popping thru exhaust

[cdeezy2003]

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i am just completing a new build, its a 427 sbc with a ysi on E85 thru a QFT blow thru carb. for ignition i have a digital 6 and a boost timing master (P/N 8762) with a pro billet distributer set at 34 degrees locked out. on my wide band at idle im around .85 lambda and it wont quit popping out the exhaust unless i advance the timing W A Y high, like to 60-70 degrees. i called msd and they told me to switch some wires which i did and from the result they told me i nedded a new mag pickup in the distributer, no problem thru one in; no fix, called msd back and they said my timing light was junk( it was new last year and hasnt failed yet) and didnt know nothing else. called QFT and they said all my settings on the carb were fine. im getting ready to panic, i gotta get this ironed out if i can so i can take it to allout in indy next week. anybody have any thoughts?

thank you in advance.

 

[purple barney]

is your timming light a dial back? i had an issue with my new timing light being a dial back and msd ignition system. it has something to do with the multispark msd puts out. my light would read 30 then 10 then 40 ......its just a thought if a friend has a good old standard inducitve timing light give it a try. i

 

[cdeezy2003]

nope, its a standard light. thats what msd hit me with and after i told them that it was a non dial back he was like "oh....uhh....well its not possible for your car to run like that." but i know it is cause im standing here looking at it run like that.

 

[LS6 Tommy]

Something seems out of wack. If more advance helps, especially 60-70*, your distribby may be off a tooth or something. Popping out the exhaust is usually an indicator of not enough advance or too rich of a mixture.

Tommy

 

[holtjohn]

or a flat lobe on the camshaft or a bent valve.........

 

[Anonymous]

or a flat lobe on the camshaft or a bent valve.........

Or a broken spring.

 

[cdeezy2003]

turned out that my timing light is junk, took the car to the local speed shop and 75 bucks later i got my education that my light doesnt work right anymore. just glad it wasnt anything serious. thanks for the replies!

 

[racecar77]

I'm confused. If it's a standard inductive timing light and not a dial back, it either lights or it doesn't. What could be wrong with your timing light? Glad you got it straightened out though. Lee