Start and Stall
 

My 1992 sc300 has been going through plenty of problems lately. It all started with the turn on and then it flooded and turned off when cold. Then I purchased a new ECU and that stopped the fuel system being on constantly but still no start so I did plugs and wires, same outcome no start as if it was flooded So I unplugged the fuel injectors and it started right up and burned off the fuel. Then my friend told me about the coolant sensor. I replaced that and the car No longer floods itself but now When I start the car it comes on then sputters and dies unless i stay on the gas and it runs terribly still. I then unplugged the Maf to see if that was the problem and it ran worse and barely started so i cleaned it and then I tried the TPS and unplugged that. The idle was even more horrible. So now Im thinking there's something wrong with my fuel system or maybe I have to do the 12V fuel pump mod.

Welcome to the forum . Since you are new to our forum , I am moving this to the Performance & Maintenance instead of deleting it .

I would suggest do a lot of reading and familiarize yourself with the forum rules and what is written on the stickied threads on the main SC page.

Good Luck !

Oh I apologize for this and thanks!!

***Update*** Tried to do the 12V mod and it was already done. Really don't know what else to check. Everything is replaced and I went through the Sticky looking for idea's. I also tried searching old post for the same problem but all of the old post says to check the ECU or do a 12V mod. Iv'e swapped between 2 ECU's and both the same response just really rough idle and instant stall

The coolant sensor has nothing to do with the injectors flooding your cylinders. From a cold start , even if you unplug that sensor , a good running car will start because the ECU will go into a mode assuming that the sensor is bad so it will start the car. It is mostly needed on a hot start meaning when the engine is warm. It needs that coolant sensor.

If it floods the cylinder , then you know there is nothing wrong on the fuel system (pump) since there is fuel delivery . That means with or without the 12v mod , your problem is not on that area.

The info / diagnostics you mentioned above is all over the place . Some stuff you mentioned has no relation with one or another problem . So the last info I read is the car starts but idle is bad .. is that right ? I assume the car stays running now ,it is not being flooded and it is just running poorly ?

That can be a lot of things ..make sure fuel filter is clean just to make sure you have a good fuel delivery . I assume it is clean since you were flooding the cylinders. Now check the plugs , coil and distributor.

And where did you get your 2nd ECU ? Was it guaranteed to be in good working condition ?

Thanks for the reply! I actually looked into it farther and the 2nd ecu was repaired by driftmotion so it's in good working order like my first one but we seen there was a little gash on the timing belt! I decided to advance the timing and the idle got a little better and I was able to put it in drive and the car didn't bog out or die under load! I'm deciding to get a timing light and see if it jumped timing because if that's the case it explains so much.