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[Muroman]

Hey,

-99 MV6 left me on road

Traction control was working as I was accelerating hard and then power went down and then engine shutdown.

Paperclip gave
73   Mass Air Flow Sensor Voltage Low
74   Mass Air Flow Sensor Voltage High

Is this clear MAF case?

Engine is running roughly and will eventually shutdown. Starts but will not run.

Also it's about -15-20degrees in Finland now and I filled her up 10min before incident. (Had to check from receipt if I put diesel into her but luckily no  )

[terry paget]

Sounds like MAF to me.
Unplug the MAF and see if it cures the fault.

[TheBoy]

As implied, if it won't run right now, unplug MAF, and see if it runs OK-ish.  If it does, MAF is likely...


...but a failing crank sensor can throw erroneous MAF codes, so also keep a very close eye out for 19 codes.

[Muroman]

MAF unplugged runs ok-ish yeah. I must admit I have never ever seen Omega running with engine light on so is it normal for it to like blink very quickly? It's like not glowing all the time it's blinking very high frequency.

Edit: now it runs with MAF plugged the same way as with it unplugged??

Is the crank sensor the one near oil filter?

[TheBoy]

Yup.

Given the EML behaviour, just check battery voltage at 2000rpm first.

[Muroman]

It's giving 14,1V and that is normal, atleast that is what it has always given

[TheBoy]

That's actually a bit low, but wouldn't cause a problem with the engine.

Do you have the facility to check the trims - both idle and part load trims should be close to 127.  Just wondering if its trimmed itself so far out of tune, it can't run successfully. This is likely to cause revs to be erratic, and it slowly dies.


Crank sensor failure tends be a sudden loss of all power, as if the engine just cut. Often, with a failing crank sensor, if you let it cool, it will start and run until it warms up, then suddenly cuts again.  That doesn't quite match your initial description, which is why I'm hesitant to say its defo crank sensor without exploring other possibilities first.

[TheBoy]

Also, on a older V6, inability to idle, but running fine when running above idle, is frequently a sticky ICV, which can normally be cleaned rather than replaced.

[Muroman]

Okay, I dont have any tech 2 or so but if they are out of tune what needs to be done?

ICV=idle control valve? It is cleaned frequently anyway and last cleaning under a year ago but will do that. Also it's running roughly on higher rpms too.

[TheBoy]

If trims have badly drifted off centre (for example, due to airleaks in the intake or in the exhaust generally before the cat), the engine ECU may be over or under fuelling, causing poor running.

[Muroman]

I surfed around internet and bumped into exactly similar story as mine (strobing EML light .etc) and the reason was broken coil pack, so I think my best choice of multiple ~100eur guesses is to choose the coil pack for starters....

[TheBoy]

Check HT leads and plug wells before condemming CP.  CP usually show visual signs of breaking down when they start to fail.

[Muroman]

Measured ht leads, ok. Changed coil pack and spark plugs. No work   

Ordered MAF, changed it and she runs well 

Well atleast it's working now and also I have a spare coil pack and plugs were changed