D5 (D5244T to 2005) Starting issue, rough running

[cheshired5]

Test the glow plugs. There's a recent video on my YouTube channel showing how to do them in situ.

On a stone cold engine with only ignition on get the:
Ambient temperature from the dashboard
AND
Then from ECM Parameters:
coolant temperature reading
Intake air temperature
Intake manifold pressure
Atmospheric pressure
Mass airflow

Then the same 5 readings ^^^^^ at idle

And again at 1k, 2k, 3k and 4k revs

You can run up to 10 simultaneous Parameters so you can have all the readings on one screen to screenshot.

[harrympotter]

Thanks Cheshired5 another amazing video, so informative, I am actual learning.

Glow Plugs (pulled one out) they are NGK YE12, all 5 with the same ohms resistance of 1.3 ohms. which the internet tells me is correct.

Disconnected the Coolant temp sensor. Turned IGN on, 12.2V at each plug cap lead, approx 20seconds later I hear a click from the fuse box (relay) and the volts drop to zero.

Requested data attached as screen shots. Dashboard Temp 8 degrees C.


As normal struggled to start, five seconds of cranking, today she would not idle (stalled), third attempt, started and she did idle. White ish unburnt exhaust smoke present throughout.

Accelerator peddle to the floor, I can't raise the RPM past 2700/2800 RPM.

In all REV ranges I do not have a MASS AIR FLOW Sensor reading (MAF Plug is connected.

Is that a dead MAF or do we need to test wiring? Signal voltage?
Thanks in advance.

[cheshired5]

Originally Posted by harrympotter

Glow Plugs (pulled one out) they are NGK YE12, all 5 with the same ohms resistance of 1.3 ohms. which the internet tells me is correct.

Vida should have the exact ohms.
For example, my 2002 D5244T plug is 0.685 (@20°C) which when you add 0.1-0.2 ohms for leads resistance gives the 0.8 meter reading you see in the video.
I think you'll find that yours are over slightly but not in a way that makes any difference so I'm just pointing it out for accuracy and to trust Vida and not the Internet in 99.9% of cases.

I suspect the unburnt fuel is because there's no accurate MAF data for precise fuel delivery.

Originally Posted by harrympotter

In all REV ranges I do not have a MASS AIR FLOW Sensor reading (MAF Plug is connected.

Is that a dead MAF or do we need to test wiring? Signal voltage?

You'll need to test the contacts inside the MAF supply plug with ignition on and Vida should confirm what to expect in Information >Product Specifications >Specifications Electrical/Electronic
I would say that if you can get 2 good grounds and a 12v from the MAF plug contacts, the wiring is good and the MAF sensor itself is dead and needs changing.

I have a genuine Volvo/Bosch used but known working MAF which I could send you for £30.

It has 5 pins and carries the Bosch number 0 280 218 088 and the original Volvo part number 8670115 so you'd need to confirm the part numbers printed on your MAF and the number of pins.

[cheshired5]

Forgot to mention to also try starting with the MAF sensor unplugged to see if there's any difference.

[harrympotter]

Thanks,

I tried a start with MAF plug off, unfortunately still poor starter and running.

VIDA MAF plug specification reads pin #2 = 12volts. Pin #4 = 5volts.

I have no ways of knowing plug/pin orientation numbers?

Sadly, I only have 5 Volts @pin #2 & #5. ?

[cheshired5]

Ok.
I'm pretty sure mine has the same layout and I have no running issues so I'll try to check mine tomorrow so we have a reference from a known working plug.
If my working wiring shows the same as yours, your MAF is faulty.
If my working wiring is different, you have at least a wiring issue.
Your IAT sensor is built into the MAF and is giving a credible reading as is the plug feed but as airflow and air temperature are 2 different circuits, it's not unusual to have one aspect of the MAF unit working correctly and the other not.

In the meantime, can you confirm which of your plug contacts are ground and not just 0 volts.

Use the permanent live post under the flap near the engine bay fuse box.
Then with your multimeter on DC volts, put the red multimeter lead on the live post and with the multimeter negative lead, probe the plug contacts.
Any grounds will show battery voltage on the multimeter.

[harrympotter]

As requested volts test for earth,
Red lead live positive terminal, black probing. IGN off.
#1 12.55V
#2 12.55V
#3 12.55V
#4 0.01
#5 12.55V

As per pic #1 left #5 right.

[harrympotter]

The more I think about it, 5V is an acceptable power supply to the MAF & IAT . Pin #2 5v & pin #5 5v.

This could be a VIDA Spec typing error? Why do you need a 12v supply, no heater involved.
If I have a break out box to measure the signal Voltage back to the ECM, I'd be looking in the region of UBAT (DC V) signal 1.03V @ IGN on, to 1.67V @ idle.

5V is a very common supply Voltage to various systems that require a return signal, 5v seems enough? Did anyone have 12volts supply at the plug?

[cheshired5]

These are mine.



Meter Positive on Positive Post No Key
Meter negative probing
1 Battery voltage
2 Battery voltage
3 Battery voltage
4 Battery voltage
5 Battery voltage

Meter Positive on Positive Post Ignition on
Meter negative probing
1 Battery voltage
2 6.8
3 Battery voltage
4 0.005
5 6.8

Meter Negative on ground No Key
Meter Positive probing
1 0v
2 0v
3 0v
4 0v
5 0.010v

Meter Negative on ground Ignition On
Meter Positive probing
1 0.0007
2 4.99
3 0.006
4 Battery voltage
5 4.99

[harrympotter]

Great thanks,

I have an issue with #pin 4,
And or including wire #4. Or the source of volts for #4.

Test one, #4 you have BATT V, I have zero.
Test four, #4 you have BATT V , I have zero.

I'll do some wire continuity checks, fuse checks, and ideally find the source of this BATT V (probably ECM).