Complete Power Loss under load

[emcdevitt]

93 automatic, 3. 54 rear end, quad cab. When pulling trailer at 65 or 70 mph in OD going up grade, when I put my foot in it to maintain speed, the engine complete cuts out. No missing, it just stops. When I lift my foot off the pedal the engine comes right back on. Of course, I loose about 5 mph when this happens. This only happens under load and when I attempt to increase power. I never had this problem before and it just started about three months ago. Fuel filter and air filter had been replaced earlier this year. I use to be able to go up these grades at 70 mph with 25 psi boost and 900 deg turbo inlet temp with no problems. Engine has 65K miles and has always had maintenance done per schedule. I have gone through many tanks of fuel but still have the problem. Two different dealers have never heard of this problem and say it must be bad fuel or a dirty fuel filter. I am original owner and have been pulling the same 5th wheel for 7 years. Any one out there experience this? Any suggestions? Would appreciate any help. Thanks much.

 

[Power Wagon]

Sounds like the linkage is pushing against the power feed wire going to the solenoid, and breaking the connection when you reach a certain point in the travel.





Check all the connections, re-route the wires, see what happens.

 

[emcdevitt]

Thanks for the reply. I knew this had to be the solution because is seemed so logical. I inspected the wires to the fuel valve and the associated wire bundle very carefully. I was hoping to find a bare or worn wire or bad wear spot; however, I could find no indication of any abnormal wear either on the wires or the wire bundles. I moved the wires and bundles while the engine was idling but I could not make them short out in any way. Movement of the linkage caused a very small movement of the wire bundle but still no wear spots. Any other ideas? It seems to happen when the engine temperature is high. This last weekend it cut out and didn't fire back up for 4 or 5 seconds. I started pulling off the road because I thought it was a dead horse but then it fired back up. Thanks for your info. Ed

 

[BCaldwell]

complete power loss

emcdevitt, just a stray thought only happens when hot fusible link, solder joint in wire harness or possibly wire itself breaking contact. bill.

 

[BushWakr - RIP]

You know,,,, I really wonder if your fuel solenoid is on its way out.

There are two connectors on that thing. One is full voltage to trigger the solenoid, the other is lower voltage to maintain it open.

Thats sorta how it was explained to me. Now, if there is a fault, or the start of one, it may be releasing momentarily, then re-triggering. I'm just thinking out loud but I do not know if it can be "diagnosed" prior to replacement.

I had this discussion with Bill last night (BCaldwell)

Have your tried a call to PDR and asked Piers or Al??

Its free. .





bob.

 

[emcdevitt]

Bill, I looked again at the wire bundles and connectors associated with the fuel valve. Still can't find any problem there. Your suggestion might be why I only experience problem when temperature is on high side. I'd feel better if I could actually find it. Thanks - Ed

 

[emcdevitt]

Bob, I wondered about the fuel solenoid too. The only thing I couldn't tie together is why it would only happen under a good load. I don't know if the higher range of temperature has any thing to do with it either. When I'm pulling a grade with the fiver in tow my temp always goes up some where between the second and third point. I'm sure it's just the load of pulling up the grade thats triggering the fault causing the engine shutdown. I've been searching through the 93 shop manual for some clues but haven't had much luck. I know the Auto Shutdown relay goes to the field windings of the generator - - does it tie in anyway to the fuel solenoid - - like through the computer?

I'm new to the TDR web site and don't know what PDR is or who are Piers or Al. Could you fill me in on that. Thanks, Ed

 

[BushWakr - RIP]

I honestly don't know if it ties in or not. Now I'm gonna have to go look cause you got me curious.

As for PDR and Piers and Al, here's the link to their site.



http://www.piersdiesel.com/



Great guys, when the solution can't be figured out by most of us, they can usually help. .



bob.