I am an insulation contractor in my second year of business... It is essential for me to have a box truck to keep my machinery and materials dried in and move around from job to job efficiently. Another contractor in my area contacted me, he had an older truck in his fleet he said he would give to me if I could get it running (it had been sitting for 8 years or so). I am not mechanically inclined at all, but the foreman of my crew is... We swapped the battery and starter, put some new fuel and B-12 in the fuel tank, and got it running... We moved it across town to my Dad's shop to work on it. There it sits... barely running. I haven't got the slightest clue where to start or what to look for... As an older truck, my foreman - who does his own mechanical work at home, is a little clueless too... The weather is changing for the worse here and we really need to get this truck road worthy to keep up w/ our work load. I'd really appreciate it if someone could give us some guidance - Thanks!

 

Joe, welcome to FTE.


You for got 1 important thing.........what motor does the truck have?


Do you know why the truck was parked?
You did drain any old fuel out of the tank and checked the tank for rust & crap sitting on the bottom right?
New fuel filter.
How about a carb rebuild as it had old gas sitting in it and could have gummed it up.
What shape are the plugs, wires, cap & rotor in?
When changing the plugs do a compression test so you know the ruff shape the motor is in.
Check all vacuum hoses for cracks or just broke off causing a leak.


Not hearing it run it is hard to tell what it could be.
Dave ----

 

"Barely runs" is not much of a description of the problem. I hate to say it, but if you can't work on it, and your other guy is lost, I think you are sunk.

 

https://www.ford-trucks.com/forums/forum232/


Best answered here.

 

Since it runs at all that suggests you have some kind of ignition so first thing l'd check for is bad gas and clogged fuel filter(s).

If it has a mechanical fuel pump on the motor you can run a new fuel line from the fuel pump inlet into a gas can with fresh gas and see if that helps, but you'll need to replace the carb inlet fuel filter in order to run a good test.

No way would I consider even trying to run it with 8 year old gas. After sitting 8 years it's not even gas any more. All the fizz is long gone now and it's just toxic waste.

 

Thanks for all the feedback - (it has a 6.1L 370 in it @fuzzface2) We’ve pushed through some of the routine stuff wires, plugs, hoses, filters... its running a little better. Ultimately, it will need some time with a mechanic - just trying to do what we can to offset expenses. We're changing out the fuel pump today, it doesn’t appear to be mounted to the motor. A quick google search has directed me to this part - Airtex 60144 Mechanical Fuel Pump... Could use a second opinion before I rush out and buy something. Thanks!
Also - I'm looking for something along the lines of a 1984 f600 chilton - anyone know of any good online resources?

 

You had better jump on this on ebay.

https://www.ebay.com/itm/1984-Ford-B....c100705.m4780

 

This bit has me confused. Does the truck currently have a remote electric fuel pump? The Airtex pump you mentioned is engine-mounted and mechanically driven. Something doesn't jibe...

I've no particular experience with the 370, but I have revived a few other engines that have sat for years. There will be some obvious issues such as bad fuel, but it sounds you've already taken care of that. I've had some carbs that needed a full rebuild due to fuel turned to varnish, and dried/cracked seals. Other carbs have been just fine with fresh fuel. Definitely replace the fuel filter and do a pressure/volume test at the carb inlet to ensure adequate fuel delivery.

The most common issue with a dormant engine is low compression. After long periods of disuse, the rings tend to stick in the piston grooves. The valve stems tend to stick in the guides, too. If you're getting any sputtering or backfiring, you might have a valve or two that won't fully seat.

For stuck rings, I've had good luck with Marvel Mystery Oil. Pull the spark plugs and shoot a spoonful into each cylinder with a squirt bottle or syringe. With the plugs still out, manually rotate the crankshaft a few turns to help distribute the oil. If you can let it sit a couple of days like this, that's even better. You don't have to add more oil, but do spin the crankshaft a few more times. Before you try to start it again, engage the starter but with the plugs still out. This will blow out any excess oil (can be messy) and prevent hydraulic lock when the plugs are reinstalled.

I haven't had to do much for stuck valves. Usually just running the engine at heavy load will free them up. If the engine isn't making any horrible sounds, it's better to actually work it hard once fully warmed up. Higher load equals higher cylinder pressure, which helps slam the valves closed and also free the piston rings. In pre-PC days, this was known as a (Insert name of ethnic group) tune-up, but you can't say that anymore.

Another thing to check is the distributor's centrifugal advance, assuming the timing is not electronically controlled. Pop off the cap and try to turn the rotor. It should turn about 30 degrees in the forward direction and then spring-load back to the original position. If it doesn't move freely, the shaft is gummed up. You can usually add a couple of drops of light oil into a recess on the end of the shaft and see if that helps. If the shaft is free but doesn't spring back, the centrifugal advance springs are broken.

You can also test the centrifugal advance with a timing light. Disconnect and plug the vacuum advance line to the distributor. Rev the engine and you should see the timing advance and then return when slowed. If good, reconnect the vacuum advance. Now you should be seeing vacuum advance in addition to just centrifugal advance, for a greater total advance.