Lack of power/poor mileage + surgeing

So I just got an 88 B2200 it seems to run well except it's totally gutless and gets only 20MPG at best. Everyone else seems to get like 25mpg. So if I hold the throttle at a steady like half throttle, I can feel the motor surging. Like it'll make a lil more, then a lil less power. Not steady. Any ideas what this could be? Sometimes I'll accellrate and it feels like it has way more power than other times. I was thinking maybe 02 sensor? or dirty carb??

do a tune up (plugs, wires, cap ,rotor, spray carb cleaner in the carb while it is running (have someone hold the accelerator down to keep from killing the engine, though) and change the air filter. less than 80.00 in parts and about 30-45 minutes worth of work and it will be good to go!

jeremy

also could be a clogged cat

i JUST RECENTLY DID THE TUNE UP. gIVEN IT'S BEEN OFF THE ROAD FOR A COUPLE YEARS SINCE THEN BUT ALL THE PARTS ARE STILL NEW. i DO WANNA PULL THE CAT THO. i RAN A LIL AVGAS THROUGH IT AND THAT CLOGS EM BAD

new gas? or the same gas that was in it?

Have you replaced the fuel filter? If it sat a while you may have rust in the tank.

post deleted

yet check the fuel filter.

but i was having similar probs and come to find out ma crank key was bent throwin the timing off a tooth.

gas mileage sucked and i had a major power lost!

i'm having a similar issue with an 89 b2200.. can't say much about the gas mileage since i've only owned the truck a few weeks, but i'm getting surging a lot... spoke with midnightmike and he figures carb rebuild would help/fix the problem, but i also couldn't drive the truck to see him so he didn't see /hear/feel it to know that.

at first, around 60-80km/h it would surge and lose power and lunge if i held it in place or tried to step on the gas harder, then it was happening at 50-60km/h, and now it's even happened around 20-40km/h. it seems more apparent the harder i push on the gas, so what mike explained was the colder (more condensed) air is messing up the a/f ratio and it affecting it. right after it happening, i can come off a red light, easing on the pedal and get above 60km/h without it happening, so it's not consistent.

i've recently sprayed *some* carb cleaner in (likely going to do it more one weekend shortly), and have done plugs/wires this past weekend.

note also i'm in london, ontario, and the weather has been getting colder and colder in the past few weeks as i notice this getting worse.

in response to mazdatweaker's post, i'm sure i have at least 3 different multimeter's, however i'm only home on weekends right now until after dec 19th, so anything suggested that i can test with that will only occur on weekends, and i don't currently have access to the unit's to know what is supported with them (though i'm sure i have at least 1 that's a digital multifunction and will have what i need).

Sounds good, I have one at work but i'll have to see if it has dwell. What is dwell might I ask?