A Few Questions - Advice Needed!

[P6UL K]

Evening all,

I've just recently acquired another Mk3 8v GTi after straying away for a while and i'm having some issues i hope you fellas (and girls?) maybe can help me with...?

I filled the car up the other day and upto today i've done 165miles on three quarters of a tank!!  Now surely this can't be right?!  The 165 miles have mostly been motorway miles.  When i bought the car i serviced it oil, all filters, plugs, leads, cap, rotor arm, cam belt and tensioners, water pump, oil pressure switch and cam position sensor as it had that typical 8v stalling issue. 

I've 'used the search' and i have a vague recollection that some of the engine sensors can cause serious over fuelling? My mechanic friend read the ECU fault codes of which there were two...

01247
00625

The search has shown 01247 to be the Air Intake Temp Sensor?  The one in the airbox?  Is that right?  The scan showed that the air intake tempertaure to be 129c!! ha ha

Also the search had shown that replacing the Oil Temp & Water Temp sensors might also help the over fuelling issue?

Theres also a slight flat spot inbetween 2k and 3k revs?  And the tick over sits at 1k?!

Can anyone advise if any of this is correct or maybe advise on anything else i should do...?

Thanks!

[Seanl]

Air temp sensor being your Mass Airflow Sensor - Just behind your airbox. Unplug it and go for a quick spin. If your flat spot goes, its that. You may be able to get away with removing it, and very carefully spraying it with contact cleaner and a cotton wool bud to clean it up. It cured mine, and many others too. Idle is normally between 900, and 1k so wouldnt be too concerned with that, but what is your engine code and does it have an ISV? Oil and water temp sensors will cause low MPG so worth changing them as their very easy to do, and cost very little anyway. Other than that the only thing I can suggest is to clean throttle body, and all intake pipes out. It will help a little with all the problems you have said anyway. Economy isnt great tbh and 2-3 hundred on a tank is about right depending on where and how you drive. 

[P6UL K]

I thought the air temp sensor was the one that was actually in the side of the airbox?  Nothing to do with the MAF AFAIK as thats the big circular sensor inbetween the airbox and inlet manifold?!  Think your mistaken on that one.... or i am.

Engine code is AGG.

I'm getting some carb cleaner tomorrow and cleaning the MAF and TB was my next port of call after sorting the sensors out.

Thanks for your reply tho

[Seanl]

Yeah sorry my bad, was thinking too much before reading the question properly!! You seem to be on the right track with it all though and I suppose thats why you have had few replies. Just a case of hit and miss as is usual for all fault finding. Hope you get it sorted mate.