Electrical problem 940

[TonyS9]

What is Alternator voltage with lights on?

Review questions

1. Have you established if it is spark or fuel related, can you check spark at plug with light indicator while engine is running?
https://www.youtube.com/watch?v=eQBtzk-dGYM

2. There are reference in the thread to white and black spark plugs, which is correct?

3. Did you measure fuel pressure?

4. Did you try an injector comparison test ?
Unplug each injector, 1 at a time while the engine is running and see if each one makes the same difference in roughness. If it makes no or less difference than the others, that injector is a problem.

[Ammorack]

Originally Posted by TonyS9

What is Alternator voltage with lights on?
14,4v
Review questions

1. Have you established if it is spark or fuel related, can you check spark at plug with light indicator while engine is running?
https://www.youtube.com/watch?v=eQBtzk-dGYM

2. There are reference in the thread to white and black spark plugs, which is correct?

3. Did you measure fuel pressure?

4. Did you try an injector comparison test ?
Unplug each injector, 1 at a time while the engine is running and see if each one makes the same difference in roughness. If it makes no or less difference than the others, that injector is a problem.

14,4v

I don’t have spark plug indicator light! Is there any other way or do I have to get one? I have checked spark at plugs and they produce blue/purple spark.
But I haven’t tools to check spark at plugs.

Spark plugs are black and sooty on idle. Above 3000rpm the plugs are white. I have checked after 30 min driving above 3000rpm. And on idle for 30 min while holding gas pedal so the engine doesn't stall.

I measured fuel pressure some months ago. I don’t have tools to check fuel pressure right now. But if I remember correctly. It was 2,5-3.0bar

Unplugging each injector one at a time does indeed change in performance. It doesn’t stall when I unplug one at a time. It can run with two injectors unplugged.

[Laird Scooby]

Ammo - have you, or a previous owner, removed the inlet manifoldat any point in time? Was a new gasket used on refitting? Also have you checked the manifold securing nuts are tight?

[Ammorack]

Originally Posted by Laird Scooby

Ammo - have you, or a previous owner, removed the inlet manifoldat any point in time? Was a new gasket used on refitting? Also have you checked the manifold securing nuts are tight?

I have changed the inlet manifold gasket just to be sure it wasn’t bad. Nuts are tight.

[Laird Scooby]

Originally Posted by Ammorack

I have changed the inlet manifold gasket just to be sure it wasn’t bad. Nuts are tight.

Check them again to make sure.

[TonyS9]

Originally Posted by Ammorack

14,4v

I don’t have spark plug indicator light! Is there any other way or do I have to get one? I have checked spark at plugs and they produce blue/purple spark.
But I haven’t tools to check spark at plugs.

Spark plugs are black and sooty on idle. Above 3000rpm the plugs are white. I have checked after 30 min driving above 3000rpm. And on idle for 30 min while holding gas pedal so the engine doesn't stall.

I measured fuel pressure some months ago. I don’t have tools to check fuel pressure right now. But if I remember correctly. It was 2,5-3.0bar

Unplugging each injector one at a time does indeed change in performance. It doesn’t stall when I unplug one at a time. It can run with two injectors unplugged.

Spark plug lights are a cheap tool for eliminating spark issues almost completely. A set of 4 put on the plugs and the engine run will allow you to monitor the sparks in all rpms and during fault condition.

The unplugging of injectors is meant to have a roughness, the point is to compare how rough the engine is for each injector you disconnect. You also need to check the fault condition.

Maybe you could put a video on youtube of the engine idling roughly or limiting on the rpms? Is rpms still limited?

The indications to me are a weak mixture, and roughness-stalling can be a missing injector or low fuel pressure. You maybe need to measure or log these dynamically or during the fault condition.

Going back to the error code, are you still getting this? You mentioned 212 Heated O2 missing or faulty. This is different to weak/rich at the wrong time., you only got this code? Seems there is something wrong with the wiring there, but I'm not exactly sure of the meaning of the code either.

[Ammorack]

Originally Posted by TonyS9

Spark plug lights are a cheap tool for eliminating spark issues almost completely. A set of 4 put on the plugs and the engine run will allow you to monitor the sparks in all rpms and during fault condition.

The unplugging of injectors is meant to have a roughness, the point is to compare how rough the engine is for each injector you disconnect. You also need to check the fault condition.

Maybe you could put a video on youtube of the engine idling roughly or limiting on the rpms? Is rpms still limited?

The indications to me are a weak mixture, and roughness-stalling can be a missing injector or low fuel pressure. You maybe need to measure or log these dynamically or during the fault condition.

Going back to the error code, are you still getting this? You mentioned 212 Heated O2 missing or faulty. This is different to weak/rich at the wrong time., you only got this code? Seems there is something wrong with the wiring there, but I'm not exactly sure of the meaning of the code either.

I only got this code for missing o2 signal faulty or missing. Makes no sense. I can indeed post a video today

[Laird Scooby]

Originally Posted by TonyS9

The indications to me are a weak mixture, and roughness-stalling can be a missing injector or low fuel pressure.

It could well be that Tony, the brake servo hose etc hasn't been checked AFAIK.

[Laird Scooby]

Originally Posted by Ammorack

I only got this code for missing o2 signal faulty or missing. Makes no sense. I can indeed post a video today

That can be cause by an air leak into the inlet manifold. The ECU detects a lean mixtuer and adjusts the fueling accordingly (makes it richer) but the Lambda sensor is still reporting a weak mixture from the air leak so the ECU richens the mixture further but because of the air leak, the Lambda still doesn't register a change and this keeps happening until the ECU determines the Lambda sensor isn't responding as it should and must therefore be faulty.

Can you post a photo of the engine to include the MAF and inlet manifold, a couple of close ups of each end of the hose between MAF and throttle body, top and bottom of the inlet manifold to cover all areas of both and also the brake servo hose.

[taiwan740]

The indications to me are a weak mixture, and roughness-stalling can be a missing injector or low fuel pressure.

Fuel pressure regulator perhaps? if the diaphragm has failed usually that causes fairly consistent rich-running though as far as i know.