QuestionQUESTION: I will keep this as short as possible.
1990 Seville 4.5L MFI, 200,000 + miles, mechanically sound engine.
I recently had to change the water pump and water pump inlet. While doing this I also changed the timing chain and camshaft thrust bearing. The car ran great for about a week and then was hard to start. The starter drive would kick out almost immediately nearly every time. Every now and then it would crank, but would not start. Eventually, it would start but run rough. I would have to keep the RPM around 2000 until it would finally smooth out and idle. I killed the engine and notice that the engine smelled hot, but I could immediately restart the engine and it would run great without any incidents. This process continued for two more days and then refused to start at all. I replaced the ignition coil, cap and rotor and the car started right up and ran great. I drove about 8 miles and stopped the car for about 20 minutes. The car started up great and ran fine for about 10 miles when I notice a slight muss that lasted for 3-4 seconds and I got a Service Engine light. The error code was E023. I drove for another 30 miles and stopped the car. I checked the error codes - engine off, key on and I had E023, E052 and E074. All codes showed to be in History. A few hours later I tried to start the car and the previous no start condition returned. The car has not started since. The error codes are now E052 and E074, both in History. I checked all the fuses and all are good. Those under the hood, in the glovebox, and under passenger side dash. I changed out the ECM with a pull from a salvage yard and I continue to get the exact same symptoms. My ECM and the pulled ECM both used the PROM 1020 and I tried both PROMS, with the same results. I have confirmed that I am getting spark to the two spark plugs I checked, but the car will not start. Any suggestions on what to try next would be greatly appreciated.
ANSWER: E052 is caused because you removed battery voltage from the computer.
E074 is caused by an intermittent MAT (Manifold Air Temp) sensor. You might have disconnected it and forgot to plug it in and tried to start the car and then noticed that you forgot to plug it in and it already set the code.
Lets CLEAR ALL the codes from the computer and see if any codes return.
1. Re-access the computer codes and when you see ECM?
2. Push and release the HI (fan up) button and you will see ECM DATA?.
3.keep pushing and releasing the LO (fan down) button until you see ECM CLEAR CODES?
4. Push and release the HI button and you will see ECM CODES CLEAR.
5. Wit 3 seconds and turn OFF the ignition .
6. Wait a minute or 2 and reaccess the computer and see if any of the codes return.
If NO codes return, Check your fuel pressure.
---------- FOLLOW-UP ----------
QUESTION: I cleared the codes and the codes in History did not return. I do have a B120 code that shows as current and was not there before. What does this code mean?
AnswerB120 is a twilight system potentiometer failure. You will need, If necessary, Electrical schematics and picture locations of the components within the system that is causing you problems of which can't be done on this website which only allows one picture. I do not have a website so you will have to e-mail: onlineautohelp@msn.com in order to obtain the information.
The biggest help for me to help you would be if you could take video of your problem and e-mail it to me.
