I have a 1987 Chevy C10 pick-up. It has a 350cid with throttle body. When first started and still cold, it has enough power to light up the tires if I wished to. Atfter it gets warmed up, sitting at an idle, it will cycle up and down in rpms, almost stalling on the low side, going down the road, it feels like I have a four cyl under the hood, and after giving it generous throttle to compensate for lack of power, then backing off, the check engine light comes on. I can shut the truck off, wait 30 seconds, start it up and it will run better briefly until the whole event starts over again. I checked the diagnostics, and got a code 43. The code book I had available to me listed a few reasons. One being TPS adjustment, another being a knock sensor, and yet another blaming the ESC. The erratic idle would lead me to believe the TPS is the culprit, but I thought bad was bad, not an intermittent problem. The truck has had in the last year and 1000 miles,,,new radiator, cyl heads, plugs wires filters hoses alternator starter battery brakes and a few other small odds and ends. My brother in law got tired of putting new stuff on it and gave up. He told me to just take the thing...lol. It aint pretty, but he put so much money into it, and since I needed a wood hauler... Any thoughts or help would be greatly appreciated..thanx

Thanks for prior assistance. The hood problem proved to be a broken mounting on cable housing. Ireplaced the battery, and the car started easily, but immediately began making a racket and it is burning oil -- which it has not done before. Does this always mean worn ring or burned valve, or could it have blown a gasket? How do I check? Is this a "do it yourself" or "do it for me" problem? How long can the car be safely run in this condition? (On restart, the car did not smoke, but it is clicking loudly.) Thanks for patiently answering my questions without insulting. :confused: