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Joined
Nov 5, 2010
Messages
707
Reaction score
1
Location
Rochelle,Il
My Car
1971 mach1
:huh: Went to the track today these are the times I ran.

first run time run: 60' 2.142; 330' 5.401; 1/8 mi [email protected]; 1000' 11.664; 1/4 mi [email protected].

second run time: 60' 2.106; 330' 5.929; 1/8 mi [email protected]; 1000'

11.590; 1/4 mi [email protected]

third run elimination: 60' 20.069; 330' 23.995; 1/8 mi [email protected]; 1000' 29.649; 1/4 mi [email protected]

The last run went to wot from the light it sounded like a rifle shot when it backfired thru the carb. The car died but restarted right up.

Checked the plugs and they looked alright(like light chocolate milk).

The car ran good all day both driving to and from the track.

I am at a lose on where to go from here. Hope to have this figured out by saturday. They are having a powered by ford day.

Hope someone can steer me in the right direction.

Jim

 
Man! You really need to grab another carb and try to narrow this down. Starting with the carb is my recommendation. That way If it still does it we can look at timing, broken valve spring or wore down cam lobes. Just MHO

 
Last edited by a moderator:
yup you need more pump shot. when he car is hot the mix is lean.

 
My car would backfire through the carb if the timing was delayed too much.

Set the timing at 6 per factory spec and it would backfire, set to 10 no backfire.

mike

 
Last edited by a moderator:
Hello Coilwire,

My take on this is your distributor is not in the right stop with relationship to TDC. Pull your plugs out, insert TDC indicator with whistle on the end to locate the TDC while rotating the engine. The backfiring through the carb is the timing of the intake valves not closing all the way during the combustion cycle. Just a thought.

mustang7173

 
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