Hard Starting 170

[Anonymous]

I have a 64.5 Mustang with a stock 170.No work has been done to the engine other than a carb rebuild and new exhaust manifold.
It is fine when its running and will start easy once it has been started and shut off but if I leave it for a few days it takes a while to get the gas to the carb.Is there a solution to this problem?
Any help would be appreciated.

Thanks
Ponyman

 

[Anonymous]

maybe a fuel pump is going ?

 

[pedal2themetal45]

I would check the following
Choke
Accelorator pump ( on the carb)
fuel filter
fuel pump
carb needing rebuilt

tim

 

[ludwig]

Try a Pertronix unit in the ignition. After the fuel and air delivery issues are leveled out, this will get a hotter, more reliable spark to the gas, especially on cold start where there is a big glug of fuel and relatively little air.
(Others are not sold on the Pertronix II unit. I find it just fine.)

 

[Anonymous]

I agree with atgreen1 sounds like fuel pump needs replaced. You also might want to check fuel lines for a pinhole leak wich also could be letting air in the line therefore not keeping the fuel pumped up in the line, just a thought.
Good Luck

 

[Guest]

Are you good with adjusting chokes? I had the same problem when I first got my car. Essentially, with an "engine cool" condition, molecules of air are more dense, and closer together. Just like oxygen molecules are further apart in an "engine hot" condition, which explains why it runs well when warmed up...its literally "warmed up, and so are the oxygen molecules, and that makes them more spread apart. Your carburetor is set up for an "engine warm" condition, and thats why they added a choke...More...

Thats what the choke is for, to balance the fuel to air ratio in that "engine cool" condition. Essentially, it lets less air in, or "chokes" the engine of air, to balance tahe air/fuel ratio, since the air is more densely packed by being cooler.

On a 1 bbl 170, the carb has a wire with a screw on it for the choke adjustment. You might think its not a big deal, but its huge, even with it running warm. Try adjusting it with the choke pulled halfway inside the car (the choke knob). Unscrew the screw to let the wire release, and the flap on the carb for the choke is moveable. Keep moving the flap, tightening the screw down, pulling the choke halfway, and pumping twice and trying to start. Do it again and again, and even make marks with a marker where it was before, until it starts properly in cool condition. Youll get it. That 1 bbl usually works best when the choke flap is letting only a little air in, a small gap, when the choke knob inside the car is at "halfway".

Im sure theres also some sort of gapper for the choke that you may be able to buy, since you might or might not be familiar with tuning the choke properly. They may make a special tool.

I disagree that it was the fuel pump. A bad fuel pump would make the engine run too lean under ALL conditions, hot AND cold. Especially under load, such as the highway.

Anyways, I did the choke after I got it, and it runs perfect with a half pull on the choke and two pumps. Mine ran like yours when I first bought it. Just tweaked it out. Its one of the reasons why I got the car so cheap. The guy thought there were serious motor issues. Lucky the barn didnt burn down before I got it or anything.

 

[645blitz]

I too had the same problem with a 1100 autolite carb in my 64.5 mustang with the 170. The first thing I did was drain the gas tank because the car sat for 5 years and I didn't want any old gas going through my motor. Then I put a pertronix set up in the dizzy and put on a new fuel pump and a mallory coil with 45, 000 volts. Started up really well, but after a year or so it wouldn't start so good. So to the carb--got a rebuild kit and adjusted the choke and my starting was improved. Some other things to consider are timing and make sure you have good vaccum lines from the dizzy because our load-a-matic carbs can be sensitive when it comes to vaccum. mine had a leak but that affected the idle more than the starting--so anyway I agree that the problem is probably with the choke, but I have aquired a good habit of thinking about the whole system--so start with the gas to lines--fuel pump(definately replace it if its old--a good fuel filter etc.

 

[Anonymous]

after few days, pull the air cleaner and dribble a little gas in the carb.

If it starts up, you have a weak fuel pump.

 

[Guest]

Try this too. Take off the air cleaner assembly. Have someone cover the carburetor with their hand while you crank it. Tell them to leave just a bit of space to get air through. If you pump it twice, crank it and it starts up while theyre doing that, definitely the choke. Your friend played what the choke would (or should) be doing.

You need less air when a car is in "cold start" condition, since the molecules of air are more densely packed in cold, thus giving more oxygen per cubic centimeter into your motor=air/fuel ratio incorrect=lean condition=wont start cold.

Try to let us know what youve done, what may have worked, where youre at generally, when you get a chance.

It could be any one of the things said on here, but I start troubleshooting with the easiest, and less costly thing, and tuning a choke costs nothing.

 

[Anonymous]

Good idea, 2 ton.

Or, after several days, pull the air cleaner, and looking into the throat , pump the throttle linkage and see if any gas pumps out of the accelerator pump discharge nozzle. If no gas pumps out, your carb is dry.....and if it takes a lot of cranking to get gas into the carb again, the fuel pump has weak check valves.

 

[Lazy JW]

....Or, after several days, pull the air cleaner, and looking into the throat , pump the throttle linkage and see if any gas pumps out of the accelerator pump discharge nozzle. If no gas pumps out, your carb is dry.....and if it takes a lot of cranking to get gas into the carb again, the fuel pump has weak check valves.

Bingo!
No amount of choking nor super-duper spark intensifiers will do a lick of good if there ain't any gas in the carburetor Clue: it works fine unless "I leave it for a few days".
Joe

 

[Stubby]

You will probably find the solution from the pump to the carb but, everyone with an older car should check their fuel line from the tank all the way to the carb. The most commonly overlooked area are the rubber pieces of hose that connect the steel lines together. They tend to dry out and crack over time and either seap gas or let the pump suck air. When we brought home my son's 68 Mustang we couldn't resist cranking it. It started right up, that is a great feeling. Kinda like we resurected it from the dead. The third time we cranked it the fuel line had cracked a little right above the pump on the suction side. Fuel was squirting on the coil!! Car is under carport, NO FIRE PUTER OUTER IN SITE, They say the good lord watches out for fools and children (I often wonder who watches out for the wives and mothers while we are working on cars) Fortunately it did not ignite. It could have been terrible. Use good judgement when dealing with antique rubber. Heater hoses, radiator hoses, fuel lines, brake lines. Your life may depend on it!!!