Anyone got any ideas on this problem?...

On my 1993 Jap WRX the engine losses performance after about 30mins of driving. After initial start up about (10-15mins) theres loads of power and the car is very resposive, but once the car has been driven for any length of time I notice a severe drop in power out put. Like its holding back.

My only theory is that the engine is heating up, and due to me using 98ron fuel with no octane booster, the ECU was retarding the timing or reducing boost due to sensing knock. I turned the heaters on full blast for 10 mins and the power returned on occassions, but still not 100%.

My mate has the same car and uses the same fuel etc, but says it doesn't happen to him.

Any ideas on this one? Thanks...

 

ecu would retain the retarded ignition if it detected knock and retarded the ignition.

standard that putting the heater on altered the power output.. possible the ecu temp sensor is faulty and it is thinking the engine is cold??
Fans on when engine cold is the usual sign for this.

Would be worth checking for error codes recorded in the ecu

http://www.saxonfields.freeserve.co....iag%20Page.htm

 

Thanks for that I'll give it a go :-)

Nathan