Cold Starting issue 80SC with Carbs and Motronic

[Rich76_911s]

Hey guys sorry if this has been covered before I did do a search, but everything I found is really on CIS. Just to clarify this is a 1980 911SC with webers and a motronic ignition system.

I just bought this car and it is having cold starting issues. It takes 4 to 5 tries to get the car to start when it is cold. When starting I usually try to give the car some time to get everything up and running, then I turn the key. The starter goes but the engine never really gets going. Each consecutive try after that it gets a little closer to starting then on about the 5 try it gets going perfectly. I've tried depressing the gas peddle to help get it started and that really doesn't help. And it starts perfectly when it is warm. Is there something that I could be doing wrong? Could it be the carbs? I ordered a kit with all the gaskets ect from pelican to clean the carbs and it is on the way. They need it anyway as the car misses a little in the middle of the throttle.

Thanks for all your help.
Rich

[ianc]

I just bought this car and it is having cold starting issues. It takes 4 to 5 tries to get the car to start when it is cold

Heh. I've had this issue with every carburetted car I've ever owned. That's why I love FI so much.

Sorry to be a jerk and not much help...

ianc

[araine901]

It could be the tune of the carbs. Check the float height. It should start pretty easy just turn the key on to get the fuel pump going, turn the key and press the pedal about 1/4" and it should burp to life pretty quick.

[B D]

I would try letting the fuel pump run for 10 seconds to get pressure then press the throttle down three times and on the third time hold it down to start. Common procedure for Webers when starting cold. Also check your fuel filter, may be the source of the miss. Good idea to clean your carbs anyway and put on a new fuel filter after. Here is a great thread on tuning Webers, read what T Bird says.

Weber rebuild

[Rich76_911s]

Thanks a lot for the input guys I appreciate it. And thanks for the link to the tuning of the carbs. I just started searching for a thread like that. I'll try all the suggestions and see what happens.

Rich

[RoninLB]

Originally posted by Rich76_911s

. I'll try all the suggestions and see what happens.

your Webers don't have chokes so a routine non-911 carb start is different.

Find out what procedure works for you and use it as a baseline for the coming winter. Keep the revs above 2k till it warms up a bit. Part of this game is keeping your plugs as clean as possible. It's better on your plugs to slowly raise the rpms instead of whacking it repeatedly.

[Nitrometano]

Originally posted by B D
I would try letting the fuel pump run for 10 seconds to get pressure then press the throttle down three times and on the third time hold it down to start.
Weber rebuild

I have doing this process since 7 years I own the 911 and it starts fron the first try. I dont wait 10 seconds. I recognize by sound when the fuel pump fill the lines. I have a Carter electric fuel pump with Holley fuel pressure regulator and VDO pressure gauge.