Diagnostic codes 10, 13, 12 and 18?

Hello,

OBD1 fault codes are not very descriptive

10 - cylinder #1 failed cylinder balance test
12 - Cannot control RPM during ER self-test high RPM check
13 - Cannot control RPM during ER self-test low RPM check
18 - IDM circuit failure or SPOUT circuit grounded
or
18 - SPOUT circuit open or spark angle word failure

The IDM is the signal that comes from the ignition module. The Spout is the spark out circuit you remove to set timing.

It looks like you might have an ignition module problem or possible crank shaft position sensor issue.

Hope this helps.

Cheers, Boris

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?

Hello Raj,

Thanks for the above information.

Backfire in exhaust could be caused by a lean mixture.

I would suggest checking the fuel pressure regulator first.
If you pull off the vacuum pipe is there any fuel present in the port?
If yes, then you have a faulty regulator diaphragm.
Next check when the engine faults, pull off the vacuum line and blank it off.
This should then increase the fuel pressure to supply maximum.
We could have a faulty PRC solenoid valve

A good video on testing to valve:
https://youtu.be/ucOq-83Hv2Y?si=TskTnryViXW0obkr

Fuel pressure specification:
W/O Vacuum: 38-45 psi (2.7-3.2 kg/cm2)
W/ Vacuum: 30-36 psi (21.-2.6 kg/cm2)

How to carry out fuel pressure test:
https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

A video for a Mazda 626:
https://youtu.be/kVzYrBjP_CY?si=p8AGDy7jz6Oixp51

Hope this helps.

Cheers, Boris

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.

If i can jump in here. I have seen a bad TPS sensor cause this issue without generating a code. So, does the car have no codes now? Let's clear the codes and then run the engine and gather the codes again please.

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.

Sounds good, I have seen a bad TPS cause this.

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.

What is the car doing now, has anything changed? Can you please shoot a quick video with your phone so I can hear the noise? That way I can tell for sure what's going on. You can upload it here with your response. We need to hear the noise, so we know which direction to go to help you fix the car. It takes time to upload so please be patient. Also, I would service the throttle body as well, it sounds like the car might be in limp mode.

Please go over these two guides:

https://www.2carpros.com/articles/throttle-actuator-service

and

https://www.2carpros.com/articles/reduced-power-limp-mode

Please go over these guides and get back to us.

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.

BORIS K is one or your best! You are welcome, please use 2CarPros anytime we are here to help.