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yetiSIII
07-12-2010, 07:37 AM
Hi, I'm a proud new owner of a 76 siii, with a weber carb. At start up it will sit and idle perfect, but after about 10 mins of driving it wants to idle so low to almost a stall. I pulled the choke half way today at a light going to work and it idled perfect. I've replaced the mech fuel pump with a electric, and used a return line fuel filter to stop the vapor lock. Does this sound like a mixture problem? timing?
Glad to be a rover owner again!
Cheers
Andrew IIA
07-12-2010, 08:34 AM
Congrats on your (new) SIII !

This sounds relatively normal; try turning the idle speed adjuster screw on the carb up a hair until it idles comfortably when hot. (not sure where that is on your carb, sorry).

Enjoy
yetiSIII
07-12-2010, 08:41 AM
Thanks Andrew, some how this beast is a money pit/ headache. But it still keeps a smile on my face! I'm going to try that after work today, I also noticed that my vaccum advance rubber boots have some cracks in them. going to replace that too.
Does anyone have a straight forward step by step to tune a weber?
Andrew IIA
07-12-2010, 02:12 PM
Does anyone have a straight forward step by step to tune a weber?
Try this: http://www.piercemanifolds.com/category_s/313.htm

Someone else here with a similar 1bbl Weber should be chiming in soon.
usadventureracing
07-12-2010, 05:12 PM
I just installed a new weber carb and pretty much did what the link that was added to your post stated. It is running much better than it did but I am going to print the PDF and follow it again to fine tune.
yetiSIII
07-13-2010, 07:27 AM
Yeah, I'm going to do the step by step too, hopefully today. Yesterday I just adjusted the speed screw and it seemed to help a little bit, it's weird how I get the low idle only sometimes. I think I should check my timing first. Any tips or suggestions?
usadventureracing
07-13-2010, 09:43 AM
I was always told in this order to set points, then timing and then carb.
thixon
07-13-2010, 10:06 AM
Yeah, I'm going to do the step by step too, hopefully today. Yesterday I just adjusted the speed screw and it seemed to help a little bit, it's weird how I get the low idle only sometimes. I think I should check my timing first. Any tips or suggestions?
Don't forget to check all your linkage. You could have a worn out spring, or a sticky control arm somewhere as well.