Asthmatic semi

[Chancer]

I've got this old Ford Cargo semi (I think that's what you call it) to cart my horses around in, and the old girl's got this funny problem.

Sometimes, when I'm tooling along with my foot relatively hard on the gas, I reach about 45mph and all of a sudden the power just drops off, for about 10-20 seconds, then appears to come back - as if the engine had winded itself or something. At first I thought it had to do with an exhaust which was needing changed, but it's still doing it after having fixed it. I listened out of the window when it happened last night, and I am sure that the engine actually died, but the truly wierd thing is that I still have power steering, which I guess I wouldn't have if the engine had really stalled.

The engine's a 110 hp 6 cylinder deisel, and the thing's 23 years old, so nearly ready for sending down the road, but I'd like to get one more year out of her... It's not even as if it happens all the time, but it scares the hell out of us when we've got one of the horses in the back!

Any ideas?

 

[jeepcherokee95]

How's the air filter?

sounds like it is not getting enough air under load but that is just a guess!

JC95

 

[Chancer]

Er, I think it's OK, although I changed it last about 2 years ago, the thing's probably only done 1000 miles since then, so maybe it's worth a look. Would that produce sporadic problems though?

 

[DrMoab]

Change the fuel filters....I bet that is the problem. Older deisel moters have to have clean fuel or they will do exactly what you are describing.

 

[cmotsvt]

You could have something like a paper towel or cigarette pack wrapper in the fuel tank, that gets caught up in the fuel pickup. Then when the truck looses power suction is decreased and the wrapper floats away from the pickup.

 

[Chancer]

Thanks very much for those suggestions - a proper service is in order, I think! :cheers:

 

[dyna]

See if at the times of power loss you have any smoke, black,white etc. Yes fuel filters are critical on diesels as well as leaking fuel lines which will let air into the system. Most of the pumps are fuel lubed so this is not good. Check any wiring to the fuel shut off solenoid if it has one. A loose connection would cause fuel starvation and no power.
who is the engine builder? Cummins? Iszusu? etc.

 

[Chancer]

It's a Ford, as far as I can tell. Does anyone know how to prime the lines? I know that when the fuel filters were changed before there was a bit of bother because they needed that. Yeah, maybe they do need changing - I think that that was nearly 5 years ago!

 

[cmotsvt]

I dont know if there is a hand pump on the side of your filter housing then use that. If no hand pump the fill the filter full of diesel then install filter, crank engine, repeat as necessary.

 

[Matthew Currie]

On some there's no hand pump, but you probably still need to open a bleeder on the top of the filter housing, and crank until fuel comes out. On my old Mercedes, you open the bleeder and then hand pump it.

 

[dyna]

Some ford built trucks used a Cummins 6 cyl turbo, much like a newer dodge pu, there also is a 4bt which is a 4cyl(killer cherokee transplant). Look at the front right side of the engine if standing in front. There would be what looks like a timing gear cover and behind the case will be the injector pump. There should be a tin tag with motor info on it. also depending on year there should be a manual or electric lift pump that feeds the injector pump. If its a manual it will be on the drivers side near the bell housing half way down the block. It will look like your basic fuel pump, if its this type there is a small lever on the side that is a thumb primer lever. try pumping it down, you should feel it doing something, if not try rotating the engine 180 degrees because the cam has the pump arm loaded and it wount pump. If this still dosent work the lift pump might be shot which is not uncommon. The thing will still run most likely but this will lead to an untimely death of your injector pump due to lack of fuel lubrication. Do you have a hard time starting when facing up hill in front? if so its a sure sign of a bad LP. Get some engine info if you can and Ill try to provide more info. Is it turbo?? If you have no power and its turbo you may have a boost leak at a boot or intercooler if equipted with one.
Let me know.

 

[Chancer]

It's just a plain old non-turbo ford unit, 110 (ahem!) eager horses under the driver's seat, along with a huge pile of rust. Oh well, at 6.2 tons unladen, I won't be getting any speeding tickets!

Forgiving my facetiousness, but I'll have a look for the pump once I get the cab lifted. Thanks for that.

 

[dyna]

Non turbo diesel??? well no wonder why its a little weak, are the problems new to you or has it always been like this?

 

[Chancer]

Well, we are talking about a 23 year old vehicle! The base Cargo engine was pretty soon superceded by the turbo units which, I agree, are a lot better. The problem's just come on in the last few months, so I think it's probably the fuel filters - they've not been changed in about 4 years, since I did it last, so it wouldn't surprise me if they weren't working as well as they should.