It wouldn't run for more than a few seconds last week. I blew out all the fuel lines today, and got her started. She won't start unless half-choked. Then I have to kind of play with the choke, and pump the accelerator to keep her going.
Mind you, this is a Carter 1v YF manual choke carb.

The carb is good, it ran fine on the 223 that was in the truck previously, so I thought it would do the same on the 300. I have a vac gauge, and just put it on the vac line, and adjusted the screw until I got the max pressure on the gauge. (on the 223)

You think it's a vacuum issue, or a carb issue?

 

I'll start the conversation and others will join.

The 300 engine is very sensitive to vacuum leaks. Make certain all unused vacuum ports are covered. Check the two nuts on the bolts which secure the carburetor. It is not uncommon for the intake manifold gaskets to be a source of vacuum leak [just after an engine swap or repair]. With the engine running [might need a friend], carefully spray carburetor cleaner or use an unlit propane torch slightly opened and spray around the base of the carburetor as well as the block where the manifolds attach. If the idle speed changes, you have found a leak.

Hey, I just looked closely at your photo... I believe your ignition wiring is incorrect. For the 300/4.9L, the firing order is 153624. I cannot follow the wiring for 4,5 & 6 [due to cropping of photo, but can see that #3 does not appear to follow #5.

 

"You think it's a vacuum issue, or a carb issue?" Yes. It could be a vacuum issue with the carb too like a worn throttle shaft.

X2 on what 1986F150six said. Check for vacuum leaks and firing order. IIRC an 82 would have the vacuum advance hooked up to a "timed" port on the carb and not to a full manifold vacuum source. A Carb from a 223 might not have a "timed' port.

 

Here's a quick video of the behavior:


Hart, I was afraid you would say that. I still have the original Carter with the electric choke that came with the engine...I may have to slap that on there and see what I get.

 

From the video, the firing order looks correct. Is there any chance you are 180 degrees off?

Engine looks nice, by the way!

 

Thanks for the compliment 1986!

I don't think the dist is 180 off, i haven't removed it since I got the engine, and it ran when pulled according to PO. I will check it to make sure.

I'm going to go ahead and put the original carb back on it, but...I didn't mark it or take any photos when I pulled it, I wasn't expecting to use it...so I have a couple questions about what goes where:

1. some connection to the electric choke that has been removed...I can plug this hole, right?


2. Not sure what connects here....I want to say it had something to do with emissions, so that can be plugged, right? (all the emissions stuff has been removed.)

3. Vacuum line from the distributor goes here. (right?)



4. Pretty sure this is emissions related, can be plugged, right?

5. I want to say #5 is the fuel line....



Thanks for all your help!

 

The open port in the first photo was where hot air was drawn in to heat the bimetallic spring to control the choke opening. Since you are using a manual choke, you will be okay to plug it. In actuality, the carburetor was designed to have a slight vacuum leak, due to this function. The "jetting" will be affected, but in the real world, it can be run when plugged.

#2 is ported vacuum

#3 is manifold vacuum

#4 is fuel

#5 is vent [for bowl]

Before installing the carburetor, check the 4 (?) screws on the bottom of the bowl. They tend to loosen over time and now is the best time to check. Be sure to use new gaskets for the base of the carburetor. Gaskets take a set and you might have a vacuum leak even if only recently installed.

 

So, I was taking the existing carb off, and getting ready to put the original carb on it, when I found something...

For the record....I am an idiot.

Remember: possible vacuum issue, not pulling fuel, won't idle, maybe sucking air somewhere....

do you see the problem in the pic?



My neighbor (he's a mechanic) and I had a good laugh about it.

I'm gonna go ahead and plug that hole...then see what happens.

 

I was going to say.... it does "start", just doesnt continue running. I was suspecting weak fuel flow but a very lean condition would also be the culprit as you have discovered.

 

Golfers would say, "a hole in one!"

That is where the vacuum tree is normally located.

 

I love finding things like that! You may feel silly for a moment but on the flip side you have such a glaringly obvious problem that you aren't left wondering.
The difference with that plugged will be immediate.

 

As expected, that was it. She fired right up and started purring like a girl with a brand new diamond.

Thanks to all for the guidance...I do feel silly, but on the bright side, it was a 5 minute fix for a 2 week headache.

 

Don't feel silly... we all had an opportunity to exercise our brains and for all that participated, there were likely many more "watching" who have learned as well! By openly sharing, you have done all of us a service.