1990 supra n/a idle problems
 

I have a 1990 supra with idle problem. It goes up and down but when driven and i come to a stop it drops really low and sometime cut our complete and i have to attempt to restart numerous times. There is no resistor pack installed could this be part of the problem??

Start with checking for error codes:
http://www.cygnusx1.net/Supra/TechTi...ror_codes.aspx

As it may not have been cleared in some time there may exist error codes which are for conditions which are no longer present; So, check it, write them all down, reset the ECU by pulling the EFI fuse (in the engine bay fuse box by the battery) for a few seconds.... Then drive it for a little while and recheck the codes and write them down. Post both sets back here.

I'd also check the TPS alignment. It has a switch inside which is used by the ECU to determine when the throttle plate is closed.

http://www.cygnusx1.net/Supra/Librar...spx?S=FI&P=101

I Ran the diagnostic and got a code 14. so i replaced coil and igniter and the code still showed up

Did you reset the ECU after replacing those parts? Is the wire harness in good shape? Has the ECU been exposed to any disagreeable conditions (such as heavy humidity from a blown heater core)?

Other than the code 14 have you checked for intake leaks after the AFM; clogged air filter; vacuum leaks; mechanical timing issues and proper spark advance?


I just noticed you're mention of the resistor pack... if you mean the injector resistor pack, 89+ N/As run high impedance injectors and as such do not use this. If you're referring to the fuel pump resistor and relay then yes, it is possible that you are running excessively rich.

i cleared codes but the resistor pack on the driver side near the shock tower is missing. when the car cuts off i smell gas during the restart there is no known intake leaks

the problems only happen after has been driven for a while or becomes normal operating temp

The missing resistor pack isn't your issue. If you had low impedance resistors and no resistor pack the injectors' coils would burn up... but 89+ N/As all have high impedance (denoted by the green tops (which, sadly, sometimes do fade to a yellowish color)).

So this issue is only happening when the car is going into idle? I'd continue working on the code 14 (wiring and ECU remain suspect if the igniter and coil are good) and also check the Coolant Temp Sensor, ISCV and TPS when the engine is hot. Try checking the diagnostic codes when the engine is hot as the code 51 is not a stored code.... it clears once the error condition is no longer present.