Hard cold start

[Bluegrain64]

Hello everyone, I’m having a cold start issue with my Rochester 1 barrel on a 235 six. It’s a manual choke set up and fires up with a hit of the key when it’s warm. If it sits for overnight or longer, it cranks like crazy and won’t start without a shot of fuel or carb cleaner.

I go through the regular cold start procedure as with all my carburetor equipped vehicles. Timing is good, points are new and set, carb was rebuilt and I run non-oxy fuel.

This cold no start is driving me crazy!!

I’ve attached a picture of my truck, it’s my favorite rig I’ve had.

[jayoldschool]

I just added a manual throttle cable/knob to my 65 and it makes a cold start much easier. However, have you verified your accelerator pump is working? I rebuilt the carb on my 65 to make sure that everything was working well.

[vince1]

Beautiful prairie land you have out there and nice truck too.

If your fuel pump is good and the accelerator pump is good and your choke works good there is not much else except maybe put in an electric fuel pump, if just to get it primed. I'd try a fuel pump first though. It should prevent fuel from getting back to the tank.

[Bluegrain64]

Thanks for the nice compliment on the property and truck. I’m going to check the accelerator pump shot today. I know the previous owner did put in a new fuel pump. It’s just weird how it fires up instantly with a hit of the key when it’s warm. I was reading too that there may not be adequate tension on the spring that goes over the accelerator pump rod and plunger.

I’ll take a look at the shot of fuel when it’s cold and report back.

[Bluegrain64]

I checked the pump shot and I saw a pretty weak squirt. I could only see one, not sure if there are more? Did it a few times, and noticed it started to run out of the bottom of the carb near the base.

[geezer#99]

Sounds like you have enough fuel shot.
Maybe your starting procedure is at fault.
Are you the pump, pump pump the pedal until it sputters to life kinda guy or are you the two pumps and close the choke fully and poke the choke open a touch when she fires up kinda guy.
You might be flooding it if you’re the pump pump pump guy.

[Bluegrain64]

Originally Posted by geezer#99

Sounds like you have enough fuel shot.
Maybe your starting procedure is at fault.
Are you the pump, pump pump the pedal until it sputters to life kinda guy or are you the two pumps and close the choke fully and poke the choke open a touch when she fires up kinda guy.
You might be flooding it if you’re the pump pump pump guy.

😂 Ok I’m not going lie, I’m the pump, pump, pump, pump, pump, pump , pump close the choke, crank sputter, open choke, hold to the floor, pump some more sputter to life, hold throttle halfway until it clears out kinda guy.

If I do it the right way, it just sometimes briefly fires then dies right away.

[geezer#99]

Then give it one more pump and try again.
Is your choke blade fully closed when you try to start it?

[vince1]

You could try changing the rubber hose coming from the tank to the line. If it has deteriorated it could be sucking air.

It happens more than you might think. I knew of a new Ford diesel that was hard to start. The guy that finally fixed it pressurized the line and found a pin hole leak.

[Bluegrain64]

Originally Posted by geezer#99

Then give it one more pump and try again.
Is your choke blade fully closed when you try to start it?

Yes it is, I know that for sure.

[PGSigns]

Here is something to try. First look at the fast idle setup. Push the pedal to the floor, then while it is down pull the choke. Pup the hood and take a look to see if the choke is closed and the fast idle is actually working. Then try and see if it will start. If you have fuel running out the throttle shaft you are flooding it. Start procedure should be push the pedal to the floor, pull the choke out about 80% and let up off the pedal. Hit the key and it should light. I think you are hitting it way to many ties.
Jimmy

[jayoldschool]

Wait, choke should be OFF when I pump it cold? THEN pull choke? I always pull choke when I shut off truck and start it the next time like that (still closed from last shutdown). Have I been doing it wrong? Could my truck actually be easier to start when it has sat for a few days?

[vince1]

My technique for cold starting the 250 was this; full choke, pump pedal, crank a couple times, keep pumping, crank a couple more times and off she would go. The quadrajet on the SBC gets the same cold start procedure except that the choke happens by itself.

[franken]

Maybe check the accelerator pump squirts when cold. I'm thinking the bowl is draining overnight and no gas in the AM. Sorry if I missed a post saying this was tried...

[Bluegrain64]

Originally Posted by PGSigns

Here is something to try. First look at the fast idle setup. Push the pedal to the floor, then while it is down pull the choke. Pup the hood and take a look to see if the choke is closed and the fast idle is actually working. Then try and see if it will start. If you have fuel running out the throttle shaft you are flooding it. Start procedure should be push the pedal to the floor, pull the choke out about 80% and let up off the pedal. Hit the key and it should light. I think you are hitting it way to many ties.
Jimmy

Well I feel kinda dumb, but I tried the suggested method above yesterday and again today. It worked perfectly! I wasn’t doing the start process correctly. I was resorting back to my Quadrajet with no choke method. That required a lot of pumping and feathering and fiddling.

I pulled the choke, depressed the accelerator once, cranked and it fired/died. I then gave it one more shot of fuel with 3/4 choke and it fired right up! No more stabbing the gas pedal 20 times to start thinking it wasn’t getting enough fuel. I’ve got several old cars and they are all a little different for starting. Thanks everyone that offered their valuable insight. We’re good to go!

[jayoldschool]

I will try this today, and report back. My truck's been sitting for a week, and it has been below freezing each night. A good test. I need to use it tomorrow!

[jayoldschool]

Choke in, foot to floor. Pulled choke 3/4. Cracked throttle knob a bit. Started right up first crank. Who would have thought...