Diagnostic codes 10, 13, 12 and 18?

Thank you, Boris, for your quick reply.

I have learnt something new today. I disconnected the TPS and found a new code 0123 in addition to the previous code. The description of this code matches the OBD2 codes. So, the previous code is for the knock sensor.

I removed the knock sensor and found it damaged. I will reply again after replacing the part.

So, the Ford Laser 2001 KN/Mazda Protege 2000 BJ 1.6L ZM engine

Doesn't have the OBD port under the dash.
The 25-pin port is in the engine compartment.
The LED lamp can be used to retrieve the codes.
They are 4-digit OBD2 codes.

I hope the above info is useful to the forum readers.

Cheers,

Raj

Sorry Boris for not getting back to you sooner. I was busy with some other work and couldn't find time to spend on this car.

I have replaced the fuel pump, spark plugs, ignition leads, coils, CPS and the knock sensor. The problem continues as I described earlier. Just to recall, the car works fine until the coolant temperature reaches the normal temperature. Then after stopping at traffic lights and taking off, the problem starts. Pressing the gas pedal doesn't accelerate and the car moves very slowly. I have to pull over the car and drive slowly at 2000 RPM until it picks up the speed.

After replacing the knock sensor all codes have been cleared. No more codes coming up.

I do get backfire via the exhaust. The fuel filter was also replaced. Can something be wrong with the fuel regulator or the Fuel Pressure Regulator control valve?

Thanks Boris.

I measured the fuel pressure. It's zero. I also feel the vacuum at the regulator vacuum hose. There was no change in the fuel pressure even after disconnecting the hose from the regulator.

There is 12v at the fuel assembly connector. The car is starting as usual. I think not enough fuel is pumped.

Sorry Boris, I didn't get the fuel pressure because I wrongly connected the fuel pressure gauge between the pump and the regulator. I found the correct readings when I connected the gauge to the supply line. The readings are 30 PSI with the vacuum hose attached and 40 PSI with it detached. The pressure holding is okay after the engine is off.

I also took the readings when the engine reached the operating temperature. It's the same as before.

What could be the next thing in this troubleshooting?

The knock sensor was bad, and it was replaced sometimes before. The 1st cylinder compression is 140 psi whereas 150 psi for the other three cylinders. I doubt the knockings caused any bending to the piston connecting rod of the 1st cylinder leading to the problems of power loss and backfire.

Hi Boris, Merry Christmas to you.

I checked whether the gas pedal responded in the neutral position during the hesitation, but it did not give RPM. I would also like to know which sensors could malfunction without throwing trouble codes and whether their output signal is based on the coolant temperature.

Thanks Ken. I scanned and found no codes. Disconnected the battery for 30 minutes to clear the codes. Ran the engine and scanned again. No codes.

I will replace the TPS and let you know the result.

Hi Ken, Happy New Year to you.

I changed the TPS and MAF with used ones removed from a working same-model car. Unfortunately, the problem persists. Checked the Catalytic Converter for clogs. It looks ok. It looks hard to find where the problem is without the troubleshooting codes.

Please tell me what the next step is.

Hi Ken and Boris,

I took the vehicle to a diagnosis centre and they found that one of the ignition coils was not firing when the engine reached operating temperature. This was unexpected as the coils were only a month old and I had checked the sparks. However, I had not checked the spark when the engine was hot and I am unsure if I could have done a test when the engine was hot.

I replaced the coils with brand-new ones and now the car is running well. Before this diagnosis, I had cleaned the throttle body, MAF sensor, and catalytic converter, and replaced the fuel pump, fuel filter, ignition leads, spark plugs, and timing kit, although these changes did not seem related to the issue. After spending money, time, and effort, I succeeded in fixing the problem.

I would like to thank Ken and Boris for your valuable time and suggestions. I hope this experience will be useful to anybody who has a similar problem.