Skip to main content ↑ ↓
Topic: Engine losing power (Read 1044 times) previous topic - next topic

Re: Engine losing power

Reply #25 –
Normal Map failure is not temp or time related. They just stop changing voltage signal.  Could be tho . any broken vacuum hose or collasped hose .  High temp reading might pull timing.  What does the ECU look at and control?

Re: Engine losing power

Reply #26 –
Quote from: Jim Frerichs –
Engine air filter was checked by Cummins 2 months ago -when they looked for my problem. Not dirty enough to be restrictive.

Thanks for the suggestion,
Jim 2002 U320
So are you indicating any restriction? If you show zero restriction verify that the filter minder is working. First remove hose from filter canister and apply low suction on the hose to verify meter movement and setting retention. Reset to zero and then verify that the air can be drawn from the filter end cap threw the 90 degree fitting going into the filter cap. It has a splintered brass screen and will have some restriction but should not be completely blocked.
Scott

Re: Engine losing power

Reply #27 –
Quote from: Protech Racing –
Normal Map failure is not temp or time related. They just stop changing voltage signal.  Could be tho . any broken vacuum hose or collasped hose .  High temp reading might pull timing.  What does the ECU look at and control?
Agreed, just saying map must work. The cam sensor does have redundant sensors but will affect operation. I don't recall any vacuum lines other than the large intake hoses that IMO are always pressurized to some degree. I have seen large leaks cause low boost, poor economy and surprisingly little power effect
Scott

Re: Engine losing power

Reply #28 –
My 2002 U320 M-11 450 goes into limp mode after 50+ miles, Insite shows no active or inactive codes thrown, no check engine light ever, turbo pressure slowly goes down to <2 psi =at fulo pedal. Normal coolant and oil temps always.  Engine idles well and accelerates easily in neutral during this limp mode. Believe no loss of CAC pressure. No squeal or noises from turbo and no white or black smoke ever.  Logically the Allison 6 speed transmission hunts with lack of turbo presure.  Oil temp and coolant temps are quite normal through all of this as read on my Road Relay 4.
During these limp modes it still idles well and in neutral it accelerates easily to 2000 rpm with normal pedal response. Believe no loss of CAC pressure. No squeal or noises from turbo and no white or black smoke ever.
After sitting for about an hour, it comes out of this limp mode when something changes and it is back on the road for another 50+ miles when something fails again or maybe tells the ECM to derate again. Guessing heat related, out of range sensor or fuel starvation.

What tests should I do? Any ideas?? Hoping Brett Wolfe and others will respond,

Jim
308-440-5154
Another idea to eliminate the throttle pedal  sensor, does it do this with the cruise control engaged?
Scott

Re: Engine losing power

Reply #29 –
Jim, I suggest you try what Scott just mentioned - eliminate the electronic foot control. When out of state (2005 ISM 500HP), we experienced the same problems with engine rpm dropping to idle intermittently at first, then later it occurred in heavy traffic --- and stayed only in idle.  The cruise control would still function at all rpms.

The fix was to replace the electronic foot pedal assembly, Foretravel part number P37336 (August 2019).  Pretty expensive fix as I found out that if we didn't need asap repair that a generic pedal speed control part might be locatable ($350 vs <$50).
Gary and Debra Rosenquest
2005 U320, ISM02 500hp, 40 ft
Texas Hill Country
 

Re: Engine losing power

Reply #30 –
Dear Foretravel friends and enthusiasts,
Happy New Year!
This is just a "Problem Resolved" follow up on a post from a couple months ago. I thank our fellow Foretravelers who all took the time to help me diagnose this "Engine losing power" issue I was having. For newbies like me, it takes a village!

After several ours of tinkering (and armed with Foretravel veteran information from this site), I finally just brought it to a local diesel engine mechanic who found (very quickly) a "kink and clog" in a fuel supply supply line.

Kit $39.30 + Labor $100 = Running good as new!

Many thanks to you all!
Mike

2003 U320 3820 Designer Series