I have an 86 Rx-7 n/a. Did a turbo II swap with a 1988 jspec engine that has 50,000 miles on it. Car runs great. Changed injectors, cleaned all grounds, new fuel pump, new filters, tested tps, new N318 boost sensor, new N318 air flow meter, new spark plugs and wires and new blow off valve. The car idles great when its cold, but when it warms up it wont idle. Before the car quit idling it started to idle really rough for a month, then no idle at all. Does anybody have any ideas to fix it? Really apreciate the help.

 

check for vacuum leaks.

 

I checked all the vacuum lines and they are all good I changed a few of them going to the monifold, but it didnt make any difference. Could the bypass air control valve affect the idle? Or the tps... the voltage it was putting out was around 2 volts. The meter is used was not very accurate however.

 

TPS will affect it some if it is that far out, none of the solenoids will cause it to run rough, it is all metered air.

check for leaks with a can of carb cleaner.

 

Thanks ill try it out tomorrow. when it warms up now it wont idle at all. Ive been comming to a stop one foot halfway on brake and throttle, I like to show my friends my car and try my hardest to make it idle when stopping lol. The only thing that can cause that is a vacuum leak? Does the variable resistor do anything with the idle? I dont think the bypass air control valve is working properly not sure if that will make it not idle.

 

You can also check the Water Thermosensor reading at pin 2I of the ECU. Should read 2 to 3 volts w/key to on and engine cold and a fully warmed engine will read just under .5 volts.

 

Where is that water thermosensor located on the engine? I think that sensor might be no good.

 

It's behind and towards the top of the water pump just under the alternator. It's easiest to check at the ECU as the service manual test requires removing the sensor.

 

Thanks satch the sensor was bad, idles alot better now still alittle rought. maybe ill try the variable resistor and see what it does.