I have a friend who recently did a SR20DET (S13 red top) swap into his '93 240SX. He has everything that's supposed to go into the swap except for the ECU. He's still running the KA24DE ECU. The motor runs fine in normal traffic but whenever pushes it (WOT) the exhaust temperature gets dangerously high. Could this be because of the ECU? Anybody have any ideas of what could this be?

I forgot to mention that since he made the swap he has upgraded his fuel pump to a Walbro and also has a Vortech 10:1 FMU. Thanks for the help.

 

c'mon people, a little help here please

 

Of Course it is.
The ECU stock in a 93 with Fed markings will run the Injectors Lean at above 5K. That is one of the programmed limits.
And there will Also STILL be a .5sec delay and retard in timing at normal accell.
If it is a CARB ECU(cali and the likes), it will be worse for lean running and etc. over any other ECU.
A Fuel Mgmnt Unit would help fool the ECU and allow a richer setting up at the Higher RPM levels, yet by the time money is spent on the FMU and setup, the Overall benefit would not Match Getting an ECU from JWT. It will BREATH real Life into an otherwise 14 sec SR-T.
Just a little info