fuel injectors. any efi resistor? 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...

Chriso.

[bajachris88]

Update: I got 12 volts from each injector plug going to the ecu. thats been confirmed at the ecu plug.

Could a bad earth from e01 or e02 from the ecu cause this?

[Ghostyman]

Quick answers without checking any sources (so take with a grain of salt)

mr2 turbo has fuel cut but only when boost pressure is above a certain level. It wouldn't affect starting and shouldn't affect a 3sge.

mr2 3sgte (and possibly 3sge) have a resistor for the injectors. It's mounted on the rear firewall and looks like an aluminum heatsink. If 3sge is low impedance, you'll need the resistor (but I still think it would start).

Not sure about that specific ground.

Are you sure the timing is right?

[bajachris88]

Thanks for the reply mate.

I just found a page that explained the resistor. Yea the 3sge's turned out to have high imp injectors so they don't have a resistor.

The issue i got is that i can get the engine to start momentarily if i spray fuel down the intake manifold... but it won't deliver fuel on its own. That made me assume the timing was alright. and the fuel pump is working which leaves me to think the injectors are being funky. The injectors are getting current, and its going all the way to the computer, which makes me assume the ecu isn't responding right.

Has anyone got a 93 mr2 3sge pinout by any chance? rumour has it they had many variations in the pinouts over 90 to 93...