Ok I'm working on an 84 inline 6 223 for a friend of mine. Carb needs rebuilding bad and run like pure crap. I rebuilt the carb and cleaned the fuel system an even had it running beautifully when it was hot after I rebuilt the carb. Now The next day apparently I've lost fuel pressure I had to dump gas in the carb to get it to start. Any ideas? I swear it's leaking back to the tank but how? Bad fuel pump seal?

 

Maybe you stirred up so more debris and something is clogged.

BTW that's a 300 in a 1980. Last year of the 223 was '64.

Clogged filter, stuck float, clogged needle seat, there are all kinds of things. Also, dead fuel pump.

Will it run after you get it started with the gas in the carb?

 

Yeah after you pour gas in the carb and it warms up it purrs like a kitten. Thanks for the correction.

 

What's the status of the choke and idle adjustment?

That it runs once warmed up kind of kills the bad fuel pump idea--to a point. If you take it out and run it through the gears, best with a load, does it pull all the way or die out half way into second gear? A lazy fuel pump won't keep up with fuel demand in this situation.

 

I would disconnect the inlet at the carb and test fuel pressure and output rate.

Is this a feedback carb with an electric pump?

 

No this is the pump on the motor that runs off the crankshaft. I have no clue about the load its not in drive able condition. Needs brake job etc. ill try checking the pressure when I get back over there

 

84 was originally a feedback carburetor so he does need to pull codes and see what the computer thinks is going on.

I'm not but about 75% sure, but I believe even the feedback carburetors ran a mechanical pump on the 300.

The 223 is also one of the few inlines that Ford produced with the manifolds on the driver's side.

223 L-6:



Ford 300 L-6 (first year of production 1965, last year 1996):

 

Holy cow! Is that a tuned ram air system to get "on the pipe" at a given RPM, or just a cool (pun intended) way to get air into the cleaner?

 

Ok well def. saying its a inline 300. I'm almost certain this truck does not have the computer. Maybe but I know I ain't got a diagnostic tool to read it if it did. Could it the fuel just be draining back to the tank due to a air leak in the system some where causing the pump to lose its pressure that it's supposed to maintain for later starting?

 

You are correct [the feedback carb equipped vehicles did have a mechanical fuel pump].

 

If mine sits overnight too, I don't have any fuel in my line running to the carburetor. However, when you first start it up, you should still have fuel in the bowl that it could run off of until the pressure comes back up.

I've been worrying about gas going through the diaphragm in the fuel pump to my oil, but I've kept an eye on my oil level and such is not the case. Gas in the oil is mainly due to the fuel pump having a hole in the diaphragm (ergo, bad pump). So, I wouldn't really worry about the fuel draining back out to the lines or the tank or wherever. You've also got to remember, in relation to the tank, the carburetor sits higher up than the tank, and thus the fuel lines would act like a sort of P-trap for the gas. It'd drain back down from the line at the carburetor, some maybe back into the tank, and the rest sitting in the lines.

If your truck is computer controlled, which it should be if original, the ignition module should be under the dash behind the ash tray below the heater controls, and the carburetor should have a bunch of wires to it. The distributor will also not have any vacuum lines going to it, just wires.

I'm with Chris, I'd get the truck running, cut it off, then disconnect the fuel line and have someone crank the truck back up while you hold the line into a gas can or something to see what the flow might be like.

It still wouldn't be a bad idea to pull codes. Has any of the emissions equipment been tampered with?

X

Gary, if you ask me, I just thought it was a rigged up snorkel for the air cleaner. Something that would look purdy, perhaps. I doubt a "ram air" system would do much on the factory Carter 1bbl he has on that 300 anyway.

 

This is a valid thing to worry about, it happened to me:

https://www.ford-trucks.com/forums/7...crankcase.html

Remember to take into consideration a siphon effect, this is how my crankcase became filled with gasoline....

Truck was backed into my sloped driveway, *** end in the air. It's an F350 with a factory lift, making the midship tank higher than the fuel pump.

It sat that way all summer and didn't move, which was apparently enough time to fill the crankcase with gasoline.

 

I haven't noticed the oil level on my dipstick rising, and the motor spins over just fine and runs just fine, and my gas hand never goes down while it's just sitting (this over the course of the months its been sitting until it becomes road worthy). My truck also has only the mid-ship tank. I just assumed everything was okay.

I might just go ahead and add a new fuel pump to the list of things to replace.

So basically, the fuel going into the crankcase gives it a hydro-lock scenario if it has been going on for an extended period of time? Wow. I certainly want to avoid that.

Learn something new every day. Thank you!

 

No, fuel in the crankcase doesn't give a hydraulic lock. Only a hydraulic substance, like gas or water, in the cylinders can give a hydraulic lock. Gas in the oil dilutes the oil and kills its lubricity. Running oil with a lot of gas in it will cause significant wear and may wipe the cam lobes.

 

I was referring to hydro-lock type symptoms (Chris's 400 not being able to turn over with the crankcase full of gas and oil). But yes, I could see how gas could kill the motor if it decided to get into the bearings, cam lobes, piston walls, etc. for any extended amount of time.