1989 Isuzu Amigo • 4 cylinder 2WD Manual • 160,000 miles

I'm stumped. I bought this Amigo a month ago. 2 mechanic shops later, no one can seem to tell me why it gives trouble starting cold. Once you get it started, it runs really well. (Except for the fact that it revs up and down on its own at times, but not consistently) 4 mechanics are completely stumped as to the problem. They started out telling me it was a fuel problem no most think it's an electrical problem. We've changed fuel pump, regulator, filter and plugs. Check engine light is on also. Any ideas? I'm about ready to push it off a cliff.
January 7, 2011.

Don't push it off a cliff. What engine code are they getting from the computer (check engine light)? Also, 89 was a while ago. If I recall, it has a carb and not fuel injection. Have they checked the choke? You know, I just reread your post. Have they checked the idle air control valve? The idle issue points me in that direction.

The amigo is fuel injected not carb. I noticed something on it this afternoon. When you initially try to start it, it turns over and over but doesn't start. A few tries into it, I finally hear the fuel pump "kick in." After this, it starts right up. Someone suggested it might be a short in the ignition switch. Any other ideas?

Jan 7, 2011.
It could be the switch, a bad connection to the pump, or the relay.

Finally got codes today. 14 and 41. Bought the Engine Coolant Temp Sensor (code 14) only to discover there's no wrench head on the original one. Does anyone know if there's a special tool for getting the old one out?

Jan 11, 2011.
It has to have something. They make special sockets for sending units. Ask at the parts store.