1. Home
  2. Volvo automobiles
  3. Replacing the Air Mass Meter on a 940T

Replacing the Air Mass Meter on a 940T

I'm going through, bit by bit, replacing parts in order to try to fix whatever is causing my '93 940 turbo to threaten to stall. I only get the problem when the engine is up to temperature (never when cold) and it's not dropping off when cruising - it just threatens to stall if I've slowed down and the revs drop below 2000. They just keep on dropping.

Anyway, a couple of error codes came up when the mechanics checked, but all of the items that could be at fault are working to spec. So the only solution is to replace each part until I've replaced the one that's at fault - this could get very expensive!

This weekend, I'm replacing the AMM having picked one up second hand. Instructions for a dummy would be appreciated. Looking at it, there are two clamp-clips connecting rather fat hoses on each side of the AMM and an electrical connection on top. I'm assuming I just detach everything and substitute in the replacement.

Is this some kind of pressurised section? A sealed air hose/piece that I shouldn't play with?

Any help or advice gratefully received.

Reply to
tands
Loading thread data ...

I can't help you with the AMM but we have just gone through the same process with our 240e. Not the same model but similar symptoms - stalling when slowing down and when the engine is warm. After many part swaps it turned out to be the Fuel Pump Relay. Worth a look maybe?

Reply to
Beck

Thanks for the shout. I read a few people mentioning the fuel pump relay. It's one of the lists of bits that could be at fault. Being a very simple and cheap replacement, I'd hoped it would be. Alas, I changed it last weekend, but to no avail.

Reply to
tands

Also check the Throttle body which we did. Should not need replacing but could probably do with a good clean inside as gunk builds up in it and can cause similar problems. On our car it was attached next to the air mass meter so you should be able to find it easily. As for removing the AMM, just having a quick think back, I think all my Dad did to remove the AMM was to unclip it and remove the electrical connection then replace it. Not too big a job, just awkward as the clamp screws were in a hard to reach place.

Reply to
Beck

Just asked my Dad for the right info, if its the same connection type (although not the same model) just undo the jubilee clips and unscrew the bolt and it should come off cleanly.

Reply to
Beck

I just replaced the AMM in an '85 245 and will advise you as follows: test it, or have it tested with a VOM (volt-ohm-meter) before installing it.

The test is very easy and quick, you just touch the electrical leads to certain spots and look at the readings.

If the AMM is good, it will read within certain specifications; if it is out of spec, it is defective.

I had to check a couple used AMMs before I found one that wasn't bad.

Sounds like you're a newbie and haven't a clue what a VOM is or how to use it; if so, take the used VOM to a Volvo repair shop and ask them to test it.

The last thing you want to do is put in a bad AMM, thinking it is good, have the problem remain uncorrected, and keep trying to troubleshoot.

Reply to
zencraps

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.