TD4 MAF sensor

Alan C said:

Ah, lefty drive? You'd need to look through the right hand front wheel arch and get someone to rev the engine, unless you have very long arms! The mechanism can't be seen from the left hand side.

Alan C

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Alan C said:

My engine is still faulty :-(

I installed a brand new LR MAF the other day, also the Pierberg MAF with the Synergy unit, and of course the original MAF, all give the same result. LR dealer has suggested the new MAF they suppled may be faulty, but I doubt it, though they have got another on order for me to try. I've also replaced the fuel rail presure sensor, this is now a modified part and comes with a replacement loom as the original plug tended to allow water in and corrode the contacts. Mine were bright and clean, though I will change it, this involves removing the inlet manifold for access, so also have gaskets on order. One sensor I haven't changed is the inlet manifold presure sensor, this tells the ECU how much turbo boost presure is available, could be duff, but not so much that the ECU sees wrong data from it? Anyway, it's the last sensor to change! The crank and cam position sensors would be pointless to change, engine wouldn't start or run if these were faulty. After I've tried all the above, that only leaves the wiring and ECU, which a specialist ECU repairer I spoke to doubts is faulty. He seems to think that when the MAF is disconnected and the ECU is running in default mode, the inlet presure sensor may be ignored, so also have this on order. £500+ in replaced parts so far......

You can check very easily if your boost solenoid is working, lie on the floor next to the O/S/F wheel with the drivers door open, while looking through the wheel arch at the turbo reach under the door and push the throttle, you should see the mechanism on the turbo move, it's a round cylinder with a rod from it's center, this should move outwards slightly and return when the throttle is released.

Alan C

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Blue407 said:

Hi

Did you discover the source of the problem in the end? and what symptoms were you getting?

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Alan C said:

The symptons were a severe lack of power, could hardly acheive 30 MPH, with no engine malfunction light and no error codes in the ECU. Turned out to be the inlet manifold presure sensor. It was clogged with a thick tar like substance which had coated most of the inside of the inlet manifold. I suspect this had come through the EGR valve as unburnt and semi-burnt diesel. I cleaned out the valve and all was fine, but as I had one on order I replaced it. I think due to it being pretty much blocked, it was reporting low inlet pressure, but just within specs, so far too much air, not enough fuel, but not so far out the ECU thought there was anything amiss.

Alan

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Alan C said:

If anyone needs to know, the easiest way to replace the MAF sensor is to remove the 2 screws securing the actual sensor to the duct. Land Rover sell it complete with the duct, a Rover Ron Pierberg MAF is the sensor only. Thing is, these screws are a bit strange, they are 5 point security star, not the usual 6 point star, I've actually found they're called security star plus, and the size you'll need is TS25, on a 1/4 drive socket is best as a screwdriver will be too long to get into the limited space. Franklin tools seems to be the only supplier of these, found a set in a motor factors, but also available on Ebay:
Franklin Tamperproof Torx Plus 5 Point Star Bits (TSP1) on eBay, also, Hand Tools, Garage Equipment Tools, Cars, Parts Vehicles (end time 10-Mar-09 18:30:43 GMT)

Hope this helps!

Alan C

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