[DrStang]

After a bit of driving (30mins) my fastback starts to stall at idle (traffic lights etc. Until then it runs great. Any ideas why. (just an aside- The temp guage does not read too hot-BUT there is quite a bit of underhood heat--I have headers. )

 

[camachinist]

Vaporlock?

IIRC, the fuel line isn't too far from the header on the driver's side, yes?

It could be other things but that's the first one that comes to mind...

When it stalls, how hard is it to get started again?

Any warning before stalling? Or are you saying it doesn't stall but begins to run rough like it's going to? If so, does revving it up solve the problem? How does the car run otherwise, say on the freeway on a similar day...?

Get back to us...

 

[sharkmouth]

My 3 guesses...

too rich mixture, particularly idle

condensor going (if it has points)

vapor lock