Carb hot start questions Options

[mb911]

My car runs really well. Cold starts great. Has phenolic spacers etc but after I shut it off I have to have the throttles open at least half way and crank for 5-10 seconds to start. If I don't open the throttles then it will sound like timing is to advanced but clearly is not and it will stumble until it clears out.It has to be some excessive fuel getting down the throats somehow? What to check? Floats sticking?

[brant]

Most likely fuel is still over-boiling. Despite the phenolic spacers

[mb911]

Most likely fuel is still over-boiling. Despite the phenolic spacers

That is strange still did it this morning on my run over to cover the boat. Never even got to 180 degrees on the drive there and it was only about 72 this morning.

So what are my options?

[914Toy]

Most likely fuel is still over-boiling. Despite the phenolic spacers

That is strange still did it this morning on my run over to cover the boat. Never even got to 180 degrees on the drive there and it was only about 72 this morning.

So what are my options?

1) Start by turning the ignition on and wait about 20 seconds (time for the fuel pump to fill the float bowels), 2) press the accelerator pedal slowly to the floor (accelerator pumps squirt fuel down the intake) then release it, 3) engage the starter motor, 4) then press the accelerator (1/3rd) after the motor is turning over. Works for me!

[mb911]

Most likely fuel is still over-boiling. Despite the phenolic spacers

That is strange still did it this morning on my run over to cover the boat. Never even got to 180 degrees on the drive there and it was only about 72 this morning.

So what are my options?

1) Start by turning the ignition on and wait about 20 seconds (time for the fuel pump to fill the float bowels), 2) press the accelerator pedal slowly to the floor (accelerator pumps squirt fuel down the intake) then release it, 3) engage the starter motor, 4) then press the accelerator (1/3rd) after the motor is turning over. Works for me!

For hot engine? I have zero issues cold. The engine is clearly flooding in a hot start situation. I believe it's perculation or a float sticking, needle and seat. But with the carbs being 1000k fresh for performance oriented I need to zero in on which one I should concentrate on.

[sixnotfour]

http://forums.pelicanparts.com/porsche-911...tml#post3774156

[sportlicherFahrer]

Floats and fuel pressure are always good to verify.

What fuel are you running? I tend to have problems if I run the regular stuff at the pump that has ethanol in it. Ethanol free performs much better across the board in all of my cars/trucks that have carburetors. Harder to find and pretty spendy these days, but worth it in my mind for stuff that isn't my daily driver/commuter.

[mb911]

Floats and fuel pressure are always good to verify.

What fuel are you running? I tend to have problems if I run the regular stuff at the pump that has ethanol in it. Ethanol free performs much better across the board in all of my cars/trucks that have carburetors. Harder to find and pretty spendy these days, but worth it in my mind for stuff that isn't my daily driver/commuter.

I run 93 non ethonal.

[mb911]

http://forums.pelicanparts.com/porsche-911...tml#post3774156

I will check that out for sure.

[slivel]

Is your hot start problem new or has it existed for a long time? If new, has your fuel consumption also increased? Once hot and re-started, I would pull the air cleaners and look down into the carb throats. If you see fuel dribbling visibly at idle, then you have a float problem. Possibly a float with a leak so that it is no longer fully dry inside or possibly a stuck float needle, or lastly just a fuel level that is too high in the bowl.

I also had my 46's overhauled by Performance Oriented and he did a fantastic job, but I did reset my fuel level a little bit when I got the carbs back (this was a long time ago - 10 + years). My car always cold starts reluctantly when the car has sat for a long time (weeks) or if the temperature is cold. I have had to use starting fluid a time or two when at the track and overnight temps dropped into the 30's. Once hot the engine always starts immediately.

Lastly, check your fuel pressure. I run 3.5 psi.

[Mark Henry]

I would also say float level and fuel pressure. I made a set up to do my float level on the bench, although not hard I hate doing the deed in the 914.
If I get time I also have to clean out and check my carbs, I got three years since last service. Likely it will be an in car job. (IMG:style_emoticons/default/rolleyes.gif)

[rhodyguy]

After a prolonged drive open the engine lid when you're parked. It might take a few pumps and start tries. When the cooler fuel gets to the carbs things calm down. Do not grind away with starter. Let the pump and carbs do the work. Or, put an FI cam inside and return to a fuel injection system outside. A or B.This is a case where installing a pressure return line is not going to help. (I put phenolic spacers between the carbs and intakes too)

[mb911]

So nothing has changed this is sort of new as far as a symptom but Jake Raby spoke up and said it's because of summer blend fuel. It kind of makes sense as I just refueled.