Need assistance w/ 1974 Dodge van engine repair

Automotive
#1

I have a 1974 Dodge van RV conversion (V8 360 engine) that I have been restoring for a year or so. Until recently it ran fine, but a couple months ago it conked out on me. My limited engine repair skills lead me to believe that it is a fuel system problem, as it cranks just fine but does not catch. Squirting a bit of fuel into the carburetor gets it to turn over for a cycle or two but then dies.

Looking for advice, or potentially someone who I bribe into assisting with repairs. Given that it would be hard to get the vehicle up to the 'space, it would have to be worked on at my house in central Irving.

Thanks in advance!

#2

My incredibly miniscule amount of any type of auto experience says check fuel filter, pump and line. I had a similar ish problem on an f150 and it was the filter clogged but not so clogged it wouldn’t run fuel. INCREDIBLY MINISCULE AMOUNT OF AUTO KNOWLEDGE but I’m curious to see what the problem is on yours since it’s quite similar to what I had.

#3

Check your rubber fuel lines. Those can crack & cause it to suck air.

#4

Does the truck have an electric pump? Have you verified the condition of the fuel lines and hoses? Do the carb bowls fill up? Will the engine start with the throttle partially opened?

#5

Put a pressure gauge at the fuel line before it reaches the fuel filter. If the pressure is low, its the pump. Try again after the filter.

Fuel pressure for carbed engines is usually pretty low. Less than 10 PSI is normal.

#6

If the truck has an electric pump. There is the possibility it runs entirely on the diaphragm pump, in which case vapor lock is a real concern, not to mention general pump failures.

My point is, we don’t know enough about the truck to effectively troubleshoot.

#7

Thanks all for the suggestions, I do appreciate them greatly. This at least gives me a few things to try out.

Will take them all into account once I am under there this weekend, and update the thread with success/failure and lessons learned.

#8

I’m NOT advocating it, but I’m saying sometimes with fueling problems, thinking outside the “tank” can help…

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#9

Bob,

1 - make sure you have fuel in the fuel tank!

If spraying a little fuel or starting fluid into the carb gets you rvan to run, then you have a fuel issue. I’d suggest removing the coil wire (to eliminate an unwanted spark in the next step), this will require a second person for better results. Remove the fuel supply line that feeds the carb (it may be a threaded metal line-if so do not over tightnen) & (there may be a filter inside, if it has a threaded fitting) or the filter may be in line between the pump and the carb) or rubber on a barbed fitting and have the other person crank the engine over several times - to see if fuel is exiting the fuel line.

If not - either the fuel pump has failed - about $35 +/- and two bolts (pretty easy) or you have an obstruction in the supply (tank, screen in tank, line from tank etc).
Your 74 Dodge has a mechanical fuel pump mounted on the passenger side of the block near the water pump (if my memory serves me correctly).
These pumps put out about 5 to 8 psi of fuel pressure.

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