Engine problems -- slight backfire ...
 

I've got a mid-80's 350, Edelbrock Performer intake and HEI with 700r4.

Installed new Edelbrock 650cfm vacuum 2nd's and new spark plugs gapped @ .045's.

While idled @ ~ 700 RPM, no problems -- but once I put into gear, I get backfire sputers on the passenger side AND I have no
power out of engine --- used 2x the amount of gas today going to work !!!! :mad:

VERY frustrated. I've followed Edelbrock carb tuning tips
--- back out 2 full turns, turn in clockwise ( one side at a time ) till RPM drops and put back a 1/8 turn. BTW: timing's at 8 degrees.

What am I doing wrong --- what else do I need to check ?

Sounds like you might need to advance the timing a bit more. My 350s running at 13-14 degrees advance. I could b e wrong though.

HotRod

If the carb was only thing changed before the problem developed, I would look for a vacuum leak. Strongly suggest rechecking the plug wire location. Sounds like you may have crossed two.

vacuum advance
 

Well --- I removed the carb and blew air through the port vacuum inlet and installed a 1/2 riser.

Power has been restored to engine -- but still backfires on the passenger side, not at idle anymore, but during acceleration.

Does that mean I too rich or too lean ?

Thanks for all the guidance !

i think that means it is to rich but why is it only happening on one side

Check to make sure Your plug wires are in the right order and there is no crossfire.I would advance the timing a little.Mine with hei runs best at 12 btdc

make sure you check the firing order and timing. i had the same thing happen to me and it caught my carb on fire!

My guess is vaccum leak, check the manifold "T" fitting directly behind the carb, on the manifold. Sometimes if this is off it pulls additional air right into the right side causing backfires and sputters as you describe. You may also want to check the vaccum port on the rear of the carb itself to see if there needs anything connected or plugged off.