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whe8913
Advanced Member
United States
301 Posts |
 Posted - 09/22/2010 : 7:16:52 PM
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Want to see if someone can help with this problem....1994 Ford bus with a 5.9 Cummins. The bus starts and immediately dies. I can hold the fuel solenoid arm up and it starts and runs fine. Let it go, and it drops down and dies.
I have replaced the fuel cutoff solenoid, but it's still doing it. Where do I need to look next?
Thanks! |
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BJ Henderson
Advanced Member
USA
280 Posts |
Posted - 09/23/2010 : 05:01:10 AM
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Those solenoids have a start circuit in them and a run circuit. That is the reason they had three and four wires going to them, four wires in the later models. Sounds like you have some kind of open circuit in the run side of the solenoid. I'm assuming you adjusted the linkage when you installed the new solenoid. Of course it's a Ford, and with that many years on it, the open could be anywhere. On those circuits the wires are 12gauge and I usually looked for the usual problems first that would be obvious, wires at connector ends with blackened stiff insulation, or any point with high resistance in that circuit. Do a voltage drop test across those circuits.
From what you are describing, I am assuming this engine has the Bosch piston plunger type pump, not the rotary pump.
Hope this helps. |
CMTT,CMAT,CMBT |
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whe8913
Advanced Member
United States
301 Posts |
Posted - 09/23/2010 : 08:00:14 AM
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Thanks for the help! It has the three-wire harness going to it. You're right about it being a FORD..... but the price was right (free) for what we do with it. We've had it about 4 years. It has air brakes- thank goodness, and actually hasn't given any mechanical trouble whatsoever until this. It's got 119,XXX miles on it and I don't have any complaints for a 2 day-a-week use as a church bus. If I had to have actually bought a bus, I wouldn't have gone with the Ford.
So, you're saying some time-consuming wire tracing is in order. What about installing a push-pull cable, like mechanical IHC's used to have? I would want it to pull to kill it and push it in to run, so as not to confuse drivers with the IHC's. I don't know if this pump is set up that way. I assume it's got the piston pump. Hard to tell- I know it's actually a Cummins engine, but Ford sure liked to re-badge everything with their name on it. |
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BJ Henderson
Advanced Member
USA
280 Posts |
Posted - 09/23/2010 : 7:14:38 PM
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Since you did install a new solenoid,
First check to see if it needs adjusting before you do anything else. You should be able to find the procedure online. I remember adjusting them, but not sure I remember well enough to tell you the correct way to do it without actually being there. Someone else might be able to tell you more. With the new solenoid, if it will pull the lever down when you are starting the engine, and hold it down once the engine is running, the electrical is usually good.
Hope this helps |
CMTT,CMAT,CMBT |
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jperkins
Active Member
USA
41 Posts |
Posted - 10/02/2010 : 5:58:02 PM
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| check for blown fuse or bad relay had a T-300 Kenworth with same problem and it was a blown fuse |
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IBTMech
Top Member
USA
973 Posts |
Posted - 10/03/2010 : 1:51:03 PM
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| I haven't worked on one of these, but I would suspect there is an oil pressure switch involved somewhere. |
If it doesn't fit, FORCE it.
If it breaks, well, it needed replacing anyway.
Pullin' wrenches for 45 years. |
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whe8913
Advanced Member
United States
301 Posts |
Posted - 10/04/2010 : 07:53:05 AM
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Thanks for re-visiting my post! I was about to get it going again, as I have checked it out all I can and can't seem to find a problem with wiring. All the fuses under the dash for the chassis are good- leaning toward the solenoid on the pass. side wheel well, where the starter wire comes off of. Is there a way to check it out? What about any other solenoids that I may have overlooked along the way?
Oil pressure seems good....don't know about any oil pressure switch problems. One thing I hated about Fords is their ambiguity of the gauges. No numerical psi indicators, just the needle goes to the middle of the "low" and "hi" side of the gauge. It rises when I step on the gas pedal, so all seems fine there.
Also, I didn't find any broken/shorted wires in my "investigation." The fuel shutoff solenoid is adjusted as properly as it can be. Had a certified mechanic look at it and he says it's right, but he doesn't have the time at the moment to do any more with it. Gotta get it to stay running, so help any way ya can, THANKS! |
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tigger2
Advanced Member
USA
470 Posts |
Posted - 10/05/2010 : 11:32:59 AM
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| Disconnect the lever end of the solenoid, turn key on, bump starter, and watch the end of the solenoid to make sure it stays in/or out as the case may be. If the solenoid stays put it is good and so should be the wiring. Hold the lever on the fuel pump in the on position and see if the solenoid connection is at the same point as the lever. If not adjust the end linkage till it is and reconnect. The solenoid must go to full travel to engage the hold in coil. pull coil is about 20 amps. and hold coil is about 2-5 amps. |
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ford/cummins engine start problem
