any ideas may be helpful

[1995greenstang]

okay just did the gt40phead swap on my 95
runs fine but after driving for about 30 minutes it starts puttering kinda like soemone took off 3 of the plug wires but if i mash t to the floor it jumps and comes alive and goes. any ideas?

 

[earleys94gt]

Did you gap the plugs correctly, or get the right plugs?

From my expierences, it has always been something "stupid" like that.

Check all the obvious, over looked stuff first, and go from there.

 

[reddy351]

Maybe loose fuel injector plugs or a pinched fuel line? Could be a lose vacuum line, too. (Higher vacuum pulls the line back up onto the bung enough to stop the leak.)