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AMC 401 runs only on starter fluid

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BDCVG View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote BDCVG Quote  Post ReplyReply Direct Link To This Post Posted: Jul/01/2022 at 11:02pm
Distributor in wrong .
1970 AMX 390 5 spd full Control Freaks front and rear suspension
2014 E63 AMG-S wagon
1965 Austin-Healey 3000 MK III              
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Post Options Post Options   Thanks (0) Thanks(0)   Quote zeebo76 Quote  Post ReplyReply Direct Link To This Post Posted: Jul/04/2022 at 12:11am
Got her running properly yesterday but didn’t have the time to post until today.

Turns out it was, indeed, the carburetor.  After a rebuild and a slight tune she cranks up immediately.  I also did away with the (nonfunctional) electric choke and went manual because I’m lazy and don’t feel like troubleshooting another thing.  I’ll deal with it someday, I still have all the parts.

Also did a coolant drain and refill, with a little flushing action courtesy of a water hose.

She’s a proper dual exhaust truck, the right cylinder bank smokes a bit even though every cylinder had good compression.

Edit:  oh, also the P.O. had the plug wires ordered wrong.  That definitely didn’t help things.


Edited by zeebo76 - Jul/04/2022 at 12:13am
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Post Options Post Options   Thanks (0) Thanks(0)   Quote rsrguy3 Quote  Post ReplyReply Direct Link To This Post Posted: Jul/04/2022 at 8:47am
Awesome, that is a sweet truck! 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Photon440 Quote  Post ReplyReply Direct Link To This Post Posted: Jul/05/2022 at 10:55pm
Perhaps with those years of inactivity, the valve seals have cracked, causing the smoke.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Mr_Roboto Quote  Post ReplyReply Direct Link To This Post Posted: Jul/06/2022 at 6:26am
1-Have you disconnected the outlet line of the carb, stuck it in a jar to ensure that it is giving you fuel? Could be your fuel pump diaphragm has a hole in it. If it sat with ethanol fuel increases these odds.

2-If you look into the bores of the carb and then completely open the carb's butterflies do you see it squirting any fuel?

If the first test passes, you may have stuck needle valves. Have you checked to ensure they are moving freely?

Also did you pull the fuel inlet fitting off the carb its self and see if the filter there is plugged.


ED:
missed the last post. Guess I am posting too early. Good on getting it running.


Edited by Mr_Roboto - Jul/06/2022 at 6:28am
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Post Options Post Options   Thanks (0) Thanks(0)   Quote zeebo76 Quote  Post ReplyReply Direct Link To This Post Posted: Jul/08/2022 at 2:14pm
Final update on this thread, for everyone's satisfaction.

Turns out I didn't rebuild the carb as perfectly as I had thought - I started having choke problems, as in - it wouldn't run without the choke "on", even when warmed up.

So I caved and bought a new carb (edelbrock performer), and everything's perfect now.

Over the past several days I've driven it quite a bit, and it's flawless apart from running a little hot!  I can elaborate if anyone's interested in helping diagnose, but otherwise I'll leave it here.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Mr_Roboto Quote  Post ReplyReply Direct Link To This Post Posted: Jul/08/2022 at 2:26pm
What do your plugs look like? Probably a good idea to make sure it's not lean. Also, is it hot at standstill or when moving down the road?

Lastly, did you hook your vacuum lines up in the same way to the new carb. Make sure you have vac advance hooked up so you have good timing when crusing!
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Post Options Post Options   Thanks (0) Thanks(0)   Quote zeebo76 Quote  Post ReplyReply Direct Link To This Post Posted: Jul/08/2022 at 2:32pm
Originally posted by Mr_Roboto Mr_Roboto wrote:

What do your plugs look like? Probably a good idea to make sure it's not lean. Also, is it hot at standstill or when moving down the road?

Lastly, did you hook your vacuum lines up in the same way to the new carb. Make sure you have vac advance hooked up so you have good timing when crusing!

It's primarily hot at standstill, but will also warm up over time while moving, it just takes longer.  It doesn't do a good job of eliminating existing heat, if that makes sense, driving at speed just prolongs the inevitable.  Once it reaches 'hot", that's where it generally likes to stay.

I'll do some fiddling with the mixture screws later today, probably, and check a plug at that time.  Lean plugs would have a white-ish hue to their tips, correct?

I did actually hook everything back up the way it came off - vacuum was on ported, not manifold.  Thanks for the speedy and helpful response!

Edit:  Oh, also, everything on the motor's been softened up and there's no smoke whatsoever anymore.  Big smile


Edited by zeebo76 - Jul/08/2022 at 2:36pm
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Heavy 488 Quote  Post ReplyReply Direct Link To This Post Posted: Jul/08/2022 at 2:59pm
Idle mixture screws aren't going to affect how hot. A crap cooling system that's been sitting for years will.
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