Stumped. I've been working on a 92 GT with freshly built 306, GT40P heads, 70 mm tb, b303 cam, 24 lb injectors and mass air, explorer intake. Car ran good but smoked so we bought a good known short block, and had the heads redone. The problem is the timing. At mid rpms the timing is aroung 40 degrees then falls at a higher rpm to 20 degrees. Runs like crap at 10 degrees at idle with spout out. Runs decent at 24 degrees at idle but should not run at this high of timing.Any settings between that it backfires like crazy between shifts. I've replaced distr., coil, tps, harmonic balancer, timing chain and gears, and mass air,off of a goodrunning car.Tired of messing with it, its probally something simple. Any help would be appreciated.

 

Why do you have the spout out?

 

24 degrees at idle is about right, with the spout connected. i'd say you might have a PIP or ignition module problem.

 

Thats 24 degrees with the spout out. Replaced pointer and made sure the cam and crank were lined properly.

 

is the timing light on the correct spark plug wire?
first cylinder on the passenger side

 

Its my fifth year working on 5.0 mustangs and never ran into this before its probally something overlooked. just can't figure it out. I checked the codes and nothing that relates to this.

 

Yep.

 

distributer has to be installed incorrectly.
it wouldn't even start if your base timing was really 24.

 

Put in three distibutors, two harmonic balancers, two pointers, two timing chain sets. and used old cam which ran good at 10 drees on old engine. I work on these things all the time because we race them. but never ran into this before. Had to other long time mustang owners and engine builders look at it and they cant figure it out either.

 

something isn't adding up here. hmm.