Back Firing

Please help any ideals welcomed. When I let off the throttle it rumbles down but it is loud enough I would consider it a back firing down. Stock bottom end, E-303 cam, 185 afr heads, 75 mm throttle body,24 lb fuel injectors, timing on 11 degree, egr delete, fuel pressure at 38 lbs,1.7 rockers.
 
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I'll be first. Did you run the codes? What kind of ignition are you running? And more explanation on sound/activity you are experiencing.
I'll be first. Did you run the codes? What kind of ignition are you running? And more explanation on sound/activity you are experiencing.
Did not dump codes.
I'll be first. Did you run the codes? What kind of ignition are you running? And more explanation on sound/activity you are experiencing.
Did not run codes. I have a MSD 6al ignition box, factory dist, only sounds like a back fire when coasting off the throttle.
 
Highly recommend dumping codes first. Find out if it's any computer,sensor,etc problems. Do that before throwing parts at it. Also fwiw a few people have been claiming MSD have been having problems with their ign boxes.
 
Highly recommend dumping codes first. Find out if it's any computer,sensor,etc problems. Do that before throwing parts at it. Also fwiw a few people have been claiming MSD have been having problems with their ign boxes.
my experience with the msd failures is it either works or it doesnt, fwiw
 
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Backfiring usually points to a lean condition.

With your mods, I ask if you ever had a tune done? Are you using a mAF calibrated for the 24s?

The EGR being deleted may also play a role.

First thing to do is run the codes and address what comes up. There is no fuctional check engine light in an 88, so it doesn't hurt to buy the $20. Equus 3145 code reader and get in the habit of running codes
 
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Always run high octane never mix becausethe guy before me shaved the block now I have 10.4 to 1 compression
Kinda curious here. You say you've got stock bottom end,SHAVED block, e cam,185 Afrs,and 1.7 rr. My ?? How do you have ptv clearance? Are the pistons notched? I've always heard there is clearance issues with 2.02 valves in the Afr 185. And you decked the block enough for over 1 pt in compression?