fighting with engine to idle

[richard2717]

1969 C10 with 307 2 barrel carb. new fuel pump new rubber hoses front and rear. Truck will start up but unless you keep it revving in the higher rpms it will shut off. Hit the accelerator a couple pumps and it will fire right back up but will not come close to idling. What should I be looking for at this point? I swapped the carb from my Blazer and it still does the same thing, but to be fair that carb has sat for a couple of years as well. I don't want to just go throwing parts at it if possible.

Thanks
Richard

[richard2717]

And to be a little clearer, If I close the choke it will stay running but if I even barely open the choke it shuts right off.

[geezer#99]

Vacuum leak.
Since you swapped carbs, I’d think it could be intake gasket.

[richard2717]

Originally Posted by geezer#99

Vacuum leak.
Since you swapped carbs, I’d think it could be intake gasket.

This motor was supposedly just put together by someone else for the PO so i suppose that could be a very real possibility that they did not get the gasket seated right. Are there any ways to tell for sure without pulling the intake?

[geezer#99]

Could try spraying starter fluid at the intake ports. If the rpm increases you have the culprit.
Worst case is it’s on the bottom side of the port and won’t show up easily.

Sometimes you can hear it inside a valve cover.

[richard2717]

I think I have it figured out but won't know for sure until my carb kit gets here from rock auto. The base of the carb I have on it now from the 72 motor, physically bolts up to the intake but is not the same perimeter as the 69 carb. I did not notice the hole being exposed on the right side for what I am assuming is heat riser for a choke. It gets hot enough I could not keep my finger there for long but it definitely has a bad vacuum loss. and it seems to want to run better the short time I had my finger on it. The 69 carb leaks from all the gaskets so I am ordering a rebuild kit from Rock Auto and pray I have the patience to rebuild it. I included a picture of the hole I am talking about.


.

[AussieinNC]

Am I seeing a missing carb mount bolt ?

Check that stud mount hole does not go all the way through to the intake plenum.

[richard2717]

Originally Posted by AussieinNC

Am I seeing a missing carb mount bolt ?

Check that stud mount hole does not go all the way through to the intake plenum.

the 72 model only uses 2 bolts to hold down on opposite corners. The 69 used 4. The gasket between the carb and intake is blocked off on those 2 holes.

I will be putting the 69 carb back on once I rebuild it

[geezer#99]

Originally Posted by AussieinNC

Am I seeing a missing carb mount bolt ?

Check that stud mount hole does not go all the way through to the intake plenum.

No you’re not!
Some Rochester 2 bbls only used 2 bolts.

[richard2717]

Ok I got the rebuild kit today and have it pulled apart and have a question that I hope someone can steer me correctly. I watched a couple videos and the ones I watched (not the exact carb I have) all showed a ball in the bottom of the pump intake along with the spring. There is a ball in the kit but there was no ball in the carb when I pulled it apart. The kit covers 3 different carb styles so would I be correct saying that there is no ball supposed to be in this one? The sheet says #41 ball used in types with seat casting and it looks to me like there is a groove in the bottom that it would sit in. I tried to get a clear picture of the interior base where the ball would sit.










Based on the looks of the inside when I pulled it apart, I am surprised it ran at all.

[geezer#99]

The po likely lost that check ball.
Easy to do.
I’ve ever seen one not be in there.
I’d put it in.

[richard2717]

Forgot to update this post. I got the original carb put back together and on the engine yesterday. I finally have a runner that will idle as well. Had one small leak on the fuel line coming in that just needed to be tightened a little more but got that taken care of. I have another question I am hoping to get some help with. On the passenger side of the intake there is a small rectangular box that is directly below the choke shaft. Nothing was there when I got the truck and the choke just kinda flutters back and forth at the moment. Does anyone have a picture of what I should have there and haw would I go about opening the box on the intake if that is required? Picture with arrows of what I am talking about. I am assuming where I have the green arrow can be popped up with a screwdriver, but i have been known to break a lot of stuff with assumptions


Thanks


.

[geezer#99]

That’s the cover for the divorced choke coil. It should be held down by a screw or bolt.
Here’s a link to the parts of a divorced choke. Just an example.


https://www.carburetion.com/Products...Part=9035set-C

[richard2717]

Thanks after some research I found some part numbers which led to these. At that price I think I will try to bend up a rod to work or try to adapt a manual cable and forget about it all together.

https://www.ebay.com/itm/18639663148...iABEgLO-PD_BwE

[geezer#99]

Coat hanger wire bends nice to make linkage.
That cover pops off if you pry inside that slot at the bottom.

[richard2717]

Originally Posted by geezer#99

Coat hanger wire bends nice to make linkage.
That cover pops off if you pry inside that slot at the bottom.

great Idea. I did get the cover to pop off and made sure the coil spring was still there. Now to go to the house and see if I even have any metal hangers. lol

Thanks for all the help with this
Richard