EvanBlank

I have a 95 Lexus SC300 with a manual swap. My car was in storage for about 3-4 months and would start and run every once in a while. I tried starting it and it would run but then mysteriously die about 20-30 minutes later.


My first thought was fuel because I would still get little pops when I sprayed starting fluid. so I did the 12v fuel mod and now I bypassed the fuel ECU. **Ran 20 minutes, then died and wouldn’t start again**

Then I thought it may be a bad ECU so I pulled the ECU from the car to find that I didn't even have a sc300 ECU in my car! it was an ECU for a manual 98 Toyota supra. I also discovered that I had two blown capacitors. (which I believed was causing my random no start problems)

Blown Caps


New ECU


After discovering all this I did some research in the forums and found out that the best ECU I could get to replace my own (especially because of my manual swap) would be a manual 95 Lexus sc300 ECU so I ordered a used one from a reliable source and started to replace the bad one. With the new ECU in I turned the key and still no start. But something I did notice was the Cel was lit up. Codes 12 and 14 were being thrown.

12- Rpm signal fault

14- ignition signal fault.

Continuing research on how to test parts in the ignition circuit to see if they are giving correct voltages I checked for spark. Grounding the plug that goes to the distributor and as I turned the car over I got no spark between that and the frame.

So now I KNOW Spark is my issue. I went straight to testing my ignition control module and ignition coil to ensure that they are both receiving the proper voltage. both seemed okay but I decided to make sure. So I replaced both the coil and module. Still, no start so at this point I am extremely lost as to what the issue could be and I am turning to the forums. People keep telling me it could be a bad crank sensor but I am pretty sure my year didn’t have that sensor and everything takes place in the distributor instead.



Summary of everything above:
**random sometimes starts but wouldn't run for long before dying, then wouldn't start again**
-12v Fuel Mod
**Ran 20 minutes**
-Replaced ECU
**no Start and Cel threw 2 codes**
-No spark
-Replaced Coil
-Replaced Module
-Must be a Permanent/Hard Code because it won't clear by removing ECL Relay or disconnecting negative battery terminal
-Distributor Cap and Rotor both look good (no corrosion)

This is my first post in over a year so I apologize ahead of time if my writing is hard to follow. I also may be forgetting some things.

Any input at all would be greatly appreciated!!