damn stupid question time (and I'll preface this by saying I know NOTHING about egines)... I have a running problem with my car - seems to not like starting on all 8 (popping and back firing) but once even slightly warm it seems to idle quite well (if a little lumpy - due to cam I believe) seems to rev well when parked but as soon as it is asked to perform under load (eg smoking a jap car) it bckfires pops and farts all over the place (a 383... edelbrock heads... mild road cam... holley 750... headers) and it only occured after my plugs were changed... it has been suggested that the gap on the plugs may be a little big... I believe they were set @ 60 thou (compared to a stck 305 being apparently 35 thou)... and seeing as this is all that has been changed apart from one lead which has managed to burn itself on the headers ( )... any other ideas about what to check? Just thought I'd tapall your brains out there before I get to having a go on monday with a mate of mine and spend hour doing stuff we needn't or if there are any more ares which could cause 'issues'

 

first off start with the obvious. if a plug wire is damaged then replace it. next if the problem started right when u changed the plugs check and make sure the plug wires are installed correctly. make sure #1 goes to #1 plug. you could have a crossed wire. (i've done that before) also recheck that gap. seems to be a little on the large side. check the gap on the old plugs u removed and compare. are they the same brand? type? part number? also check and see if your distributor moves without to much force. it could be the distributor moved a few degrees.