Ok my car is a 91 eclipse gst 5-speed with a new big 16. I gave it a full tune up. I have terrible idle surge that wont go away. So I took it to the local dsm shop and we swapped ecu's only to discover I had an automatic ecu that was bad. We also discovered I had A/T injectors. With the correct ecu my car stopped surging but we couldn't get the idle below 2000! So my question is would the 5-speed ecu which is programed for 450cc injectors cause the high idle. We are going to swap in correct injectors but I just cant understand the high idle. Any advice would be great. Thanks.