HAWKEYE Diagnostic readings

**onebob** · 17th February 2018, 02:26 PM

Checked the MAF a few days ago - plugged in the HAWKEYE and at idle the MAF reading was fluctuating 50-49. I understand from a past sierraferry post that a good MAF should read between 55-65. I have a de-EGR’d 10P TD5 with TRS “chipped” ECU

Checked the MAF again today but this time whilst mobile ....... in 3rd gear (autobox) at 3000RPM and under load up a long steep hill. The airflow peaked at 440. My research has found some 9 year old forum posts where it was said that between 550 and 650 was expected for a good MAF. My AT shift changes have become a bit “fuzzy” and drawn out so a new MAF is on the cards methinks....

**sierrafery** · 17th February 2018, 05:53 PM

Unplug it and go for a drive like that...if you like it more this way you need a new one, eventually before spending on it do some things which might restore things: clean it with dedicated MAF cleaner which can improve it or ruin it completely, clean the MAP sensor as to release the hole near that probe cos there's the pressure sensitive piezocrystal, put a new air filter if it's old, another thing which can reduce the high end readings is the depression control valve cos if it doesnt close well the air flow through the MAF is reduced due to excess of crankcase pressure behind it, if you know it's old put a new one cos you can't check it other way

**onebob** · 17th February 2018, 06:57 PM

Thanks SF, the depression control valve and air filter are recent replacements, MAP sensor i cleaned recently when i installed the boost take off nipple into the inlet manifold... will unplug MAF and go for a drive .... more soon.

NB: the ambient and inlet pressure readings are similar at idle - inlet pressure slightly higher.

**onebob** · 18th February 2018, 10:34 PM

Cleaned the MAF today and gained a marginal improvement .... readings at idle are now cycling 53 - 52 - 53. My MAF is a Siemens and maybe original for all i know. I’ve had the D2 since 2010 and have never replaced the MAF. I’ll do the “unplugged” test next...

**onebob** · 19th February 2018, 10:21 AM

Drove to work this morning (85kms) with the MAF unplugged and the difference i immediately noticed is that i can now feel positive TC lock up in 3rd and 4th. Shifts seem to be earlier but maybe I’m imagining it...
Will trial it for a few more days.

**sierrafery** · 19th February 2018, 10:52 AM

Go one way with MAF unplugged and back with it plugged then you should realise if there is a difference

**onebob** · 20th February 2018, 11:06 AM

Thanks SF, i followed your advice and can confirm that the torque converter lock up function is the most noticable difference with MAF plugged vs unplugged.

**laney** · 20th February 2018, 07:39 PM

Onebob when you plugged your hawkeye in did you get a fault code as I am getting a fault that says low air flow 3011 are you getting this to date I haven't changed my maf but will be soon as the maf is as old as the car hoping this will fix the code.

**onebob** · 20th February 2018, 09:10 PM

Yup

after unplugging the MAF the HAWKEYE showed “Fault: 3014 airflow low fault logged” Otherwise the only other fault code I have seen is “overboost”

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