mbsmith

Ok so ive been doin some searching and decided to start a new thread. I have a 1993 sc300 with 175kand miles. Recently it has had new alternator, battery,plugs,wires, distributor, timing belt,water pump, fuel pump, fuel pump ecu, ignitor, and maf. It runs great then all of the sudden the rpms drop, it smells strongly of gas, and it will die. Its really random sometimes it will do it on a cold startup and sometimes while im driving. When its not on ( the cel) the car runs amazing so this leads me to believe it has to be something electrical like a sensor . Does anyone have any ideas as to what it could be? Ive tried checking the cel but it just continually blinks with no pauses so i would assume that means no codes? From all the searching ive done on here it seems like many people have had the same issues and all were able to remedy this by bypassing the fuel pump ecu. In my case that didnt work. I installed one yesterday from a working car pulled the fuse i installed in the fusable link in the diagnostic port under the hood and it still wont run. Any input would be greatly appreciated

Ali SC3

iTrader: (10)

the other person who had a CEL but it just blinked at them (no codes), it turned out to be a faulty ecu. If the CEL is on, it should give you a code.

mbsmith

Ok well i believe im back to the maf. The one i purchased was used so im hoping thats the culprit. I say this because while its running i can unplug it and nothing changes. What do you think?

Ali SC3

iTrader: (10)

you can test the resistance with an ohmmeter, seems like you have replaced enough stuff I wouldn't replace the maf twice. it is unlikely that both mafs are shot, but i guess it is possible. You have a symptom of a bad ecu though, and if your ecu is bad that could explain why unplugging the maf does nothing. see if you can borrow a friends ecu for an afternoon and give it a try.

here is the thread where the bad ecu just constantly blinked, granted its a 400, but same symptom.
https://www.clublexus.com/forums/per...-92-sc400.html

also check and make sure the rotor and cap on the distributor are in good shape. they can cause similar issues.

mbsmith

Thanks for the link. I checked the resistance in both of them. Both checked good. Im hoping to grab another ecu to test tomorrow. I also had another set of plugs so if i have time tomo.rrow i am changing plugs and new vcg . Thanks for the pointers, ill let ya know the results