340 Starting issue

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1972trucks

1972trucks

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I have a 73 Duster with a 340. The motor has been completely rebuilt with everything being new. All engine components are new. New gas tank, fuel pump, rebuilt carb. Was having some gas supply issue with the mechanical fuel pump so I put an electric fuel pump inline and it took care of the issue. I took it out for a test drive and discovered a power steering leak. I tightened up the lines and had the car running until it quit. Now it will only run for a second or two then quits. I put a brand new carb on it and still it will only run for a few seconds. I can't figure this one out especially since it was running.
 
Maybe you lost your running voltage with the key in run position. Remember you have a start voltage and then a run voltage to keep it running. If using ballast resistor turn key to run and see if you have voltage at ballast resistor.
 
yes brand new distributor and coil. It was running good but just quit. now will start and run for a few seconds
 
Make sure you check the pick up gap! I've seen a few new distributors with way big gaps. .008 I believe with a brass feeler gage.
 
Do you know how to actually troubleshoot? Checking voltages, etc? Do you have a service manual? Multimeter
 
Seems odd that you had a fuel issue, fitted a new pump, & might still have fuel delivery issue.

After it quits, activate the throttle while looking at the carb primary throttle barrels. You should see a fuel stream from the acc pump nozzle into each barrel. No fuel suggests carb is not getting fuel.
 
OK you said it will run a few seconds. Is that like it will run in crank position and not in the run position?
 
No I haven't figured it out yet. Put in an electrical fuel pump. Tried two ways , one with it going into the mechanical fuel pump then direct into the carb. Both would run for a few seconds then die. Thought it might be getting too much few much fuel, so I put a regulator in both ways and still getting the same thing. Put a new ballast resister in and same thing. I am about ready to raise the white flag and throw in the towel. I can't figure it out. It was running. I was able to drive it down the street and back then it just quit, and I haven't been able to get it running
 
Evidently it sounds like you're just throwing parts in and not addressing the real problem. You never responded about fuel in the carb after it dies to pump the throttle to see if it is a fuel issue with fuel in the carb squirting fuel. You can jump the ballast resistor and run 12 volts from the battery to + side of the coil to see if it keeps running, just don't run it too long or you'll burn up the coil. It's either fuel or spark. If you're not capable of checking that let us know and we'll then tell you to take it to a mechanic. All the posts here have pretty much covered what it could be. But not physically looking at it we really can't tell exactly what you're problem is.
 
I am sorry. I am getting power to the resistor. After I checked it I replaced it. took off the rebuilt carb and put a new one on. I seem to be getting fuel. the car will start but only runs for a few seconds. I now have put an electric inline fuel regulator but same thing.
 
If you want help you are going to have to answer questions and be responsive. This is a two way street. NOBODY is paying any of us for our time here. I'm 74, so my time is more valuable now than ever.

1...Do you have a multimeter, some alligator clip jumper leads, a 12V test lamp and the factory shop manual? You can download that free, from MyMopar. That one and several others got there because of the guys right here

2...DO YOU have spark and how EXACTLY did you check that? This is IMPORTANT because of the way the Mopar key switch operates.

3...You say you have 'power' but we don' know how or under what conditions you checked power

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FUEL Do you have an understanding of how to tell if it is starving or flooding? Are you getting anything out of the accelerator pump? have you checked the plugs to see if they are wet/ other?

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COMPRESSION What shape is the engine in? Have you checked compression? Any recent changes, like a came change, etc?
 
Did you try post #11?

Sock in the fuel tank might be blocked with rust/debris. Since you have an electric pump, try pumping fuel from a container of fuel & see if it keeps running. Be very careful not to generate any sparks near the fuel.
 
Bewy said:
Did you try post #11?

Sock in the fuel tank might be blocked with rust/debris. Since you have an electric pump, try pumping fuel from a container of fuel & see if it keeps running. Be very careful not to generate any sparks near the fuel.
Click to expand...
My Duster did that when I first got the engine in.... damn sender looked like some cavern inside.....with all kinda junk in there
 
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