Possible Map Sensor fault

[Tony C]

well i hope it aint gona be a common prob each winter,

will silicone sealer do for now until i can get a hot glue gun???

[rob@vems.co.uk]

I wouldn't use any silicone sealer anywhere in a car, just because of the off-chance that it will pollute your wideband sensor.
If you're going to replace that MAP sensor - and you're going to use a Paxton - consider the 3bar sensor: http://shop.vems.hu/catalog/bare-sensor-p-141.html?osCsid=a575192e2768ed41ad489b81ca0cf49d

It has been a particularly cold winter, so its possible that there's moisture issues, saying that my Wife's boost sensor went on her 6 year old TDI so these parts can, and do, go wrong.  I had a Greddy boost controller on a Nissan, that had inline filters fitted to catch oil and water vapour before it hit the sensor.

[Tony C]

hi Rob,
Already ordered the 250kpa one,
But thanks for the link,
Would i benefit from using a filter on the map sensor line??? If so what size etc,
Parts should be here from vems today,

[Tony C]

popped out and bought a glue gun on the way home from work to be safe instead of using the silicone,
No parts here yet, fingers crossed tomorrow or Friday, can then get the map fitted and fingers crossed run the car up,

[rob@vems.co.uk]

In all honesty I don't know if it would help - yours is the first that I know of that has died.
If I could find the filter I'd take a photo of it.
Eitherway it might be an idea to blow out the vacuum tube with an airline or something - just in case its wet and the same thing happens again.
250KPA still gives you 1.5bar of boost to play with.

[Tony C]

parts arrived today and thought to myself,
im going to have a go myself at fitting this, (oh no i hear you all cry)

soldered the sensor to the board god its delicate work aint it 

powered it up and got a reading of 102.8kpa,
sucked and blew on the pipe and the gauge goes up and down 
quite pleased with myself now.
do i need to set the map sensor up at all?

[GintsK]

250KPa sensor: offset 10.0 range 249.5

[Tony C]

ta done that getting a reading of 100.5kpa now :-)

[rob@vems.co.uk]

I use the BBC weather webpage to find the air pressure in my area and make doubly sure of the calibration

[Tony C]

how do you know if the calibration is correct mate?
as the pressure reading near me is:
Pressure: 1024mb, rising

[dnb]

It sounds close enough to me for getting the car to start and run.  1024mb = 102.4kPa

When we meet up for tuning we can test the calibration - there are special tools for calibrating pressure sensors, but you can do as well with a boost/vac gauge.  It's not a case of simply changing the offset.

[Tony C]

will be a while before we meet up mate 
well for tunning anyways as the engine has an expensive  repair bill as in £1500,
having to sell off spares etc to fund the repair bill,

[dnb]

Owch!  What was the problem - thought it was nearly a new engine?

[Tony C]

it was a new engine, but we had the pistons changed to high comp (4.0lt HC ones fitted to raise the ratio up)
the guys that did them fooked the rod ends up by over heating and two pins came loose and went on a journey back and forth across the bore,

i will let the following pictures explain what we found

Cylinder 8:


Cylinder 4:


Side 1 of piston 4,


Side 2 of piston 4:


This what happened to piston 8 when we removed it,
the pin fellout on its own, 

[Sprocket]

I have heard this sort of thing happen before.

What about honing the little ends and running the pins fully floating? Use an aluminium bush in the ends of the pins so they won't score the bores in this manor. I have been running fully floating pins with Teflon bushes in the pins and so far so good. I have steel rods with a bronze little end, but I know a few of the high HP/lbft turbo Mini guys use the standard rods with the honed little ends. It makes rebuilds a little easier