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2.0 wont run properly

I've just finished my build. Was a 2.0L S with T cams.
It now has dc30 cams and some higher comp Wiseco pistons.
It now pops constantly thru the carbs and to a lesser extent the exhaust.
I cannot get a stable idle and after a rev does not return to idle in a timely manner. Stays up around 2 to 3 k for a few seconds.
Idle mixture does not do much if anything.
Timing is set. Throttle linkage does not stick.
I did not go thru the carbs. They were Working.
Lyndon


Last edited by Lyndon302; 07-28-2020 at 04:16 AM..
Old 07-27-2020, 06:29 PM
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what? me worry?
 
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Congrats, you now bet to play"re-jet" that carb!
Intake pops...= lean

Exhaust pops.. rich..

You rebuilt an engine, changed operating parameters, and plopped the old carbs on..

Refresh the crabs... and fix the jetting..
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Old 07-27-2020, 06:37 PM
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Ok I have 52 ildle jets ?
Do I go to 55 or 60. Its really bad.

Last edited by Lyndon302; 07-27-2020 at 07:56 PM..
Old 07-27-2020, 07:03 PM
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It's a 914 ...
 
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Post your carb jetting specs - idles, mains, air correctors, emulsion tubes, venturis, etc. You'll get some opinions.

A wide band O2 setup will help you a lot.

Consider the possibility of air leaks at the carb/manifold as well.
Old 07-28-2020, 04:06 AM
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I have 135 mains. 52 idle.
With out pulling them apart again. I'm guessing they are std sixty eight 911 L sportomatic webers.
They are on the sixty seven S engine.
I have some sixty idle jets coming tomorrow.
Lyndon
Old 07-28-2020, 04:16 AM
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It's a 914 ...
 
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This is for the motor you've been putting together? High comp pistons, correct? S spec cams and heads? Edit - whoops, saw you answered that above
Old 07-28-2020, 09:16 AM
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Try clogged jets or passages or idle screws. What size venturis? Are the 6 intakes balanced via the air adjustment screws?
Old 07-28-2020, 08:14 PM
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The carbs were done on the old engine last year. With that it ran ok for a worn engine. But I still didn't have any real control on the idle mixtures.
I have never measured the chokes.
Lyndon
Old 07-28-2020, 09:56 PM
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Idle not returning could be the distributor. Turn the key off and back on again rapidly, when the engine is idling to fast. If the idle speed drops then it’s a weak spring in the distributor. Mine was doing that and Jerry Woods rebuilt the distributor. Runs perfectly now.
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Old 07-29-2020, 03:27 AM
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Is that to force the engine to slow thus returning the springs. It may have week springs as it gets its max advance well before 6000rpm
Lyndon

Last edited by Lyndon302; 07-29-2020 at 03:41 AM..
Old 07-29-2020, 03:38 AM
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Yes
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Old 07-29-2020, 06:11 AM
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I had 4 early 911's that the distributor advance mechanism was frozen.
Old 07-29-2020, 06:55 AM
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Initial findings. 60 idle jets in. Air screws out 1 turn and all is well in the shop. Should be fine to get it inspected so I can get rego and drive it.
The idle mixtures still do nothing ? The rest balanced well.
Lyndon

Old 07-29-2020, 10:21 PM
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