Technical JTD Power loss after large bump!

[Peat]

When driving at 60+ mph I hit a vertical ridge of about one and a half inches high running across the road (bridge parapet) immediately the engine lost power with little or no throttle response for about 500 yards. The power then came back in and I drove 5 miles to town and then across town with no further glitches.

However . . . .The next time I started up the power loss was back.

Up to about 2000rpm normal response and then flat to 5000. I checked to see if any vacuum pipes had been dislodged and all seemed OK. Having a spare MAF I exchanged them and LO & Behold . . engine power back to normal.

What I do not understand is what could possibly have caused the problem and wonder if the forum may have any thoughts on the matter.

 

[A3jeroen]

In my diesel days a MAF was a wire like in a bulb and it would measure how quick it would cool off (or how many power was needed to keep the same temperature).
Maybe when hot, the wire is prone to braking at a bump (I know H7 bulbs are extra sensitive).

Just my theory.

gr J

 

[Peat]

Thanks for that J.

On examination of the MAF I gently attempted to moved the element, although slightly soiled, looks to be solidly in place with no movement as does the diode(?).

I get the same reading on the diode both directions so if it is a diode it's failed!

After some searching I uncovered a Bosch PDF for MAFs and now know that the component I thought to be a diode is in fact a resister!