My 67 289 mustang is cutting out at around 70 mph and wont go any faster . At 0-60 it runs like a bat out of hell and has plenty of power . I have checked the fuel filter,it has a edelbrock carb and i pulled out the needle jets and blew them out ,the fuel pump is sending fuel and it seems to be firing ok at idle dont now at 70 mph.I put some fuel additive in it and seemed to help a little but still it cuts out ? Help me please !!!!!

 

More info needed, like is ita 4 or 2 barrel, type of ingnition system etc.

 

OK . It has a 4 bbl and accel pointless ignition and high volt coil.

 

What gears do you have in your rearend?

 

my thought exactly

 

it may have a rev limiter built into the ignition system and if your running really low gears it may be kicking in the limiter at say 5000 rpm

just a thought.

-Gun

 

What exactly do you mean by cutting out? Ifyou have really low gears that could be the problem but you would be rapping the engine to it's max redline. If that is the case then you would need to change gearing, if we are talking about an engine issue more description of "cutting out" may help to point you in directions to look at.

 

Here's my guess...

It might be an ignition problem with the timing advance. What RPM does it cut out at? If you drive it slower, but in a lower gear at the same RPM, does it cut out?

 

it ran fine about two weeks ago matter of fact fast enough to out run a turbo charged solstice(pontiac) aprox 130-140 mph so 70 mph is about half what it will do ,it does not have a rev limiter,. so it has to be either fuel or fire . cutting out = missing , modulating, not a steady run. like i said it will run like a bat out of hell to about 70 mph and then starts cutting out not so much missing because that indicates a ignition problem right off the bat. i think i have a water in the fuel tank and maybe at high speed it is not getting the fuel to the carb.

 

Check your plugs for a fowled one?