Carb issues possibly fuel pump carb advice needed

[jakeperry]

Hi guys I am having a problem starting my ole girl up. Work has taken the most of my time and haven't had much time to run my bronco. The bronco is a 302 stock and stock carb. She has always cranked better if I would crank it everyday and has typically been been a little stubborn if it was a couple days between runnings. Anywho the fuel bowl is empty. And I can't get fuel to it although I have not poured fuel in it. So is it a carb problem or a fuel pump. I'm leaning towards fuel pump. I recently rebuilt the carb this spring although I was never pleased w it so I'm thinking about going w the holly avenger 470. Thanks in advance gentlemen

 

[jckkys]

If your 2100-2150 were leaking, it would have to be from the power valve or accelerator pump. That's unlikely since a bad power valve won't let the engine idle and the accelerator pump is in the front where a leak is obvious. Your fuel in the float bowls is just evaporating. A Holley, or any other carb, will do the same thing. Just start it every couple days. An insulating carb spacer helps. Mine has 4 thick paper types. I can let my AFB sit for 3-4 days and start it with 1/2 second of cranking. In a week it will dry up, and need to be refilled by cranking. The original 2 bbl will run better than a new Holley unless it needs repair or rebuild, with proper adjustment in both cases.

 

[Dapper Dan]

Well Jake here is my two cents on the deal. The 2100 2150 is a bullet proof carb no doubt about it. Ford spent millions developing the autolite carbs to be troublefree, and for the most part they are. IF you go to and aftermarket think small as you are like a 470. So many people I deal with wind up with too big a carb. little 302's are happy with 5 or 600 cfms. As for your issue your having number one is evaporation as above. Keeping the carb spaced from intake heat is always the best option. Second is what octane of fuel are you running? The 87 nowadays even 89 just goes up in smoke quick. That being said you may look to another fuel provider or station or octane level of fuel. Fuel pumps can let fuel flow back however that is tricky cause also the pressure will have to drop in bowl and bowl level will have to drop to open the float. Not out of the question though. So in closing I like the autolite carbs and think its a fine choice for you. If you 2100 is fairly fresh leave it on the truck. If aftermarket stay small. Second try changing your fuel quality and provider this may resolve your issue. Finally you may choose to install a new pump for possible diaphragm check valve failure. If you do replace pump do not buy a cheap $20 dollar parts store one. Try to find a carter (what ford used origionally) from summit or a better quality aftermarket pump. Wow I am sorry for getting long winded talking out load........:-X

 

[jakeperry]

Hey guys thanks for the advice. My problem w the cranking is that the fuel bowl does not refill I took the top of the carb off and tried cranking while looking(quiet a stretch) but the bowl remains dry. So wouldn't it be the fuel pump ? I think the stock carb is very reliable I just need to learn the tuning even when it's running good it's still jumpy ( if that's a proper explanation) thanks again for the replies

 

[broncnaz]

Most likely its the fuel pump. You also need to check the rest of your fuel lines to make sure they are in good shape. If they are cracked they could be sucking air or if they are kinked then fuel wont get pulled thru. Also change the fuel filter. Pumps are fairly cheap. but even so these other things can be part of the problem as well.
I usually have no issues starting my stock 71 after it sits for a week longer than a week and it does take a little more cranking. My 73 has no issues but its not stock either. I run a electric pump on it

 

[WheelHorse]

Hey guys thanks for the advice. My problem w the cranking is that the fuel bowl does not refill I took the top of the carb off and tried cranking while looking(quiet a stretch) but the bowl remains dry. So wouldn't it be the fuel pump ? I think the stock carb is very reliable I just need to learn the tuning even when it's running good it's still jumpy ( if that's a proper explanation) thanks again for the replies

You're 100% positive there is gas in the tank regardless of what the gauge reads?

 

[jakeperry]

You're 100% positive there is gas in the tank regardless of what the gauge reads?

wildhorse lol honestly i havent stuck the fuel tank but i topped here off on my last ride and only had about a 45 mile ride that day so should be plenty left in her unless i was robbed !

 

[WheelHorse]

And you're sure the little fuel filter in front of the carb isn't plugged solid?

 

[blubuckaroo]

I'd rather troubleshoot than just start replacing stuff. Otherwise you can just end up chasing your tail. If you feel that it's not getting fuel, and the filter is ok, I'd first use compressed air in the gas tank. (just a little pressure) Any leaky fuel line or selector valve suction leaks will become obvious. Next, remove the suction hose from the fuel pump. Pressure in the tank should create a good stream of fuel from the hose if you don't have a blocked pick-up or other blockage. Now that the suction hose is off the pump, connect a vacuum gauge to the pump and crank the motor over. Most vacuum gauges have a fuel pump scale for that. I love this stuff as long as it's someone elses car.
Keep us posted

 

[jakeperry]

Guys thank a lot for the advice I appreciate the time and detail. Got off work early and checked the filter, it was good. There is fuel gettin to the fuel pump but not to the filter on the carb. Looks like I'll be replacing the fuel pump in the next day or two. Thanks again

 

[CopperRanger]

You can disconnect the fuel line at the pump going to the carb, have someone crank it over and see if your getting gas out of the pump, if nothing is coming out I would replace the pump.

 

[707Bronk]

If you go with a TA, go with what the manufacturer designed for SBF, which would be the 670. If you go with the 470 it will likely be too rich, and if go with the largest one it will be too lean. Many people call up Holley reporting problems with the 470 and Holley then ships them out a 670 because it is designed for use with 302s and 351s.

As far as not getting fuel, try disconnecting the fuel line and seeing if it will pump fuel into a bucket, and its a good idea to put an inline fuel pressure gauge just before the carb so that you can visually see if fuel is getting to the carb.

There might also be an screen filter at the inlet of the carb that often gets clogged and overlooked.