When the engine is cold the truck runs rough at highway speeds, but while accelerating runs alright. When the truck warms up it starts running fine. Also, i dont know if problems are related, but when it gets hot it is hard to crank until it cools down. It also has stalled for no apparent reason. But next day it crank right up. I assume after it cooled off. We have replaced fuel pump. The pressure is fine on it. New fuel filter. It has new plugs and wires. Any help would be appreciated.
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1999 Chevrolet S10
Question: Why does my s10 run rough until it gets hot, and not crank good after it is hot?
Answer #1ianascarfan6 April 20, 2012, 00:04Enthusiast
as far as the starting goes when its warmed up- most likely is the battery has a dead cell or 2 in it, recently had the same issue with my 4.3 Jimmy. the running rough when cold- first thing id check is that ur plugs are in snug and your plug wires are all completely snapped on- if they r good- check for a cracked or broken vaccum line