for fuel restrictions. The rubber lines where they bend around the transmission are known to get soft and collapse cutting the fuel to the engine off. I would hook a fuel restriction guage to the pressure port and make sure your vacuum doesn't exceed 5 inches. If it does you need to find the kinked line or blockage. If your fuel restriction tests good but rail pressure drops under hard load, then a fuel return rate test is in your future to find your high pressure leak. It will either be an injector(s), cps, or high pressure relief valve(very rarely fails, but it has happened).
I’m gonna get with my matco man and see if I can get the restriction gauge kit and Che I that then will prolly be replacing the rubber lines and rebuilding the filter head. I will see my matco man Wednesday. I’ll get back when I get the restriction tested.
 
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Location
Arkabutla Mississippi
Thread starter #8
Well matco man turned up with nothing. Snap on man wanted about $360 for the gauge so no go there. I rebuilt the filter head today (6/9) with no change so next is replacing the rubber lines at the filter head. I need to try to find a gauge set up to measure this fuel restriction.
 
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Location
Arkabutla Mississippi
Thread starter #9
Update**** got the dreaded p1093 code today. Me and my wife went to parents this weekend to visit which is a 270 mile trip one way and of course I didn’t take my scanner with me. Got home earlier and checked codes and had the 1093 code. I’m starting to believe it’s pump time.
 

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FRANKENBURBAN
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Pump, injectors, popoff, basically anything that can restrict fuel flow under load, return excess fuel, or not build pressure. I prefer to take the time and diagnose the system. Check for air leaks, fuel restriction, but don't forget fuel return. It only takes 1 or 2 injectors with excess fuel return to cause low pressure codes.
 
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Location
Arkabutla Mississippi
Thread starter #12
I will be diagnosing properly. Any parts I replace will be replace because they needed to be replaced. I’m no shadetree. I will find a length of clear half inch hose to check supply and returns with. I don’t know about the return rates but balance rates on the injectors check almost perfect. I’m on my way to work now. When I get there I will che k the balance rates again to verify. It drops rail pressure at about 2500 rpm and around 145mpa commanded rail pressure. Thanks for your help so far.
 

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FRANKENBURBAN
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I will be diagnosing properly. Any parts I replace will be replace because they needed to be replaced. I’m no shadetree. I will find a length of clear half inch hose to check supply and returns with. I don’t know about the return rates but balance rates on the injectors check almost perfect. I’m on my way to work now. When I get there I will che k the balance rates again to verify. It drops rail pressure at about 2500 rpm and around 145mpa commanded rail pressure. Thanks for your help so far.
Are you checking corrected balance rates or just displayed? It can help give some basic clues to injector health to check corrected numbers and then ramp rail pressure up and see if they hold steady.

http://www.thetruckstop.us/forum/threads/proper-way-to-check-balance-rates.41579/
 
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Location
Arkabutla Mississippi
Thread starter #15
Balance rates all checked between -1.2 to -2.0 in park and -0.5 to -1.3 in drive with the brake applied. Fe9 truck and the desired and actual frp is at 35mpa. Don’t think injectors should be ruled out completely but I believe I have more important things to look at first. Also ran cylinder contribution test while I was here. All cylinders tested within 670 counts.
 
Last edited:
Messages
42
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Location
Arkabutla Mississippi
Thread starter #18
Update**** My wife went to get a bale of hay earlier today and truck started acting up on her real bad. Got it home and I jumped in it and hooked my scanner up and drove it. It’s dropping pressure now in second gear under light throttle. Got it back und upon further inspection found the primer pump sucked down, the rubber fuel lines at the filter head sucked down, rubber lines at left side of engine pulled down. Lines under truck were not sucked down so I’m thinking the supply line at the left side of the engine is collapsed. Another thing is it has the factory dual tanks on it. I just replaced the transfer pump after a couple years of the rear tank being full and not used. I may have stopped up the fuel cooler with algae from the rear tank if there is any in it.
 

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FRANKENBURBAN
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Staff #19
The fuel cooler is on the return side of the engine, if it stopped up the engine would either not run, or most likely it would blow a return line. Sounds like restriction is your issue, now to find the culprit. Don't forget to check the hoses at the ficm for kinking.
 
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Location
Arkabutla Mississippi
Thread starter #20
I had thought the cooler was on the return side until I got up under the truck earlier and saw that it had 1/2 line ran to and from it. It’s for sure on the return side? I’ll get back under the truck when I get home from work but I believe it is plumbed with 1/2 line. Back to the restriction part. If my lines are collapsed at the engine but not under the truck then it would seem the supply line at the left side of the engine would be the culprit correct? I’m thinking very heavily about running all new rubber hose to the engine when I install a lift pump. The lift pump will be ordered right after I sell my fourwheeler which will hopefully sell in the next few days. The factory filter head will be deleted when the lift pump is installed also.
 
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