[67gtospud]

After sitting for 1-2 weeks without starting my car takes quite a bit of time to start. It takes about 45-60 seconds of cranking with a few seconds break every 10 seconds or so. If I start it one day then the next it fires immediately.

I have a rebuilt 400 with a lunati 276/284 hft cam and edelbrock dual quad intake with matching dual Carter 400cfm carbs. Choke only on the primary. 1/2" fuel line from tank to RobbMc 550 mechanical pump and 1/2" fuel line from pump up to the carbs where it Tees off to 2- 3/8" lines

[tom s]

All my cars are like that with our modern gas.One cars has a elect pusher and it always fires right away.I guess it evaporates in the bowls.Tom

[Craig Hendrickson]

Originally Posted by tom s

All my cars are like that with our modern gas.One cars has a elect pusher and it always fires right away.I guess it evaporates in the bowls.Tom

'
^^^^
X2

The only solution. Also helps with vapor lock on really hot days.

[67gtospud]

Alright, I guess I didn't know this was common. I've never driven a carbureted car before so I'm still learning. I do have a return line coming off my pump to eliminate possible issues with hot start or vapor lock. Maybe down the road I may look into an electric pump.


Off topic but when my car Starts it refuses to idle until the engine reaches 130-150 degrees. After that there's no idle issues. Is this a simple fix by adjusting the electric choke?

[Goatracer1]

How high do you have the fast idle set? And on which step of the cam? Not curb idle.

[lust4speed]

Just another verification of the problem being today's fuel. I've added a small pulsating pusher pump to get gas up to the carburetor before hitting the starter. The type of pusher pump is important since the vane and gerotor pumps won't allow fuel (or at least not much fuel) past the vanes. The pulsating pumps just have check valves and don't offer much restriction with their flow-through design. I've got mine on a toggle switch, and for normal running I turn it off after starting the car. If I'm playing around and need additional fuel, I leave the pump on to supplement the mechanical pump.

We've also went to the trouble on a friend's higher horsepower engine to use a large vane pump with a bypass circuit complete with check valve around the pump. Even with the bypass circuit, he was running out of fuel with the McRobb 500 mechanical pump if he didn't leave the pusher pump running at the drags. This was on a 4,050 pound car (with driver) running 11.70's. Plenty of fuel with both pumps running.

[67gtospud]

Originally Posted by Goatracer1

How high do you have the fast idle set? And on which step of the cam? Not curb idle.

I'm not really sure where it wants to idle until the engine warms up some sine I have to faster the pedal the entire time. Once around 130 degrees idle is roughly 1000 rpm .

[steve25]

Both Carbs need a choke as there is no other way to get the more than complete reversal of the air to fuel ratio that a cold motor needs to fire over on !

This is also why fuel injected motors have a idle air bypass valve and other cold start features .

I used the choke in both of my Carter Carbs on my blown 455 and even after sitting for 3 months at times and with today's gas , would in 25 degree temps would kick right over in 3 revolutions .

Extended cranking like that will greatly reduce the life of the starter in short order!

[Birdguy]

I also discovered that it took much too long for my Firebird (original mechanical fuel pump) to fire off after sitting for more than a couple of days. The solution for me was to install a small fuel line check valve just prior to the carburetor. The difference was dramatic. Now, even after sitting for 2-3 weeks or more, it fires up like a champ.

[Schurkey]

Originally Posted by 67gtospud

I'm not really sure where it wants to idle until the engine warms up some sine I have to faster the pedal the entire time. Once around 130 degrees idle is roughly 1000 rpm .

You have choke problems.

Originally Posted by Birdguy

I also discovered that it took much too long for my Firebird (original mechanical fuel pump) to fire off after sitting for more than a couple of days. The solution for me was to install a small fuel line check valve just prior to the carburetor. The difference was dramatic. Now, even after sitting for 2-3 weeks or more, it fires up like a champ.

Some folks use the "safety valve" fuel filters in the carb housing. Common for Rochester carbs, in both short and long styles. Not sure about Holley or or other carb brands.

The problem is that the check valve(s) in your fuel pump are faulty. If your fuel pump check valve(s) worked (actually stopped the fuel from flowing "downhill" back to the fuel tank) you wouldn't need the aftermarket check valve.

[tom s]

I watched Sean at SMI when installing a new carb on a engine squirt carb cleaner on the vent in the carb.Enough to get a pump shot.Fired up right away.Been doing it when my cars set for more than 10 days.Tom

[Skip Fix]

I see this worse on my Q jet and AFB style carbs as accel pump is in the main bowl. Holleys it is separate and the lowest spot on the bowl.

Also having an electric to prime it helps a bunch.

[tom s]

IN the vent in the carb!Tom

[Schurkey]

Originally Posted by tom s

I watched Sean at SMI when installing a new carb on a engine squirt carb cleaner on the vent in the carb.Enough to get a pump shot.Fired up right away.Been doing it when my cars set for more than 10 days.Tom

Originally Posted by tom s

IN the vent in the carb!Tom

I would be very reluctant to spray aerosol carb cleaner onto rubber/leather/Viton parts.

Gasoline down the bowl vent, or aerosol carb spray into the primary venturis. Yup, works good.

I wouldn't want to do any of this every time the vehicle was un-used for a week or more. That frequency argues for an electric fuel pump.

[tom s]

I try not to let any of them go even a week without starting.Since my rotator surgery 7 weeks ago it's a little harder.Tom

[tom s]

And I'm sure if it worse than the gas were putting in them here in CA!

[DevoBuzz]

Originally Posted by Birdguy

I also discovered that it took much too long for my Firebird (original mechanical fuel pump) to fire off after sitting for more than a couple of days. The solution for me was to install a small fuel line check valve just prior to the carburetor. The difference was dramatic. Now, even after sitting for 2-3 weeks or more, it fires up like a champ.

Where did you get this fuel line check valve from?

[Schurkey]

Originally Posted by tom s

I try not to let any of them go even a week without starting.Since my rotator surgery 7 weeks ago it's a little harder.Tom

I park my cars until I need to use them, or feel like working on 'em. Sometimes that's six or eight months.

[67gtospud]

[QUOTE=Schurkey;5561530]You have choke problems.


Would I need to rotate the choke coil towards the richer side or leaner side? I feel like richer side would be right but then again I'm usually wrong

[Schurkey]

Originally Posted by 67gtospud

Would I need to rotate the choke coil towards the richer side or leaner side? I feel like richer side would be right but then again I'm usually wrong

http://www.chevelles.com/techref/Adj...tic_Chokes.htm