1NSIGHT

Hello everyone

This is my first post to this forum and Im hoping you could help me out. My 94 sc300 does not register engine malfunctions... i think. Since I bought the car about 10months ago to replace my FC3S as my daily I have had no mechanical issues with the car. I have had electrical issues which I fixed. My fuel pump ECU and Ignition Control Module failed at the same time. (Not having spark or fuel at the same time and intermittently is a mother Fing nightmare to diagnose).

So my new problem is that after have a sharp decline in fuel mileage for 22mpg - 17mpg average (this is not due to winter gas blend) and failing emissions, I have been trying to see what is wrong with my car. Currently I am using the diagnostic port to keep the fuel pump running, and the airbag light is on. (Been running fuel pump like this for months no issue)

So my car has been running the same since this recent gas mileage drop but now Im trying to fix it and I cant get any CELs even if I try to force one like unplugging a sensor.

What is wrong with the car where CELS dont show, even when you try to make a failure appear?

Dx3

iTrader: (13)

Have you actually pulled the codes and they aren't showing any? Or just the light hasn't come on?

1NSIGHT

Both... CEL just constantly flashes.

Just to make sure......
Key in ignition, car in neutral, accessories off, then (te1, e1).

Vrank

iTrader: (4)

if the light isn't on when driving and flashes constantly when jumping te1 and e1, then you have no codes. Which sensors have you unplugged to try to force a code? try the maf. Sounds like you have leaking capacitor issues in your ecu.

running the pump in the diag box is retarded. pull the side panel off behind the driver seat, find the fuel pump ecu and clip/twist together the black/red stripe and green/red stripe.

1NSIGHT

I pulled the tps sensor and an o2 sensor drove around a few miles to force a code. the car drove crappy so I know the ECU recognizes the fault. Just wont show a code.

I have fixed the the fuel pump issue properly. I ran the pump through the diag box because it was easy and effective. I'm beyond mechanically adept and would appreciate not being referred to as retarded.

Vrank

iTrader: (4)

Didn't say you were a retard, just that running the pump through the diag box is. It's a shortcut, it's half ***, it's for lazy people, diagnostics, or for getting by in a pinch. Back on topic though, sounds like your ecu is on it's last leg. It's common. Pop it open and have a look. Caps are cheap and simple to replace. I'm retarded and I've fixed a few of em.

1NSIGHT

I'll try pulling the ecu and looking. I need to pass emissions and I replaced the o2 sensors in a last effort but that didnt work and Im looking into a new cat now.