This has been bugging me for some time. '93 P/U 4X4, 291k. It runs fine and the engine is real quite at idle, but for this ticking noise. Sounds like a relay opening and closing twice a second or so. Maybe faster. It goes faster with the engine RPM. I don't think this is the EFI as I hear only one loud click and not 6. I can't seem to trace it down, but it sounds like someplace on top of the engine.
Anyone know what this is? Thanks
-Eddie