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Posted by: SUNAB914 Jul 23 2012, 07:02 AM

Looking for some experience here on this issue. After quick or long runs my 1.8 duel carb is very stubborn to restart. It acts like flooding, but I have to pump gas pedal like hell to get it to start. When it is cold, three pumps and it starts right up and ready to go. Where should I start? Engine is rebuilt with close to 9K miles, hydro lifters, and I rebuilt carbs recently, when I rebuilt trans with Doc Evil and motor was pulled. It is really a pain to restart after a drive.
Thanks

Posted by: rhodyguy Jul 23 2012, 07:26 AM

warm fuel in the carb bowls/lines in the engine compartment is my guess, esp given the weather you've been having.

Posted by: 9146986 Jul 23 2012, 07:27 AM

An old school independent Porsche mechanic told me to start it with the throttle wide open.

Posted by: r_towle Jul 23 2012, 08:44 AM

Do you have phenolic spacers between the heads and intake manifolds.....and even the manifolds and carbs?

the motor actually gets hotter when you turn it off for a while as it becomes a heat sync.
this can make carbs tough to start if they get to hot.

Next time it does this, put your hand in there and feel the intak manifolds and feel the carb bodies...
If they are to hot to touch, you may need to examine putting spacers in to seperate them from the head better.

For the older 356's its 3 pumps, then wide open to the floor before even turning the key.
It takes some time and a few turn overs, but they start if you dont pump.

Rich

Posted by: SUNAB914 Jul 23 2012, 01:10 PM

r towle,

I have good spacers and nothing about that has changed since before I rebuilt them. I understand what you are saying, but this happens with in ony a few miles of running. If the car is cold, three pumps on pedal and it fires right up and ready to go. This is really wierd!

Posted by: r_towle Jul 23 2012, 01:24 PM

Who rebuilt them?
Jet sizes change?
Venturi sizes changed?

Did they use the correct accel pump gasket/plunger?
Odd, but many of the 40mm webers had different accel pump rubbers.
Old ones are NLA or really hard to find.
Each one has a different length plastic plunger.

Check the accel pumps to see if they are spraying correctly, (key on, fuel pump on, press the linkage to full throttle)

Really, prior to the motor running, the initial fuel is delivered by the accel pump.
So, it needs to be right.

the rebuild kits come with one size but it may not match your carb bodies.
Ask my how I know...I have the old italian webers...a beotch to find the right accel pumps for these...I have a baggie with five different parts in it...none were right.
finally found the right ones, but it took alot of hunting around.
Rich

Posted by: SUNAB914 Jul 24 2012, 09:37 AM

I rebuilt them and yes they are old italian webers. I will check what you said about accel pump.
Thanks Rich.

Posted by: r_towle Jul 24 2012, 09:39 AM

Art Thraen

Rich