01' Tacoma ECT Circuit Code: P0115

I bought this truck recently and drove it 3 hours home. The guy told me that the code (P0115) was just a vacuum leak. I should've done my research, I know. The next morning the truck didn't start. I called a few friends and decided that the truck had high miles (279,000) and would probably need a new fuel pump at some point soon anyway, so I replaced it along with the fuel filter. (I didn't hear the fuel pump until after I replaced it)

I go to start the truck and it still wouldn't start, UNTIL I began to gas it a bit and work the gas and the ignition simultaneously. After a few tries it started! Now I wanted to really solve this problem and I ran into a few things.

While looking under the hood, I began to fill the coolant into the radiator and found 2 cracks in it! I could've just used some JB Weld to fix it, but I didn't. I found a good deal on a brand new one.

Now I do some research on the ECT code and found out that if the ECT Sensor is bad, the vehicle won't give an accurate temperature to the ECM, which controls other car components based upon the temperature that is provided to the ECM by the ECT sensor. When a vehicle overheats, the ECM shuts the vehicle off. But if the ECT sensor is bad, it would send faulty readings. This leads to incorrect A/F ratio, which could be why my truck won't cold start.

My biggest worry is that the previous owner was driving this truck while it was overheating and had absolutely no clue what damage he could have been doing because it wasn't shutting off to protect the engine.

I know that was a lot, but I don't know if I'm overreacting or if this is something that is going to be too much work or too expensive to be worth it. If you have any insight to this situation or advice for me going forward, I would very much appreciate it. Thanks, y'all.

 

You do have quite the perfect storm brewing there. I think most here will suggest compression and leak down tests... If those come back fine, I'd just try to drive it and get some miles on it to see what else arises.