Yellow truck-79 F350 460 C6 4x2 Edelbrock intake, Holley carb

This afternoon, coming home from work, I let the ponies run, which included checking for proper operation of the kickdown rod and fully opening the secondaries...

As I rolled up to a stop light, the engine stalled. After a moment, I was able to get it restarted, but had to keep the RPMs above about 1100 to keep it running.

I'd experienced this situation before, when I lost a vacuum line or cap, so I continued to two-foot (one on gas, one on brake) it on home

Once home, I pulled into the service bay (my carport) to have a looksie. Of course the truck wasn't running, but there were dark puddles on the intake manifold, and I could see the occasional clear drip from the vacuum diaphragm that opens the secondaries. The vacuum hoses all looked good.

It's dark now, so I'll look at it again tomorrow, but I think maybe I blew out the diaphragm? By the way, this is the same truck that wouldn't idle last Sunday, with an apparent vacuum leak that I never did find

 

hopefully you find it this time

 

I'd be looking for a stuck float.

 

x2 on a stuck float. Check secondary fuel level. Look for bad needle/seat. Gas is most likely leaking from secondary throttle shaft. Bad secondary diaphragm will not leak gas or cause vacuum leak.

 

Or quite possible if you don't use your secondary bowl much that you got some trash in between the needle and seat.

 

Update...

Pulled off the air cleaner and activated the electric fuel pump. I have a nice fountain coming out of the rear vent.

I'll be pulling the carb now to check out the needle, seat and float!

Thanks for the suggestions-I'll let you know what I find

 

Solved!

Pulled the carb and took off the secondary float bowl.

It's one of those economy Holleys, so there's no adjustment nor sight plug.

Pulled the needle and seat, cleaned everything up, and put it back together.

Everything is good now!

Thanks to everybody for the suggestions!

 

Be sure to check your oil. If the carb was flooding, the oil could be contaminated with gas. As for electric fuel pumps; is it wired through a safety switch?. Most guys just wire them to ignition power,and if the engine stops,the pump can fill the engine with gas. Holley has a switch (12-810),that tees in with the oil pressure sending unit. When oil pressure drops below 5psi, it shuts off the pump.

 

Have to agree with DB429SCJ...
Fuel in the oil= no bueno for the bearings.....
(that you just replaced)

 

Oil is good! No smell of fuel, and the thickness and color seem good

when i pulled the plunger (needle?) from the seat, I wiped the (rubber/teflon?) tip on a t-shirt and it left a mess on the shirt. Also some fine powder in the bottom of the bowl. Cleaned everything out with spray carb cleaner, and all is good!

while I had the carb off, I verified that the throttle plates close on the transition slot to a square, as I've read many times on this site. Also changed the rear fuel filter while thinking about it

took the truck for a drive, and it's got great throttle response, excellent acceleration, no noticeable stumble nor bog on acceleration, kick-down works great, blipping the throttle makes the truck lurch-everything I expect it to do, and nothing I don't

wasnt able to take it to WOT, but it was still accelerating strong at 75. Hitting passing gear at 50ish raised the RPMs to approximately 3500, accelerated to 65ish and it shifted back into third and dropped the RPMs to 2500ish. Around 2700/75 mph when I backed off

rough observations, of course, as I was driving, watching for cops, watching the speedo, and watching the tach...all in completely different places

 

I don't know if you have ever used them but we send off samples to Blackstone labs on some of our older restoration jobs to see if we're going to have to tear into the engines. Owners of some of the rarer cars prefer we do not tear into original engines. For less then 30 bucks you can have a useful analysis of how your engine is wearing. I don't recall if this is a engine you recently went into but just a FYI.

 

Thanks for the good info!

I bought this truck, the 79, from Crackhead Bob. He said he bought it from the original owner, and that it'd been in California it's whole life. Seems reasonable.

When I bought it, it had an Offy intake that didn't seem to fit correctly. It also had several missing/broken bolts. The carb heat cover was also loose. When I was driving it back from San Diego, I think it blew a head gasket

Anyway, I pulled the heads and had them rebuilt. I installed an edelbrock Performer intake and a Holley carb. It's been very happy since.

The truck carries very good oil pressure. I've not torn into the bottom end.