Author Topic: wrapping up 70 cuda project engine won't stay running.  (Read 1186 times)

Offline rickb

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wrapping up 70 cuda project engine won't stay running.
« on: August 11, 2013 - 04:18:49 PM »
I bought a 70 barracuda a couple years ago and did a frame up restoration. Marked everything before the teardown as well as I could. Just before the teardown the engine ran terrible, not sure why. Assumed it was the carb.
Now that its all back together with a new carb its acting the same as it was.
I have to floor it just to get it to start and it will only stay running for 20 sec or so and dies the second I let off with a loud flaming backfire out the carb. Now I'm thinking something with the ignition or coil or resistor might be incorrect, but not sure how to check because its not the same as the wiring diagram in the repair manual.
After searching for similar problems i found a bunch of threads with most of the answers way over my head.
With the ignition on there is 11v on bith terminals on one end of the resistor and 2v on both of the other end.
Any help would be great.
Thanks
Rick




Offline anlauto

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Re: wrapping up 70 cuda project engine won't stay running.
« Reply #1 on: August 11, 2013 - 05:25:10 PM »
Did you open the choke when it was running ?
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Offline MEK-Dangerfield

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Re: wrapping up 70 cuda project engine won't stay running.
« Reply #2 on: August 11, 2013 - 05:29:27 PM »
If you can get it to start, then I would lean towards a fuel problem. Is the fuel pump and fuel filter new? Does it have fresh gas in the tank? Since it has never run well, can I assume the new carb was never set up?

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Offline rickb

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Re: wrapping up 70 cuda project engine won't stay running.
« Reply #3 on: August 11, 2013 - 05:52:33 PM »
It was dynoed on a stand after built with the carb, just dif ignition system.

Offline anlauto

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Re: wrapping up 70 cuda project engine won't stay running.
« Reply #4 on: August 11, 2013 - 06:29:41 PM »
In your picture it looks as if the electric choke is not wired in and the choke plate is definitely in the closed position.
It will stay closed if not hooked up. :2cents:
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Offline Rich G

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Re: wrapping up 70 cuda project engine won't stay running.
« Reply #5 on: August 11, 2013 - 06:56:52 PM »
My friends charger ran the same way and it was a weak coil. For a quick check for spark I'd pull the coil wire from the dist. and hold it about an inch from the manifold (or any ground) have someone crank the engine over. You should get a nice big arc and spark crack. If its very weak that could be your problem. Check the gap in the dist. too. Its hard to ck the coil or control box. I just swap them out with known good one. Buddys cars when there not looking. Backfire is usually ign or a very lean cond. But if your saying it ran good on the dyno with a different ign. that would be the first place I'd look.

Offline rickb

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Re: wrapping up 70 cuda project engine won't stay running.
« Reply #6 on: August 11, 2013 - 07:44:20 PM »
Yes, held the choke open with a screwdriver for now.
Not sure where to wire that lead to yet too.

Offline anlauto

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Re: wrapping up 70 cuda project engine won't stay running.
« Reply #7 on: August 11, 2013 - 08:01:00 PM »
The choke stat is adjustable....loosen the three screws on it and turn it until it holds the choke open....

I'm leaning towards more than one problem though....could be ignition too
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Offline Chryco Psycho

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Re: wrapping up 70 cuda project engine won't stay running.
« Reply #8 on: August 11, 2013 - 10:00:13 PM »
Connect the choke wire into the Blue 12v feed circuit , it goes to the ballast & the alternator .
 if it ran fine with a different ign system that is the problem , what system did you dyno with & what are you using now ? Did you use the same dist or coil ?

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