Troubles, Can you help?

[KJ's Dodge]

Pulled the truck out this morning with the intent of heading to a car show but...I am stumped. Again, I have a B1 RA with a 282 cu. in. Molly block with factory dual carburetors.

The truck runs and starts fine. One crank and she lights up, runs great until it is warmed up. I have tried every thing I can think of:

New points - check

Gapped properly - check

New fuel pump (changed it out twice now) - check

New condensor (changed it out twice now) - check

Rebuilt carbs - check

New flex line supplying the fuel, frame to block - check

New battery fully charged - check

Fluid levels fine

I do have a slight water pump leak but I do not see how that could be the issue (waiting on Bellows seal and than I will rebuild the water pump). I know I have a charging issue and still need to get that addressed. I will try some fresh gas later today and see if that is the issue (I am going to kick myself if it is). Once it warms up to about 150 degrees F, it just sputters and will not run!

Your guy's thoughts? Any help/insight you can offer would be appreciated!

Thank you,

KJ

[Todd B]

Sounds like a coil problem.

[KJ's Dodge]

Nice try but I should have added that to the original list.

New coil - Check

Maybe it is a bad new coil?

Thanks for the input,

KJ

[B1B Keven]

Have you checked for spark after she dies?

[Todd B]

Vapor lock?? Take off the gas cap and see if it dies.

[JBNeal]

check yer spark when cold, run engine until it starts to run afoul, then check spark again. If the spark starts white, then runs to a yellow, then yer coil is might be given ya the fits.

[raidmagic]

If you have a charging issue you could be having a spark problem from the electrical system being down on voltage.

[bach4660]

do you have a heat shield ?

[mechresto]

Have you tested your heat riser? sounds like it's stuck in the closed position, which will anwer up the exact result youre experiencing. thru warmup runs fine, when heat riser should open it doesnt causing fuel to boil in carbs and sputter, once it cools for a bit it runs well till temp rise. and well lather rinse repeat!

[KJ's Dodge]

First off, thanks for the insight. I will try and chase down some of this later today. Purchased another new coil just in case.

The heat shield around the fuel pump is in place.

It is not a vapor lock at the fuel tank.

I am not familiar with a heat riser, so I will have to find that.

With a fully charged battery that is new, these 6 volts do not draw that much that a lack of charging while it is running in the short run IMHO should not be a problem (ie, I am not running the lights or other electric items).

KJ

[Dodgeb4ya]

Don't bother with the heat riser issue-the Moly motors don't have heat risers.

[JBNeal]

Something to consider is your electrical grounds on your truck. These trucks were riveted & bolted together, so there is a possibility that a cumulative resistance is building up once the truck heats up.

one problem I ran into with the '49 was the original battery cables, which appeared to be in decent shape, were actually corroded between the copper strands throughout their lengths. This had a cumulative resistance that cropped up once the engine heated up, and hot re-starts were purt'near impossible. Replacement with new cables with soldered terminals practically cured the hot start problem.

While trying to figure out this hot start problem, I removed the starter & took it to my starter/generator guy in town. He found no problems when he tested the starter, but he did volunteer that routing the chassis ground cable to one of the starter mounting bolts would provide for quicker starts compared to having the original ground located at the transmission housing. This coming from a guy who rarely spoke up about anything, so I took that piece of advice as words to live by.

Another thing to consider for chassis grounds is the chassis construction. The frame is mostly riveted together; these rivets and the hole surfaces in the frame the rivets pass through corrode, increasing resistance. The transmission ground location is also a concern, as the path to ground from the starter alone has to cross threaded bolt surfaces that can corrode, further increasing resistance.

It is summertime in my neck of the woods for practically 1/2 the year, so by late summer, the battery has to be recharged to overcome the resistance drags that still exist in my frame. A fix that works on paper is to locate short welds at frame member attachments to fuse the frame together rather than being clamped together with rivets. Also using a ground strap to the engine, cab, etc. from the frame should also improve grounding continuity.

[Dave72dt]

You may have a fuel (lack of) issue. Partial blockage anywhere in the lines or fittings may give it enough fuel for idling and warmup but not enough for ful bore running. Give particular attention to the fitting at the fuel tank.