Idle RPMs

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Jim Beam
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Idle RPMs

#1 Post by Jim Beam »

1963B Coupe Normal; running Weber 40s with Bosch 050 distributor. Suddenly the idle speed reduced itself to about 300 RPMs. Motor quits at that RPM. Wondering is there is a relatively simple adjustment to be made to increase the idle speed to around 750 RPMs?
1963B (T6) Coupe
1987 3.2 Carrera
1985 FJ60 Landcruiser
1993 Miata

Dick Weiss
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Re: Idle RPMs

#2 Post by Dick Weiss »

Each carb has an stop screw which adjusts the carb's idle RPM; For an balanced idle, you must use a Unisyn, or Sychronometer (gage).

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Doug McDonnell
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Re: Idle RPMs

#3 Post by Doug McDonnell »

But if everything was fine with stable idle and you suddenly developed this then there is a reason to be found. Distributor plate was sticking for a long time and finally went back to base? Doubt it. Maybe a partially clogged idle jet? More history would help.
1965 356C 2000 BMW 740i Sport 1967 Honda CL77 There is never enough time to do it right, but always enough time to do it over.

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Neil Bardsley
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Re: Idle RPMs

#4 Post by Neil Bardsley »


Tim Berardelli
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Re: Idle RPMs

#5 Post by Tim Berardelli »

Jim,

Check your dwell-as the rubbing block on the points wears the dwell increases and the timing becomes retarded-a .004 reduction in point gap will change the timing by 3 degrees.

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Ron LaDow
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Re: Idle RPMs

#6 Post by Ron LaDow »

I keep beating this horse, but it's sill not dead:
DO NOT adjust the carbs first.
Do a complete tune up in the proper sequence, and adjust the carbs to suit what the specific values (valves and ignition) want.
Ron LaDow
www.precisionmatters.biz

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Neil Bardsley
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Re: Idle RPMs

#7 Post by Neil Bardsley »

Ron LaDow wrote:I keep beating this horse, but it's sill not dead:
DO NOT adjust the carbs first.
Do a complete tune up in the proper sequence, and adjust the carbs to suit what the specific values (valves and ignition) want.
That is what the link I posted suggests :)

Tim Berardelli
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Re: Idle RPMs

#8 Post by Tim Berardelli »

Jim,

Did you ever solve your low idle problem?

Jim Beam
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Re: Idle RPMs

#9 Post by Jim Beam »

Thanks for the responses. Car has been sitting in the garage and I haven't had time to attend to it. I really do not have the skills and am attempting to get it into my wrench for a couple of issues, the low idle RPM being one of them. In the meantime, I am wondering whether I can adjust the carb linkage to accomplish a higher idle RPM? This would be only a temp fix until the issue can be addressed further. Thanks again.
1963B (T6) Coupe
1987 3.2 Carrera
1985 FJ60 Landcruiser
1993 Miata

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Ron LaDow
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Re: Idle RPMs

#10 Post by Ron LaDow »

Jim,
If you bandaid it, it just makes the proper adjustments more difficult. Why not just get it to him and let him to the correct process?
Ron LaDow
www.precisionmatters.biz

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Wes Bender
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Re: Idle RPMs

#11 Post by Wes Bender »

+1 on what Ron says. You would be adding a complication if you adjusted the linkage without knowing that it was the problem. You indicated the idle suddenly dropped to the 300 range. I'd let the wrench know everything you've told us and let him find out what took place. I'm assuming that your wrench is well qualified in these fine cars.
Some days it's just not worth chewing through the restraints.....

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