I have a 1994 Amigo. The engine starts fine and runs great until it reaches operating temperature. Then the engine surges in perfect pulses of about 2 seconds each.Once the engine is running above idle it runsgreat.Can anyone tell me what this problem is?This vehicle has about 85000 miles on it and it is a stick shift. Thanks

 

try the idle air control valve

 

it is your intake manifold gasket i spent alot of money changing everything ,like o2 sensor ,map, mas,and alot more.good luck

 

Mine just started doing this a couple of weeks ago, isn't bad yet, but I'll replace the intake gasket, see what happens.

 

Thanks for all your information. The problem did turn out to be the idle air control valve. I could only find this valve at the Isuzu dealer.