Bucking can't figure it out

[Britdog15]

Okay so far what's been replaced on the truck is plugs wires cap rotor battery fuel pump fuel filter ignition coil the truck has one car with a cherry bomb it has the stock carb and gas been cleaned new air filter and plugs have been changed because I pulled em to check and looked fouled. It's a 87 2.0 carb and me and my girls dad adjusted the black piece on the back of the carb because we had to pop the hood and push the carb down for the truck to start finally for it to where a couple pumps of the gas and it would start quick now a couple weeks later it started to begin a buck at 65 mph so put the clutch in and when I recede it it sounded like the truck died but I still had headlights and radio and I floors it with the clutch down again and it dropped rpms and then reved up. It stared to bog more I could only go about 45-50 the next day so I changed the fouled plugs and it let me go 65 but bucked at about 67 it was able to go faster then that when I first bought the truck I've been thinking I might need another carb or maybe the ignition count rol module? But not sure yet it will also get this symptom if I'm romping on it it around 35-45 mph as of now I can sometimes go 55 but no more and sometimes less until I hit a stop and gentle acclerate. Is it getting to much gas? Or not enough spark? Compression issue? I'm not sure and really want to get it fixed because its annoying going 50 sometimes less and eceryone passing you like your an old lady thanks guys

 

[Britdog15]

One cat*

 

[RonD]

Reads like not enough fuel.
Look at a spark plug and see what it tells you
Google: Spark plug condition

Could be float level in carb is wrong or sticking

Loosen gas cap, could be fuel tank is not venting properly and fuel can not be pulled out easily.

Cat could be clogging up, back pressure limits RPM, it can be tested with a vacuum meter or if bolts are not too rusty drop the cat out of the way and drive it, yes loud, and see if engine runs better.

 

[03huntin'rig]

My f150 bucked like a "bronco" and ended up being the distributer even after I had changed cap and rotor

 

[Mark_88]

I'd say not enough fuel...maybe fuel pump is going south or your filter if plugged...there should be one on the carb...

But as RonD said...could be the float level...my 2.0 would randomly just die and it turned out to be the float wasn't set right...but it was flooding and I thought it was spark related.