Fuel Injectors---computer

[Nole65SG]

Has anybody had a similar experience...I have a 92 SC300. The pulse light is staying on causing the fuel injectors to stay open and a steady stream of fuel into the cylinders. I know for sure that the last three injectors were constantly open. As a result I had billows of smoke out the exhaust and of course the car could not be driven. It appears that the main computer is malfunctioning causing the pulse light to stay on. Anybody had such an experience and did the fuel injectors have to be replaced too?

[AWJ]

What is a pulse light? Check the continuity on the injector. See if you can find a donor ecu to test with. Never got to experience such a thing before. But if 3 injectors are on/stuck open - why would that make smoke out the back constantly? It should kill/flood the engine. Smoke out the back is oil or coolant or both...

[jzz30]

it also could be stuck injectors.... or maybe a coil.. howmany coils do the 300's have?

[GrnHrnt]

it also could be stuck injectors.... or maybe a coil.. howmany coils do the 300's have?

'00 SC300 has 3 ignition coils.

[mehullica]

A pulse light is used at the injector connector to see the duty cycle pulse width. If it is always on the injector is always spraying fuel. It has nothing to do with coils. Only things involved are wiring, ECU. Sounds like maybe a short to ground somewhere on the wiring harness,or ECU. I'd do some pinouts from the connector of the injector to the ECU for conitinuity and continuity to ground also.

[Nole65SG]

A pulse light is used at the injector connector to see the duty cycle pulse width. If it is always on the injector is always spraying fuel. It has nothing to do with coils. Only things involved are wiring, ECU. Sounds like maybe a short to ground somewhere on the wiring harness,or ECU. I'd do some pinouts from the connector of the injector to the ECU for conitinuity and continuity to ground also.

Thanks. We are on that track right now.

[AWJ]

An led for duty cycle. I see. Never was exposed to that sort of thing. Cool stuff. Ok, so the output for injector pulse is staying on. Swap the ecu. Let us know how it turns out. I guess if the engine could stay running with the injectors always open it would smoke like mad. Kind of interesting it even stays running though.

No you should not need to change the injectors when you change the ecu as long as the ecu is the same model number/model year. Avoid a 97+ ecu. The rest should work. But consult the parts supplier to be sure.

I thought the vvti Sc3's had 6 coils. They are 3 coil wasted spark? News to me...

[Nole65SG]

An led for duty cycle. I see. Never was exposed to that sort of thing. Cool stuff. Ok, so the output for injector pulse is staying on. Swap the ecu. Let us know how it turns out. I guess if the engine could stay running with the injectors always open it would smoke like mad. Kind of interesting it even stays running though.

No you should not need to change the injectors when you change the ecu as long as the ecu is the same model number/model year. Avoid a 97+ ecu. The rest should work. But consult the parts supplier to be sure.

I thought the vvti Sc3's had 6 coils. They are 3 coil wasted spark? News to me...

I will let you know the result. Yes, the smoke was tremendous and the fuel smell stifling. The engine locked up very soon thereafter. Tremendous pressure built up in the cylinder. Gas shot 8 feet in the air when pressure was released. Not your typical repair!! Thanks for the info on ECU.

[jzz30]

ouch! we had an sr20 injector leak and lock the engine and shortly after there was rod knock!!!