as title will it work or not?? has anyone tried it?

 

Why not just use the whole 90 spec ECU?

 

i think there's a problem with my knock sensor circuit, so i was gonna get a std s1 ecu cheap and put my chip in.

 

the knock sensor is only 2 wires, so should be an easy fault to trace.

Best way is to plug a sensor in and cable tie the sensor out of the way behind the heater box

 

yeah there's only two wires, but the actual circuit in the ecu is alot more complicated. plus i haven't got a spare sensor to try and the only one i can find for sale is about 50 quid from burton power. quite alot considering you can get an ecu for about 20 quid.

 

Take your knock sensor out then and give it a try, theres not a hole in the manifold.

 

tried that today. still the same. i think either the sensor or the ecu is totally fooked.

 

hmmmmmmmmm.......can you borrow a sensor off anyone?

Whats the problem?

 

don't think so. i tried bypassing it with a 550k resistor but it ran the same so i think it's the ecu. basically the car holds back when coming on boost. runs ok with the timing advanced. obviously i don't want to run like this in case i melt a piston. there's a chipped s1 ecu on ebay so i might try that. but if my chip will go in then i could get a std one for alot less

 

But the knock sensor is a piezo, not a resistor

 

yeah but it also has an internal resistance. you can fool the ecu into thinking the sensor is connected by substituting with the correct resistance. the piezo xtal is only active when det frequency is present so the ecu doesn't know any difference. well that's the theory anyway.

 

Is that a proven method though?

 

hard to say. most knock sensors are piezo resistive and just alter their resistance when det is detected, others are piezo electric and apply a voltage when det is detected. either way when there is no det present is just acts like a resistor. i know it works on other ecu's so i don't see why not.
without seeing the schematics for the rs ecu i can't say for sure. either way if i put a series one ecu in it will cure the problem whether it is the knock sensor or the ecu anyway. maybe i could just use it as a stop gap and fit a megajolt system. seems like a cheap option for 3d mappable ignition.