Truck Needing Carb Problem Fixed

My F-600 Single Axle Dump truck has a newer 390 Ford engine in it and it's a real workhorse truck. The problem is you have to have the choke pulled all the way on put some gas in the carb throat to start the truck, then keep the choke on most the way for it to keep running, when it's really been warmed up you can push the choke in just a little but not much. Is this a carb problem or fuel pump problem or a wife problem? I think the wife is ok so, must be something else.:beatsme

Wife!!!!!!!LOL

I think you have a couple of things going on , one would be that the accelerator pump is not working . With the engine OFF , you should be able to see two strong jets of fuel being squirted down the throats when you work the throttle whilst looking down the throats . The other thing would be a blockage of the main jet . What type of carb is it , Holley , Carter , Thermoquad etc ? If it's a Holley , the accelerator pump diaphragm could be faulty causing the first problem and the power valve could have a perforation caused by a back fire causing the second problem .

You have verified the fuel delivery pump is getting fuel to carb, and the fuel filter is clean?

Besides checking for all of the above.

How old is this carb, how many miles on it.

I had a problem like this years ago on a Chevy C-60. What it ended up being, was that the throttle shaft bushings were worn out enough to let air leak through them. So it was running lean with all that extra air coming in and the choke had to be used to keep it running.

carb

Safety Mgmt. said:

My F-600 Single Axle Dump truck has a newer 390 Ford engine in it and it's a real workhorse truck. The problem is you have to have the choke pulled all the way on put some gas in the carb throat to start the truck, then keep the choke on most the way for it to keep running, when it's really been warmed up you can push the choke in just a little but not much. Is this a carb problem or fuel pump problem or a wife problem? I think the wife is ok so, must be something else.:beatsme

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This wont help you with your problem, except that maybe it will save you money.
About 8 months ago, I bought a F800 with a 429/4b Holley. It had been setting up a few years, but the engine was a new rebuilt. All the engine would do , is backfire, but it would run a little with the choke on. I removed the carb and took it to a very good carb rebuild shop (my first mistake) I had it totally rebuilt at a cost of $490:Banghead I should have asked HOW MUCH in advance, my mistake. After I paid for it, I just happen to check with my auto parts store and they could have got me a new one for $340 HUMMMM:Banghead
Before I would mess with rebuilding this, or replacing parts try getting a price on one that you know is good. Jegs also has good prices, just make sure you get the correct replacement. It does sound like it needs rebuilding/replacing
Good Luck and keep us posted

This is a very common problem with the 390 2V or 4V engine. Besides the choke being pulled all the way out, it generally helps to pump the thottle like mad to get the accelerator pump squirting some fuel into the intakes.

Usually, these engine are very grumpy when cold, believe it or not, even in California. They love a lot of fuel warming up, and it takes forever to warm them up to operating temp.

I've found a lot of reasons for this; all the way from mis-adjusted floats and accelerator pump linkage, to mis-adjusted chokes, to wore out fuel pumps to plugged filters, to crimped fuel lines. Loose jets will also not help the situation nor will stuck needle valves. In Michigan, you will get into the running cold problem, where you might want to put in a hotter coolant regulator.

Some folks put an electric fuel pump on. Some do that and remove the mechanical pump. Ummm, another problem -- on older units -- is the accelerator pump gasket/seal/diaphragm drying up and allowing a suction leak. Then there is the possibility of some of the internal holes in the thottle body being partially or fully plugged. Oh, make sure the dern thing is bolted down tight, and maybe before doing that, slip a new mounting gasket between the carb and the intake manifold. These are quite often bad too.

You can have the carb flow checked at a good fuel shop, or buy a new one. Check/adjust the timing carefully. Check and replace spark plug wires and plugs, also points, distributor cap, and condensor. Make sure the vacuum advance works properly.

Last but not least, you can get rid of the old girl and get your hands on something newer without all the problems of the gas hog 390 boat anchor.

Good Luck!

I recomend to off that gas headeach and get yourself a diesel model! You can find all kinds of single axle tractors that a 10-12 foot bed will fit in perfectly! And you already have the bed and wetline on the gasser!

