I recently picked up a 1986 R5D, it had some stalling / starting issues at purchase, the truck had been sitting for two years.

First thing I noticed was fuel bowl float was not set properly and the bowl was filling to much, I removed the top end adjusted the float until the bowl was ½ way full. When I reassembled the truck the owner I had purchased it from had forgot to connect one of the EBCV hoses to the Carb, and connected the vacuum line that should have went to the MC Valve instead. When I put everything back I connected the EBCV hoses to the carb and vacuum line to the MC Valve as in the repair manual. (Edit: It is the original California feedback Carb, it looks as if it was rebuilt before I became the owner.)

When I started it back up it ran much better, the surging idle was gone and the truck seemed to quit stalling. However after ~3 miles the truck cut off while coasting down a hill around the 3rd gear range. Tried to restart and couldn’t get it to catch, seemed as though it was almost flooded. Peaked down the carb no fuel was overflowing, looked in fuel bowl it was still around the ½ filled mark as it should be.

I was able to start it once with the hood raised and air cleaner cover off, however when I closed the hood the truck stalled. So, then I tried again this time removed the air cleaner and all EBCV lines tried to start it again still wouldn’t start. Any insights on most likely culprits? And where to begin trouble shooting?

 

Find a copy of the factory service manual that goes over the carb and how each part works. Its the only tool that will help you rebuild and repair the stock carb. The service manual needs to be for your year truck as changes were made each year to the carb.

 

Just my best guess but sitting for 2 years, it's likely the idle passages have some sort of obstruction in them. Those passages are tiny & it doesn't take much to completely or partially plug them up. This is more common than you might think. Could also be a little bit of crud partially or completely blocking the idle jet at the base of the fuel bowl. On carb'ed pickups that have been sitting, I routinely remove the fuel bowl drain bolts & shoot carb cleaner down the vent tubes to "wash out" the fuel bowl, & get access to the idle jet to shoot some cleaner through it. I follow this up with a little compressed air. Really stubborn blockages I also remove the Idle Mixture Screw & the Fuel Cut-Off Solenoid to put some cleaner into the interior idle passages, plus some compressed air. Usually works.

 

Thanks guys! Tore down the carb, cleaned it out, re assembled, put it back on Still had issues 🤷‍♂️ So I Broke down bought a Weber 32/36 yanked the smog equipment, cleaned the fuel tank. Will tune it Monday, and hope Weber’s are worth the hype.

 

Webers are good but you have to set them up correctly. Will need a Holley fuel pressure regulator and gauge. Set fuel pressure to 2.5 psi. Buy a proper carb adapter. Throw out that two piece adapter it comes with. Test the manifold with a smoke machine to make sure you have no vacuum leaks, if you have a leak you will be chasing your tale trying to tune it. Connect the vacuum advanced as follows. All so test the advance mechanism in the distributor to see if the diaphragms are still good. If they leak LCE sells a new advance mechanism.
Borrowed this from kawazx636
Technically, you could run without either vacuum advances hooked up, but your power and fuel economy will suffer.

If you are only going to run one advance off of the distributor, you want to run the advance port closest to the radiator back to the carb (and cap the other port on the distributor). On a weber, it hooks up to the only vacuum port on the carb. On a factory carb (desmogged setup), run it to any vacuum port and cap the rest on the carb.

If you are going to run both advances off the distributor, follow the above steps on the port closest to the radiator and run port closest to the motor to a manifold vacuum advance and cap off all the unused manifold vacuum ports. This is how I have mine setup and I run perfectly fine.

Here's a picture that I found online:

"Ported Vacuum/Normal advance" goes to the carb vacuum advance.
"Manifold Vacuum/Idle advance" goes to the manifold vacuum advance port.
Everything else is capped

 

@superex87 thanks! I did pick up the stock to Weber spiral Adapter from LCE Performance along with the EGR block plate, and manifold plugs to plug all the extra Cali Vacuum lines mine had. I got a Holley FPR from summit racing as well.

I also dropped the gas tank, cleaned it out and placed a filter in-line with the pump as my in tank sock had disintegrated.

I’m hoping this solves the issues with idle / stall, once it’s running smooth I have a leaky timing cover that I’ll deal with down the road.

I would have never thought to use smoke/fog to look for vacuum leaks great idea. I always was shown to spray carb cleaner around seals.