truck loses power and surges at hwy speed??

[chronos]

Have a problem were my truck loses power and surges at hwy speed

Have a 350 trans , this problem recently started happening when i hit about 80 KPH which is about 50 MPH
happened today at 60 KPH or about 40 MPH.

I'm into 3rd when it happens and it feels like the truck is going to die , then I coast for a while and it seems to go away.

Checked fluid and its good , any ideas?? Thanks

[eventhorizon66]

When is the last time you changed the fuel filter?  Do you have a kink in the fuel line?

[Armor]

same thing happened to me when i got to the bottom of a tank and sucked up all the crap, my fuel filter was almost black, you couldnt even blow through it, check it and change it to see if it fixes the problem.

[Irish_Alley]

x3 on fuel delivery problem

[chronos]

Thanks for the input. I changed the fuel filter , it looked good , but I popped the new one in.

Still having the same problem today

Fuel system looks good and this problem never happens just driving around town,
only when crusing hwy, maybe It's not going into 3rd gear after all. REALLY hope its not my tranny?? Weird

[Reinovator]

 you may have a week fuel pump, or a loose vacuum line.
 also check timing and distributor cap and rotor for carbon tracking unlikely but worth investigating.
last thing check your timing chain.
is this  a V8

[DnStClr]

 Since you said it's your truck I guess it's the 86. It sounds like the transmission isn't shifting into 3rd. You should be easily able to tell if the rpms are staying high at 80kph. Tranny will be screaming..Is the fluid ok?

[VileZambonie]

  Do you have a kink in the fuel line?