Turn right, skips and jumps, turn left, back to normal, what the hell?

If turning left and right alters the power of the engine, I wonder if you've got a worn wheel bearing which is being made worse when you turn right and better when you turn left.

Is there any grating noise when you turn? What is the fuel economy like - has it got worse, as would be the case if there were frictional losses in the bearing?

1987 Japanese truck.... that'll most likely be carbureted rather than fuel injected. And they tended to use Mikuni carbs, which are notoriously ill-tempered as they age. Power loss at speed coupled with getting worse when turning one direction and better in the other sounds like a fuel delivery problem- stuck float valve, plugged fuel filter, etc.

Check the simple stuff first.

Worn or broken motor mounts classically make problems like this even worse.

Could have some water in the gas tank. My ranger acted quite weird after the top of the sender unit got some rust holes in it.

For me it was moderate bumps. Acted just like the ignition was cutting off.

It didn't have a strong gas smell, either,

Dave

Okay, got some carb cleaner, cleaned it out, replaced plugs, wires, distrib cap, and air filter. Oil/Oil Filter and clutch recently replaced. It seems to do it LESS, but it still does it. Might be carb, might be fuel filter, and I dunno where the float valve would be, how do I go about checking the carb further and the float valve, I'll get the fuel filter changed soon.

The float valve is inside the carb and maintains a constant level of fuel in the small reservoir in the carb that the metering jets draw fuel from. If you buy a carburetor rebuild kit, it will be included (new needle/seat for the valve, and sometimes a new float also). But you should know what you're doing before you tear into a carburetor, particularly one as cantankerous as a last-year-before-fuel-injection Japanese carb. Do the fuel filter first...

Wayyyy back in high school my mechanics teacher told us that

90% of engine problems were electrical. I fussed with carburetors and other fuel stuff for years until I began to realize that he was right. Ignition has always been a weak point (that's why aircraft have two magnetos but only one carb) and I now, at age 55, go after the ignition first. You might have a bad connection somewhere, and I'd start at the distrubutor (or coils, if no distrubutor) and work back. The engine torquing in its mounts, or leaning a little in a turn, is possibly pulling on some corroded or loose connection, intermittently cutting off the spark. 90% likely, remember.

Dan

F***ING THANK THE LORD. It was the fuel filter. I changed it, and god damn is there a difference. A-fscking-mazing what a $10 part can do to change how your vehicle runs. THANK YOU.

SIDE NOTE: WOOHOO I CAN ACTUALLY PASS PEOPLE NOW. I went all the way to work 70mph without a damn skip pop or fizzle.