hello people-would really appreciate some help on this one!! i have an `87 s2 that holds back and surges under med-hard accelaration.mainly when the engine is warmed up.here is a list of what i have changed/eliminated:fuel pump,fuel filter,injector seals,valve stem seals,plugs,leads,cap,rotor,have had ignition system checked by a garage,advance/retard pipe from ecu-manifold.also the car never seems to come up to temp according to the `norm` on the gauge.the needle is always below this section-even after extended or hard driving.(the air coming from the vents can be v hot!!!) any ideas and questions welcome.

cheers guys