High RPM backfire/popping

[Brownie Mobile]

So i dont do a whole lot of highway driving in my B2 but yesterday i took her out on the highway going 55 up and down hills and when it shifts and the rpms got really high she started missing( or something) anyways i lost power and there was some loud pops im assuming that my spark plugs are just old and in need of replacing and just cant handle the high rpms and doesnt completely fire the gas in the cylinder and it goes out the exhaust and creates the backfires lemme know what you think at those high rpms and high highway speeds it created a lot of shaking and was actually really sketchy and interesting to see how much 1 cylinder can affect the power.

 

[hopster]

what kind of rpms are we talking about. high enough for valve float?

 

[RonD]

I would replace the fuel filter, $10

Restricted power and missing at higher speeds and higher RPM are the first signs of limited fuel flow.
Could even be the screen filter in the tank on an '84

 

[Brownie Mobile]

what kind of rpms are we talking about. high enough for valve float?

umm im not sure really dont have a tach but id say probaly 5-6 grand you know going up a hill at 55 in a 3 speed automatic and it shifts down to second lol.

 

[Brownie Mobile]

I would replace the fuel filter, $10

Restricted power and missing at higher speeds and higher RPM are the first signs of limited fuel flow.
Could even be the screen filter in the tank on an '84

So how would i get to this screen filter? i just replaced the fuel filter and its still nice and clean looking.

 

[RonD]

Have to drop the tank and pull out the fuel pump.

Just as a long shot, loosen the fuel tank cap so air can get in.
Maybe venting system is clogged and over time at higher speeds your tank is building up negative pressure so fuel pump can't pull enough out against the vacuum in the tank.

 

[RustedRanger]

Usually plugs are not gonna just "go bad" all at once unless something else fails.

 

[Brownie Mobile]

Have to drop the tank and pull out the fuel pump.

Just as a long shot, loosen the fuel tank cap so air can get in.
Maybe venting system is clogged and over time at higher speeds your tank is building up negative pressure so fuel pump can't pull enough out against the vacuum in the tank.

Definitely gonna give that a shot, i just hope my 8 dollar locking gas cap doesnt unscrew itself the rest of the way and i end up with a paper towel gas cap like my truck had when i got it.

Usually plugs are not gonna just "go bad" all at once unless something else fails.

But wouldn't it make sense if the plugs werent sparking well that when adding more gas they could get an incomplete burn where as it wont do it for normal generaly low gas needs city driving?