Neighbor sold me his 86,000 mile '95 Nissan Hardbody 4x2 2.4L 5 speed, he'd fairly harshly overheated it when the upper radiator hose broke the nipple off of the radiator. I've since fixed the cooling system (basically flushed the water jacket on the block, replaced all rubber, replaced the radiator, the thermostat, the thermostat housing), changed the oil, checked the compression both cold and hot (avg 150psi cold, avg 160psi hot, high-low range across four cylinders less than 10psi under each condition), changed the plugs and wires, changed air filter, replaced the blow-by hose between the valve cover and the air cleaner. It ran really rough at first but seems to be getting better, but the idle is still rough. The tachometer also doesn't read-out correctly, tending to hover just off-zero at idle, and to reach maybe 1500 while driving. Occasionally it wants to show the right readout, it'll jump up, but then come back down. I'm not sure if the two symptoms are related. I've already checked the throttle pressure sending unit, got about 0.57V at idle, about 4.09V at wide-open, with hot-to-ground of 5.13V. Haven't checked anything else under the hood yet. I do need to replace some of the plastic between the air cleaner and the fresh-air intake, but that stuff shouldn't be causing any particular problems. When I first got it running I got a small smattering of codes, a Code 43 (TPS), a Code 41 (something about an air temperature sending unit), and there *might* have been a Code 32 (EGR sensor). I tested TPS before I thought to reset in case any/all of these codes were from error conditions caused by the overheat. After resetting and driving probably 30 miles I haven't gotten a CEL, but the rough idle seems to persist, along with the tach problem. Any suggestions would be appreciated.