1978 Scout II with 392 Engine Problems

[wavesailr]

I've got a 1978 Scout II with a 392 V8 engine that's giving me problems only after it gets to operating temperature.

The engine backfires, stumbles, and has very little power after the engine gets to operating temperature. Before it's warmed up it runs perfectly and has lots of power.

I've replaced the mechanical fuel pump and that didn't help. I then bypassed the mechanical fuel pump and used an electric fuel pump. That didn't help either. The fuel pressure is about 3 PSI when the engine is running no matter if the engine is cold or hot at full throttle, or idle.

The timing is good at 3 degrees btoc using the #8.

The carb (Edelbrock Performer 600 CFM, electric choke) was replaced before I owned the Scout, but it looks fine.

The distributor and coil were replaced.

Please help!!

[TexasScout]

I am having same problem with my 78 345, I think mine is a carb issue. I will let you know when I have rebuilt the carb. At idling mine is fine once I romp on it backfires and seems like it is flooded out.

[texas sub]

my sons both had a couple of scouts. double check the corect timing, and check the timing chain/ they strech . when the motors cold so everything is tight. when things warm up they get loose and bounce. other thing is distibutor might be wore out
mike

[garscout]

Do you have the electronic ingition box checked?

[GreenMountainScout]

I seem to have the same problem with My 78 Scout. Engine idles and runs perfect until I've driven it for about 10 or so minutes.

My problem seems to be an O Ring that is located where the Shifting Arm enters the Transmission. There is a slight leak that, when seeps too much fluid, begins to make my Transmission slip. It almost seems as if the Carb is bad like TexasScout stated. I'll have to check my Carb too in order to double check everything.