2f carb issue

[redleg76]

I have a ‘79 2f with fresh rebuilt carb from Mark A. Truck starts like a dream and as I depress choke, the thing idles at around 1400. I haven’t got the idle down to 650ish yet. Vacuum gage hovers at 17 inches. Drops when you mash the accelerator and then tops at mid 20’s when you let off, settling back at 17. I don’t have a tech, used the one at my buddies shop yesterday - I’m going to get a tach on it and start adjusting the carb. My buddy is a solid mechanic and he has adjusted on the carb to no avail.
Any help or ideas are greatly appreciated.
I’ve been putting this thing together for over 3 years and it’s all back together, just won’t tune.

Thanks!!

 

[Solace in Solitude]

Check the idle speed screw... it may be set too high.

Mark rebuilt one of my carbs and did an excellent job... my 2F runs like an SBC now.

But, I couldn’t get the idle below 1100, until I thought of the idle speed screw.

I adjusted it down and all’s good.

 

[Dizzy]

There's an adjustment on the linkage that causes a throttle hang-up if it is the wrong length. It looks like a turn-buckle after the ball on the end of the pedal. At least this was my problem on my '75.

 

[redleg76]

I will look at the linkage and confirm it is correct. The idle speed screw does not help the issue. We have adjusted the carb per recommendations in the FAQ’s and no luck. The solenoid is not working per mechanic. I’m not sure how it would work, as it isn’t plugged in to anything?

 

[77mustard40]

I will look at the linkage and confirm it is correct. The idle speed screw does not help the issue. We have adjusted the carb per recommendations in the FAQ’s and no luck. The solenoid is not working per mechanic. I’m not sure how it would work, as it isn’t plugged in to anything?

You need to get keyed power to the solenoid and confirm it does 'click' when it gets power (when the key is on). Without it you will not have a chance at a normal idle, the closed solenoid is blocking the idle circuit in the carb.

When I converted from an aftermarket carb back to a stock carb I found my wire for the solenoid on the DS fender (but I'm 77)

 

[redleg76]

My 2F is a ‘79, but the rig and wiring harness is a ‘65. Maybe I need to get power to the solenoid.

 

[Solace in Solitude]

My 2F is a ‘79, but the rig and wiring harness is a ‘65. Maybe I need to get power to the solenoid.

Definitely!! Keyed power.

 

[FJ40Jim]

The idle speed is too high, but adjusting out the idle speed screw does nothing?
Are you sure it's the idle speed screw that is being adjusted, not the choke speed screw?

 

[redleg76]

Adjusting out the idle speed screw did not help.
I ran a wire to the solenoid and it didn’t help either. I’m wondering if the solenoid is bad? I ran another ground just in case the ground was bad, but that didn’t help. I did t hear a “click” or anything when I ran power to the solenoid.
Powered the solenoid and ran the truck but it didn’t help at all. Also tried to back out the idle speed screw and no help.

Next thing to chase?

Thanks!!

 

[Dizzy]

If you really back out the idle speed screw the engine will die if the secondary is closed like it should be at idle. Usually gasoline can't get to the engine without air being pulled down the throttle bores.

Like FJ40Jim was talking about above; the one under the insulator plate, right?

 

[redleg76]

Attached pic of adjustment screw.
The trucks starts right up when choked, as I push choke on rpm’s climb (1500ish) and then when choke is fully depressed truck runs for a few seconds and sputters out and dies. Idle when choked is ok, it’s just that incant get an idle when not choked. Also, it is running really rich. Thanks for the help!

 

[65swb45]

Mark, if you don’t hear the solenoid click, it isn’t working. You will not be able to properly adjust your idle until you replace the solenoid.

And if you are fooling around with this on a freshly rebuilt engine, you run a serious risk of washing the rings out.

Cruiser Corps and SOR both sell solenoids very reasonably. Don’t fire the engine again until you’ve changed the solenoid and can confirm the click.

 

[redleg76]

@65swb45 - Thanks Mark. SOR shows a 1/75 - 8/76 replacement that has one wire/ one spade. That is the same as my carb. When you rebuilt mine is that the year range you used? Mine was a ‘79 and the primary/secondary bowl was assbackwards. Just making sure I get the correct part.

Thanks so much

 

[65swb45]

@65swb45 - Thanks Mark. SOR shows a 1/75 - 8/76 replacement that has one wire/ one spade. That is the same as my carb. When you rebuilt mine is that the year range you used? Mine was a ‘79 and the primary/secondary bowl was assbackwards. Just making sure I get the correct part.

Thanks so much

Mark

I really have no recollection of rebuilding your carb, but for the record, all 79-80 carbs are ass backwards.

If you are not running emissions, then I think a single wire solenoid will be just fine.

 

[sggoat]

Something that may further help with t'shooting----