[7dcrzr]

My SB350 with a carter carb will not start when it is cold until I spray a shot of starting fluid down the throat then it fires immediately. I can crank it continuously pumping the throttle and nothing until the starting fluid. Once the motor begins to warm up it starts flawlessly after shutting down. I also checked the spark and it looks good.

Does anyone have any idea what is wrong? I am far from being a motor guru, but I cant imagine a choke not working properly would cause the engine to not start at all. I can see it causing to run poorly... but completely not starting seems odd to me.

Any help appreciated!

Thanks
7DCRZR

[56Maynard]

I bet your mixture is too lean to support combustion while your motorrrr is stone cold. Tomorrow, turn your key one click to the right (dont engage starter) just one click to accessories, and floor the throttle once and hop right out and look at the choke plate position over the primaries. If it aint closed, visually inspect the choke linkage for damage or dirt and confirm that it is hooked up. If your choke linkage looks good, walk to the passenger side of the engine compartment and look at the carb, you'll notice a round black cap thats about 1 1/2" across and has three screws around the diameter. If you look close, you will see arrows and the words "< LEAN" "RICH >" take those 3 screws loose (loose not off) and turn the black housing clockwise towards RICH until the choke plate drops shut. Now hop back in the car and start it. Let er warm up and confirm that the choke opens back up as the motor gets warm. This will likely take some trial and error but it aint a big deal. Dont mess with any other adjustments and the black knob only adjusts the choke and nothing else.

[Brian_B]

Is it ok to hijack the thread for a second?

I am having basically the same problem with my 56 f-100. When its cold outside it refuses to start. On warmer days it does, but not easily. If you get it started and it warms up it runs well. I can drive it all over and start as needed.

Do you think it might be a similar problem?

Its a stock 272 y-block with a holly 2100 carb and a manual choke.

thanks,
Brian

[joe350s10]

does the vehicle have a choke? is it manual or electric?

Check and verify that the choke is operating as it should first.

Also, make sure the carb mix is right.

If the motor is spinning over nice and strong, the problem should be either the mix or the choke setting.

[dadsgp]

Yes Choke is critical to cold starting.

[tnoftsger]

Also, check your pump shot. Look down the throat of the carb, be careful, do it with the engine off, and see if the accelerator shot is pumping gas. This pump primes the engine with fuel for cold starts and to correct the lean condition during low vaccum. That is why we pump the accelerator for cold start, not to mention to set the choke.

[7dcrzr]

Thanks for all the replies and ideas, I am at work today but tomorrow I will go ahead and give it a try. I will keep you posted.

Fman

[7dcrzr]

It definitely helped the problem by adjusting the choke. Still a little tempermental and requiring a lot of pumps on the throttle to start but a definite improvement.

Thanks again for all the input...

[sbchevfreak]

Originally Posted by 7dcrzr

It definitely helped the problem by adjusting the choke. Still a little tempermental and requiring a lot of pumps on the throttle to start but a definite improvement.

Thanks again for all the input...

Look for vacuum leaks. Cranking vacuum is only 3-4 in/hg, so any leaks will drastically reduce choke effectiveness.

[IanRiordan]

Probably not the fault on the sbc, and DEFINATELY not on the y - block. In the past I found that a blocked carbon cannister wouldn't vent and actually pushed fuel out of the bowl and back into the tank. Took a while to find first time, just park it at night and disconnect the float bowl vent hose. If it starts easy next morning replace the cannister.

[Mean@MeanMother]

1-25-06

NOW: Gasoline (Approx 81 - 83 Octane) Is Made Up Corn Fed Using House Hold Cleaners Kick Up Octane-All At $3.00 Gallon!

BACK: Then My 1968 Corvette Made Run 118 Octane-You Could Pull In SUNOCO Pump Dial In Any Octane You Need Use!

Reset Any Choke Auto (Clean It) Factory Specs Or Mech. Check See If Closes!

Vacuum Leaks --Carburetors Warp From Engine Heat, (Concave -Convex) Gaskets Shrink Once Running Gaskets Expand From Heat Seal Cracks+Gaskets,i.e. Might Consider Switch To Holley Carburetor Easier Maintain + Rebuild!

Old Age, Heat, Todays New Parts Made Cheaper Esp. Carburetors Made Tawain From Cheap Pot Metals--

Hell Only Knows--Back Then--My Brand New 1968 Corvette Tr-Pwr, With 2000 Miles Speedo_

Winter 20 Below Zero, End Carbs Metering Plates Warp From Engine Heat Filled Engine Up With Gasoline--GMC Reps Did Not Know Until I Told Them What's Wrong + They Don't Care Just Wanna Sell You New Cars & Reap Benefits Of Its Greed...

RE: HARD COLD STARTS--I Just Reset Winter Auto Choke 68 Corvette 5 Different Times--Factory Calls .260- COLD--I Finally Set At .250-COLD, Use Only Chevron+ Octane Tablets!

But, I Have 12:1 Heads + MSD Ignition + Champion Platinum Spark Plugs-- I Even Reset Timing @ 10 Degrees @ 1000rpm-- All This Helps Make It Not Only Get Up Haul A*s--Run Right--- But It Starts Faster After 3 Days Parked!

Always Let Your Engine Car/Truck Warm Up 3/5 Minutes Before Drive--It Will Add Life To Engine--Todays Oils Thin Out Due To Many Additives In Oil + Cheap Gasoline Washes Oil Off Cylinder Walls...

Vincent Auto