so my buddy has a 94 delsol d15 automatic....lol
the only problem with the car is that once the car hits 1500 rpm(driving or sitting idle) the motor starts surging and dropping rpm. not a ton but easily from 1600-1400 once your past that point it runs fine or is no longer noticed at least.
my first thoughtwas dizzy. i took one of a parts car and gave it to him and same problem.
next thought was iacv or tps. so i gave him another throttle body and same issue.
he was told from someone else that maybe a speed sensor on tranny but i have no experience with automatics..

any help or suggestions would be greatly appreciated
adam jeffery

 

How old are the plugs, plug wires, and fuel filter?

Any CEL codes?

 

not sure on plugs or fuel filter but has brand new cap rotor and wires.
also if it were plugs wouldnt it effect all rpms? it literally doesnt start till 1500 and ends once you throttle out of it....thast what has me stumped.
adam jeffery

 

For the type of problem you are having, it's always wise to start with the basics, beginning with the ignition system, which is the most common type of failure.

 

its my buddies car so im not sure on all the details. but the only ignition thing that im not sure of is plugs everything else in new for sure.
adam jeffery
ill ask him abut the plugs but he is pretty thorough with keeping up on maintanence of his vehicles
adam