86 T/A 305 carberated, AT, just finished rebuild car will crank and run with timing set at about 10 to 12 TDC but will not idle at 0TDC (factory setting). Car has ALL origanal equiptment and I'm sure my A.I.R. system and other sensors are in place and there is no noticable cause, I replace the whole distributor and there is no codes in diagnostics, and the car has no power at all when under load and will not even reach 15 m.ph.. I rotated the distributor 180* and the car would just backfire out the carb! I am sure that cranktocam timing is correct...so somebody please help me!

 

Sounds like it could be a crank to cam timing issue. Is it a OE cam?


How does it run with the 10-12* advance?

It could be that the harmonic balancers mark is way off which is not at all unusual!

 

When I put in the new stock cam I set the timing as cam at 6:00 crank at 12:00 and put on a new double roller timing set. It runs like crap at all times unless I idle it high, I reset the idle screw from 500 to 750 just so it wouldn't die, and it only runs good if I advance the timing so far that I can't see the damper mark and then rev it to at least 1500 r.p.m. The damper is origonal and timed fine before rebuilt....new crank gear too....but I am still listening...is this Ignition Spark Control Module on the firewall or in the distributer in a 1986 305 carburated engine code H?

 

Do a compression check and post back.

 

check your plug wires. first thing first you've got backfiring doesn't want to idle and had it all apart, put a distributor in it... check to see you have the firing order correctly again. never hurts to look a second time. check specifically 4/8, and 5/7. mix three up one side. and it'll act like that.