I have a 1989 GL10 Turbo that has a Legacy Turbo engine in it. Standard shift. During acceleration there is no sign of the hesitations but as soon as the Turbo light comes on the hesitations occur, usually 1 to 2 per second and really annoying on steep hill climbs. Has anyone else experienced this? We have checked the Knock sensor, Throttle Position Switch, Mass Air Intake, changed the plugs/wires/cap, improved the ground wiring, put in a relay for a better spark, checked for exhaust leak, checked the Air Filter. We ran the car without the Turbo and it still did it but not as much. We checked the fuel pressure. The two things left we are considering is the Car's Computer and the fact that there is a straight pipe in the car for exhaust and my mech was mentioning that the hesitations may be occuring with respect to a sensor and that there is really no resistance (that a muffler would provide) with my exhaust pipe. Another questions is: is a vacuum leak the same as an exhaust leak? I think we may be checked that but not sure as a vacuum leak is something that others have mentioned as a possible problem. Anyhoo, any thoughts would be very much appreciated.
Simon James