Start up issue 1994 GMC Sierra 6.5 TD C2500
I will let the glow plugs heat up and let the light go off, but when I start it, it will idle slightly high for about 1 to 2 seconds(then check engine light comes on), idle low for a split second and then normal at which point the check engine light goes off. Can some one explain what's up here? Thank you.
1994 C2500 6.5 TD. No mods, completely stock.