fuel injectors. any efi resistor for gen 2 3sge? sw20 mr2 had fuel cut off?

[bajachris88]

Hi. Sorry for the length but please hear me out, i'm stumped.

I have just put a gen 2 3sge into my st162 celica.

Its a jdm st162 with a jdm gen 2 3sge with a jdm 1990 sw20 mr2 ecu (3sge manual trans). I got spark but believe i have no fuel from the injectors. If i spray fuel into the intake manifold it fires up momentarily, fuel pump is working, fuel gushes from the fuel rail when i open it up so there is plenty of supply.

I was looking at the wiring diagrams, and thought it could be the absense of a 'efi resistor' (aka solenoid resistor) that could be causing issues. I didn't recall seeing one in my engine bay, so i looked at my old original loom AND THERE WAS NO PLUG FOR ANY EFI RESISTOR. Nor was there any efi resistor plug in the new loom from the st182 celica that the gen 2 3sge engine came off. This proved there was never originally a efi resistor used.

The Black & Orange wire supplying power to the injectors branches off and also powers the ignitor and coil etc with no efi resistor in line between the black and orange source and injectors. so if the engine was firing up initially, that means there was current going to the injectors as it was also firing up the ignitor and coil to spark etc in the circuit... which suggests that the injectors must of not been getting earthed by the ecu if they weren't functioning.

SO NEXT QUESTION. does the sw20 mr2 have a fuel cut off for security or does it have a 'clutch in' start routine or neutral start or something? (its a manual ecu though). Does the sw20 mr2 (1990) have a efi reistor? Is it unusual for my 3sge st162 (87' jdm) to not have one? it was a good runner prior to its death.

Any help appreciated and any thoughts as well. For the moment i'm going to go outside and take my multimeter and fish around...

[jonathan yee]

all the NA 3sge's have high imp injectors so no resistors for the inj's are used.

as said in your other thread there appears to be a difference between the 89-91/92-93 ecu's so if you have a pre 91 ecu but a post dec 91 wiring loom you'll possibly need to repin/move some of the wires acorss for it too work.

[bajachris88]

Hi Jonathan, thanks mate.

Yea i opened up the ecu and it had the pinout printed on the pcb circuit board. I compared it and it was fine.

Was just a few pins like Cco and ps and some other power steering one... but the rest was all good. Thanks for clarifying about the efi resistors, thats excellent. i don't need to worry then.

just an update though. I got 12volts going to the ecu plug. so there is current going through.

BUT! could a bad e01 or e02 earth from the ecu cause issues? I thought the black and orange wire was a power supply... and the ecu earthed it when the injector was 'ready' to be squirted. But i had some other guy telling me that the black and orange lead was the earth and the ecu supplies the 12volt current??

regadrs,
Chris.

[jonathan yee]

no your right the black/red wire supplies the power and the ecu earths to fire the inj's