Hey all,

Previously owned an '87 Mazda B2200 and recently bought an '88 Toyota Pickup. The guy who sold it to me had done extensive work on Yotas in the past (SAS, 2x4 to 4x4, etc) and had pulled off the bed and replaced it with a welded steel and oak plank bed of his own design. He also replaced the clutch, pressure plate, pilot bearing, throwout bearing, head gasket (rebored it), radiator, water pump; replaced the timing chain with a heavy duty timing chain and steel timing chain guides. All of that is probably irrelevant here, but I just wanted to give an overall impression of the truck.

My issue is this: I've noticed that the engine will rev up and down with a regular frequency when I'm stopped. It doesn't rev up when I warm the truck up; it only does it after I've been driving it for a few minutes. My guess is that it's related to the throttle plate, but that's as far as I know. Any and all help is appreciated. I'm a newbie when it comes to autos in general but I'd like to learn and fix things myself.

tl;dr: 88 Yota that revs up and down. What do?

L

 

Might want to check out the TPS. It can affect the idle speed