This is topic 85 mustang gt in forum Tech Talk at Northern California Ford Owners  .


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Posted by 93 5.0 (Member # 12418) on :
 
My buddy has a all stock 85 mustang gt 5 speed and he tried to smog it but it keeps burping during the test like a miss only at 2500 rpm he's replace the cap and rotor wires plugs and new cats anyone have any idea what it mite be before he goes and buys a new carburetor timing at 10 and plus are gap to 44
 

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Posted by LXjames (Member # 10791) on :
 
Plug gap seems a bit tight try .052. Some manuals have suggested .044 but it's "not correct" per say
 

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Posted by 93 5.0 (Member # 12418) on :
 
Would that make it burp like a miss

 

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Posted by LXjames (Member # 10791) on :
 
I had 1 single plug that was under gapped on my hci notch and it caused a miss/thump in the exhaust while cruising on the freeway. Gap the plugs a bit higher and see how it goes
 

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Posted by Martinna (Member # 12493) on :
 
Can you post the smog test sheet? The hydrocarbons will read high if the burp is a misfire. Does the timing advance okay? You always should run as little timing as you can get away with for smog. 7 degrees on foxes. Less timing reduces your hydrocarbons and NOx readings.
 

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Posted by 93 5.0 (Member # 12418) on :
 
I'm going to go over there night after work and check every out and look at the paper work
 

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Posted by LXjames (Member # 10791) on :
 

quote:

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Originally posted by Martinna:
Can you post the smog test sheet? The hydrocarbons will read high if the burp is a misfire. Does the timing advance okay? You always should run as little timing as you can get away with for smog. 7 degrees on foxes. Less timing reduces your hydrocarbons and NOx readings.

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