67 Chevy rough idle, shakes, stalls????

B.B. Hemingway

B.B. Hemingway

Well-known member
Don't know if we have any good mechanics on the board :D , but I'll hold out hope. I'm a self-taught one myself, and could use a little help.

I have a 67 chevy truck. I just changed out the fuel pump (diaphragm) a few days ago. Ran it for 15 minutes after I put the new one on and it ran fine. The next day I had a few minutes of free time so I went and and started her up again. Ran it for 10 minutes or so. All seemed good. Today, I was finally going to get her out, and it was rough to start. Once started she idled really rough, began to shake, and stalled out once I took my foot off the gas. Started it a couple more times.... same thing.

Anybody have any ideas?

(Spark plugs/wires have been changed recently)

 
I'm self-taught as well... I've only delt with fouled plugs that caused missfires in my old car. You could have damaged the plugs when you changed them and it's just now showing up, but I would think that would just give you miss fires and a really rough idle, not stalls. Maybe a bad diaphragm in your case, or dirty filters/carb. I would guess it's something in the carb or fuel system. Recheck your installation and make sure you didn't miss something. Then make sure nothing is plugged up.

 
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I have no reason to be in this thread but you didn’t put ethanol fuel in it did you?  What you described is exactly how my diesel truck acted when I accidentally put unleaded in it. 

 
ZRod said:
I'm self-taught as well... I've only delt with fouled plugs that caused missfires in my old car. You could have damaged the plugs when you changed them and it's just now showing up, but I would think that would just give you miss fires and a really rough idle, not stalls. Maybe a bad diaphragm in your case, or dirty filters/carb. I would guess it's something in the carb or fuel system. Recheck your installation and make sure you didn't miss something. Then make sure nothing is plugged up.
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I had the carb rebuilt about a year or so ago. Not sure what would of went wrong when installing the fuel pump (if the diaphragm is bad it'll spray gas out the vent hole, right?). If the push rod wasn't up at install it wouldn't of pumped fuel to allow it to run for 25 minutes. Appreciate the insight!

commando said:
my guess would be a plugged filter...but tough to tell from my computer chair.  lol.
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like the fuel filter?

krc1995 said:
I have no reason to be in this thread but you didn’t put ethanol fuel in it did you?  What you described is exactly how my diesel truck acted when I accidentally put unleaded in it. 
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I would never put that ethanol s#!t in my baby  :D

 
Take the breather off and check the fuel stream into the carb. Check the timing. Make sure the air filter is clear. Make sure the choke is opening. Listen for a vacuum leak.

 
Sounds like its starving for fuel or a vacuum leak to me,and I'm going to need to see a picture of your truck,67-72 Chevy trucks are my favorite.

 
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