No No Ill bet its a 2300 Holley or it doesnt matter goto Napa and
get a kit about $29 . As said acc pump, but you say that you need choke out
a little all the time? Power valves are a common failure. So with new gaskets
a new power valve a good soking in lacquer thinner blow out main metering block
so so easy to do youre self. Now on the bench, this is important, I fill the bowls
up with gas and hold throttle wide open (noting a good squrt) NOW cut down
youre air gun down to about 15lbs holding throttle open squrt the air down its
throat = now you should see a nice atomized pattern of gas. Holleys are so
easy a caveman can do it. If you see the above you are good to go. Also note
they DO NOT like damp around 37 to 40* like sleet snow rain especially if they
are goverened. They freeze up and will only idle running rich as hell. When mine
do this (always) I nurse it till it stalls then walk away a little bit, restart all set.
They just need a little heat, thats why gas planes have carb heat.

I have a 91 F-800 with a 429. The original carb has been removed by the previous owner. I put a 750 Edelbrock on it, and fattened up the cruise mode with some smaller metering rods and stiffer springs on the Mrods, and it runs pretty good. Cold natured for sure, but when it warms up, seems to do pretty good. I only have one issue yet to figure out and that is when I come off of WOT, the engine starts to lay down or fail and loose speed. I can go back to WOT and it is strong again. Doesn't act up at all on the way up through the gears, just when you stand on it and then back off. It is weird and I can't figure it out.

I would definatley verify that your fuel pump is good, and that your filters are clean. Then, I would check for vacuum leaks and check your throttle shaft bushings. You can take some carb cleaner, and spray around the base of the carb and see if the engine changes pitch. If it does, you are sucking air in places you shouldn't be. After that, I would rebuild the carb, or take it somewhere and have them do it. Always do the cheap things first.

Thanks Duromax04, I'll try some of those things in the Spring as the truck has been put away for the winter. Vac surge could be your problem also when you let off from a hard surge on the accelerator. Might want to check for a vac leak or a hose hooked up to the wrong fitting by the carb. A good source to ask about your problem is Edelbrock Company. No one knows carbs like them.

Can't agree with your thoughts Rino on going to diesel chassis. This truck is a real workhorse. I can go down through a slippery slimy woods and come right back up with the two speed axle and perfect weight ratios. My neighbor bought a refitted fire truck with no two speed axle, they put a five yd. dump box on it and he cannot even fill it up with dirt a haul it down a flat surface. My five yd ford can have the dirt a foot above the truck and running off every end a just go anywhere through mud, blood, beer or sand and just keep hogging forward. I'd recommend one of these F-600 short box, high sided Ford Dumps to anyone out there. Diesel does not make a workhorse, gearing and weight ratios in a dump truck is the key.

Safety Mgmt. said:

Can't agree with your thoughts Rino on going to diesel chassis. This truck is a real workhorse. I can go down through a slippery slimy woods and come right back up with the two speed axle and perfect weight ratios. My neighbor bought a refitted fire truck with no two speed axle, they put a five yd. dump box on it and he cannot even fill it up with dirt a haul it down a flat surface. My five yd ford can have the dirt a foot above the truck and running off every end a just go anywhere through mud, blood, beer or sand and just keep hogging forward. I'd recommend one of these F-600 short box, high sided Ford Dumps to anyone out there. Diesel does not make a workhorse, gearing and weight ratios in a dump truck is the key.

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i agree with gearing and weight ratio's, but put a diesel in the same setup with same HP and you have a better workhorse because of durability and economy. simplicity helps also.

I was looking at a diesel when I bought my gasser. The reason I didn't go with the diesel is that I don't really know how to work on them, and when they break, they are expensive to fix. I can wrench on a gasser, even if it is a Ferd. A diesel is super durable, and tons of torque, but if a pump quits, that is huge money and if you loose a turbo, you are looking at big money as well.
I have to agree about gearing being key. I hauled about 6 ton of wet dirt in mine a few weeks ago, and it pulled some steep hills on high side 5th, and I never had to downshift. In fact, it pulled about as good loaded as it did empty. I was amazed. The old Love Potion #429 exceeded my expectations. However, my expectations were very low.
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