Post #8
I opened up the ecu and worked out that pin 22 on the connector leads to a transistor.
As far as i'm aware a transistor is kind of a bit like a relay in terms of it only requires a small current to then allow a higher current flow through, i.e. allow the circuit to complete for the injectors. I tested the resistance on the transistor and it had a low resistance between pin 22 and pins 12 & 13 (ECU earths).
This basically meant that the injectors were constantly open before hand, even with the ecu disconnected from the loom.
To check i traced pin 21 to the transistor to the left of the one used for main injector control and that wouldnt allow current through at all (This transistor is used for a second set of injectors if they are being used).
From doing the above tests i simply assumed that the transistor used for 'Injectors 1' was dodgy so i got the model number, searched online and bought an identical one, when it arrived i removed the old transistor and soldered in the replacement. I tested the resistance between pins 22 and 12/13 and there was complete resistance according to my multimeter.
I then put the ecu back together, stuck it in the car and tried the diagnostic test again, this time there seems to be nothing from the injectors (previously there was nothing happening with the injectors, but they got very hot after a short period of time as there was constant current running though them).
The ignition coil is firing when i do the diagnostic test so that side of the ecu appears to be fine.
Pins 12 & 13 (ECU earth pins) are grounded fine, and the switched live to one side of the injectors on the loom is showing 12V when i have the ignition on and the multimeter pushed against that pin and the other lead against anything that is grounded such as the block.
Hopefully the above makes sense.
All the sensors appear to be showing correct readings, i've had the dials up in dta win and blown into the map sensor which detects a rise in pressure, the tps sensor registers movement and i've set the closed and fully open positions for it.
I've just had a thought, i might try connecting the injectors to pin 21 and running the diagnostics test again, if the injectors then activate i'll know it's an issue inside the ecu rather than my wiring.
Just for reference i've tried two sets of injectors now, the standard iw204's which are known to be working, and my bosch 440cc ones that i'm going to be using once it's up and running.
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Goldie the track car.