Thread: I keep killing airflow meters

Originally Posted by streaky

Any ideas what kills air flow meters?

It's normally LPG powered cars, when they backfire... but if you don't have LPG?

It might be some sort of electrical short?

Correct...no LPG.

The injector rail was removed and new injectors fitted etc. Wouldn't a short curcuit kill the AFM electronics immediatly and not after a test run??

Thanks.

S.

Originally Posted by streaky

I recently had some mapping work done on the Discovery. It has a 3AM airflow meter, new plugs and injectors were fitted at the same time.

Within 180km the power dissapeared and I was in limp home mode @ 2000rpm.
I changed the AFM for a another 3AM and got going again. Within 30km the AFM was shot and I was back int limp home mode @ 2000rpm.
Yesterday I wasn't able to source a 3AM so fitted a 5AM instead.
The car drove like a charm for the first 30km and then the AFM died and I had to drive home at 40-50km per hour at max 2000rpm.

This means I've killed three AFM's within the spate of a single tank of petrol.

Any ideas what kills air flow meters?

Could it be that the Mapping work done is causing the problems?

Originally Posted by streaky

Wouldn't a short curcuit kill the AFM electronics immediatly and not after a test run??

Yes, you're probably right.


Is the Discovery a series 1 with 300Tdi and electronic controlled injection?

We didn't get the electronic controlled 300Tdi in Oz, so I doubt many people here would have any experience with re-mapping it, but I'm sure someone must have some ideas.

EDIT: Whoops...lost my mind here...diesel has no AFM!

Originally Posted by nice1guv

Yes, you're probably right.


Is the Discovery a series 1 with 300Tdi and electronic controlled injection?

We didn't get the electronic controlled 300Tdi in Oz, so I doubt many people here would have any experience with re-mapping it, but I'm sure someone must have some ideas.

He mentioned new plugs and a tank of petrol, so looks like a V8.....

may sound silly, but could it possibly be dodgy contact surfaces within the AFM plug? works fine when its first plugs in then shifts a tiny bit and creates problems?

i had that problem with the RB30 in my VL commodore years ago, the crank angle sensor used to give me trouble, changed the plug with a new one, and it was fine after that

Do you know that the MAFs are dead? or is it just that the ECU thinks it is dead. Limp home mode could also be triggered by a TPS giving an out of range signal, or a temp sensor giving an out of range signal(I think) Check the "dead" MAFs on another car, and if it is OK , then the wiring may be suspect. There is a 14CUX diagnostic in the manual. How did someone do remapping on a 14CUX in Dubai?? Does it have a piggyback? If the ECU has been disturbed have you checked that the ECU plug is on properly? Regards Philip A

As jazzaD1 wrote, it could well be dodgy contacts... It is Lucus, y'know...

I had an issue where mine would go mega-rich to the point it wouldn't even idle. Tried lots of things, with limited success. Then tried giving the pins a very slight twist with needle-nose pliers and both connections a squirt with Contact Cleaner. Note "very slight" twist ! The twist increases the pre-load between the connections giving a better connection. Worth a try... and free.

Mine hasn't missed a beat since... and it's been years...