Why wont my truck stay running?

First, a complete newb here. I found a '49 Studebaker 2R5 truck that had been sleeping in a South Dakota field for the last 42 years. Now, I don't know much about automotive but I figured the Stude would be simple enough to learn on and I can't break it cause its already broken




When I got the truck the motor was frozen so I poured some Marvel oil in all the cylinders and let it soak for a couple weeks. I used my tractor and gently pulled the truck in 1st gear and reverse.. it didn't take much and the motor turned over.

The carburetor was plugged with mud from wasps from top to bottom. The main jet was plugged with very fine rust powder as was most every other part. I suspect this is why the truck was parked. The fuel pump was also plugged with a very fine rust powder.

I completely disassembled the BXOV-26 carb and soaked everything for a couple days. While the carb was soaking I pulled the manifold to inspect and make sure the intake and exhaust ports were clean.. that all looked good so, I put the manifold back on.

Next I drained all the fluids and pulled the oil pan. Cleaned everything up put on new gaskets and put it back together. With motor free i removed the spark plugs and ran a compression test - each cylinder gave the same reading 110lbs. This engine is not original to the truck so I am optimistic about the compression test that this engine may be newer.

When I reassembled the carb I used a kit that only had an idle jet, needle and seat, accelerator piston, idle needle screw and gaskets. Every part that was not new (main jet, bypass jet, main discharge jet, was completely cleaned by squirting carb cleaner through the parts and they all seemed to be good. I was able to get cleaner to spray through all the carb passages and found nothing blocked.

So, here is where I am at. Put the carb on the manifold, hooked up a temporary electric fuel pump and cranked it over. It actually runs... and runs pretty good, doesn't smoke. I get 50lbs on the oil pressure gauge. Trouble is it won't stay running by itself. It will run for maybe 30secs to 1 minute after priming the carb then it stalls. When I restart it will only stay running when i fully choke the carb with my hand.

Would you please watch this video and tell me where you think my trouble is?

http://www.youtube.com/watch?v=M6dSkZJpIsg

 

tag air leak

 

My thoughts


Carb out of adjustment?
Vacuum leak?
You are not getting enough fuel if you are choking it to keepit running

I may be wrong but that is whete I would look

Good luck



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vac. leak at carb base or manifold

 

correct rebuild kit? jet/float set correct? too high of a fuel pressure? clean fuel? see pic for part you need

 

I'd suspect a HUGE vacuum leak somewhere. Carburetor base gasket on backwards?

 

Try spraying some WD40 around the base of the carb. If it sucks it in are changes the way it runs then you have a leak there.... good luck....

 

From what or where is the fuel being sourced? Are you sure you temporary electric fuel pump is providing a steady, and adequate, supply?

Ray

 

Off hand I would say it has a huge vacuum leak somewhere. Carb base or intake gasket or perhaps a broken vacuum line somewhere.

 

i didn't see where you say what your running for a gas tank.

 

Did you try to adjust the idle mixture?

 

I just went through this same issue almost. Choke carb with hand engine starts but then dies out. I swapped the intake manifold from my old engine to the new engime. So i swapped the manifold back over with a new gasket and am driving my truck again.

 

At 22 seconds in look under the carb and you'll see a big flash as you start cranking from what I'm sure is a vacuum leak at the carb base.

 

All good suggestions there.a

First I'd look for a vacuum leak.

Second if you are using the gas tank do you have a vented cap? The gas cap has to vent on that truck and if you have a new cap try loosening it and see if the truck will stay running.

Third fuel not getting to the carb due to plugged filter, kinked or bent line or other obstruction in the line. Old vehicles that sit for a long time sometimes accumulate strange crap in the gas tanks from small hands.

Is the idle mixture screw adjusted close to correctly? Screw it in gently and then back it out a turn and a half to start.


With having to keep it choked to stay running I'd think that you have a fuel delivery problem. You might want to run a hose from the electric pump to a small auxiliary tank/container and see if it will run that way and then figure out the tank/fuel line problem if it does run ok.

 

I had the same issue with an old C20 with a 400SBC. It sat for a long time before I got it. I didn't inspect the tank and someone put an inline fuel filter in at some point. Everytime I ran the thing it would only run for a short time. The filter would clog with rust from the tank and the thing died. It took me about an hour to figure it out. Since the fuel getting to the engine didn't look bad but the restriction in the fuel filter wouldn't allow the fuel to flow enough for the engine to run. Just a though on top of what else was said. You may need to flush/replace the tank.

 

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ I forgot what i was thinking.......

 

Just a 5 gallon plastic fuel can

 

That flash is from the exhaust.... there is no exhaust attached to the manifold.

 

There goes my idea.

 

I'm starting to suspect the manifold gasket? There is nothing else attached to the carb except the vacuum advance to the distributor.

 

Sounds silly but is there enough space around hose that it isnt air locking?

 

The carb kit came with two base gaskets.. I used only one. Just to rule it out, I put both on but it didn't improve anything. Should there be two base gaskets?

 

you did a great job on your video, now is the time for some pics of your carb and intake, get some light on it and take pics from all angles.