So im new to the toyota world ive been playing with Datsuns the past few year and have never had this issue before. Last night i picked up an 81 pickup runs and drives great, i drove around for a good hour after purchasing it and gave it a good beating. ran fine until i got down the street from my house the throttle started sticking, or so i thought. It only seems to do it when its up to temp. i though it was maybe a sticky throttle cable until i realized that the throttle only "sticks" until i bake and come to almost a complete stop then the rpms will drop down. when in neutral you can stomp on the pedal and the engine will rev and drop the rpms like normal, but as soon as you take off in gear and step on the clutch the rpms stay at about 4krpm until i come to a stop. Today I jacked up the rear end and put it in gear and it only happens when going past 10mph in 1st or 2nd gear im, thinking it could be vaccum or electrical related since its only happening when im rolling? Im in CA is it an issue with the ca compliant carbs? Its just a guess rite now like i said im new to toyotas so any info would be appreciated, thanks in advance. Earl

 

Bump.

 

So...you're driving along, push in the clutch and the rpms stay the same. They only drop down once you've come to almost a complete stop. Right? Is the braking what you think is dropping them, or would the same thing happen if you coasted to a stop? Is it the actual brakes, or the speed?

It does sound like a throttle or choke issue to me. Have you sprayed the crap out of the carb with cleaner? I would lean more towards something in the carb than the cable.

Have you checked for vacuum leaks yet?

There's a part of me thinking clutch, but that's kind of a long shot...doesn't sound quite right.

Was the truck warmed up when you tested it in the driveway? I mean could it maybe have just not happened, or does it happen every time you drive, but never when you jack up the back end and keep it stationary?

I mean even if it's vacuum or electrical, why would speed matter? Then engine doesn't care if the back wheels are on concrete moving the truck along, or spinning freely in the air, right? It's all the same to it, other than there being no "load". I don't really see that affecting vacuum or electrical so much.

Anyway, since you're saying it only does it when you're moving, I'm just making sure you were setting up an accurate way of testing that idea. If it only happens every now and then when you're driving, then just jacking it up and driving it "in place" once doesn't really tell you much.