1961 - 1966 F-100 & Larger F-Series Trucks Discuss the Slick Sixties Ford Truck

390 won't idle!

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Old 07-09-2018, 09:03 PM
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390 won't idle!

I have a 1962 Thunderbird with a 390 ci engine. I had to replace the fuel tank after winter because it had a ton of crap in it and contaminated the fuel system. I replaced the tank, flushed all lines, cleaned a replaced filters, cleaned the carb internally (float bowls, jets, passageways all crudded up).
When it stopped running and needed to be towed home, it would not stay running. Now I have done all this work and it still won't idle. Once the choke is off the engine quits working.
So having been through the entire fuel system I am now stumped! Anyone have a suggestion on next place to look? Could it be an electrical issue like a bad coil or reg?
I have a car show this weekend and would like to show it! Please help!
 
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Old 07-10-2018, 04:17 AM
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Well you are in a truck forum and none of these 61-66 trucks came with a 390 although some have had them transplanted in. That said, assuming your fuel pump is working correctly and the float level is set correctly. It sounds like you still have crud plugging the idle air bleeds. The fastest way to fix that is to get a rebuilt carb from the parts house. Unless you have a bucket of that old timey take the hide off an elephant carburetor cleaner that you can soak it in for a couple of days.
 
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Old 07-10-2018, 10:33 PM
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Originally Posted by Bdsbird
I have a 1962 Thunderbird with a 390 ci engine. I had to replace the fuel tank after winter because it had a ton of crap in it and contaminated the fuel system. I replaced the tank, flushed all lines, cleaned a replaced filters, cleaned the carb internally (float bowls, jets, passageways all crudded up).
When it stopped running and needed to be towed home, it would not stay running. Now I have done all this work and it still won't idle. Once the choke is off the engine quits working.
So having been through the entire fuel system I am now stumped! Anyone have a suggestion on next place to look? Could it be an electrical issue like a bad coil or reg?
I have a car show this weekend and would like to show it! Please help!
Is it a Holley carb or other? Having to keep choke on to run is telling you its running too lean. Not enough fuel. As other said idle circuit is plugged.

If its a Holley remove idle air adjustment screws and blow both ways into air bleeds with a good carb cleaner. (just watch the eyes) . If no cleaner spray is coming thru you will have to remove the transfer plate and clean.
 
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Old 07-11-2018, 06:57 AM
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X2. Your carb is still dirty or out of adjustment. Need to completely disassemble, clean, and check specs. Depending on the carb, some will flood if the float is out of adjustment and actually idle better with the choke partially closed because it moves the carb to fast idle...counterintuitive and yet it can happen.

Getting a rebuilt carb might be the fastest fix.
 
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Old 07-11-2018, 11:26 PM
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Originally Posted by Boss9F100
Is it a Holley carb or other? Having to keep choke on to run is telling you its running too lean. Not enough fuel. As other said idle circuit is plugged.

If its a Holley remove idle air adjustment screws and blow both ways into air bleeds with a good carb cleaner. (just watch the eyes) . If no cleaner spray is coming thru you will have to remove the transfer plate and clean.
I thought I had cleaned it out but looks like I finally have it solved!
Thanks for your help!
 
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Old 07-11-2018, 11:28 PM
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Originally Posted by '65Ford
X2. Your carb is still dirty or out of adjustment. Need to completely disassemble, clean, and check specs. Depending on the carb, some will flood if the float is out of adjustment and actually idle better with the choke partially closed because it moves the carb to fast idle...counterintuitive and yet it can happen.

Getting a rebuilt carb might be the fastest fix.
I gave it one good final cleaning today and it's running great now! Thanks for your help!
 
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Old 07-11-2018, 11:31 PM
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Originally Posted by Boss9F100
Is it a Holley carb or other? Having to keep choke on to run is telling you its running too lean. Not enough fuel. As other said idle circuit is plugged.

If its a Holley remove idle air adjustment screws and blow both ways into air bleeds with a good carb cleaner. (just watch the eyes) . If no cleaner spray is coming thru you will have to remove the transfer plate and clean.
Gave it a good cleaning and now it runs great! Thanks for your help!
 
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Old 07-12-2018, 02:13 PM
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Originally Posted by Bdsbird
I gave it one good final cleaning today and it's running great now! Thanks for your help!
Cool ! Thanks for the follow up.
 
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