Air Mass Meter Questions

That's no excuse. A car should start equally well whether it is raining or sunny.

Failure to start in wet weather is pretty typically of disintegrating ignition wires and/or cracked distributor crack. Other electrical insulation failures can cause problems too.

From your description I am not convinced that the AMM needed to be replaced. However, could be that you had two things go wrong with the car. Hope this helps!

Hi Michael,

"No Start Fault" can certainly mean that the car will not start. I experienced this recently with my '93 245 Classic. I pulled out the AMM plug, pushed it in and pulled it out ten times. (A Volvo technician had recommended this procedure to me earlier for just such a problem.) It worked. The engine turned over and started immediately.

BTW, an excellent maintenance routine is to repeat the above but with the application of contact cleaner to the contacts beforehand. To finish the job coat the contacts with dielectric grease.

Good Luck. Andy I.

: > > I had a starting problem with a 1995 Volvo 940. Once started the car : > > would run fine. The problem was intermittent at first. On one : > > occasion it was very difficult to start but did start. A few weeks : > > later the car would not start but after sitting for several hours it : > > did start. A mechanic replaced the Air Mass Meter. When I got the : > > car back it would not start but it had been raining. : >

: > That's no excuse. A car should start equally well whether it is raining : > or sunny. : >

: > > Over a four day period it would not start but at the end of the : > > fourth day (one day with no rain) the car did start but after a great : > > deal of effort. I gave the car back to my daughter and that day : > > again it would not start. : > > I took the car to a different mechanic and they found a wire to the : > > coil that was bad. I have the wire and the connector to the coil is : > > falling apart. After replacing the wire the car has started every : > > time. They also replace the fuel pump relay but said this was : > > probably not the problem. : >

: > Failure to start in wet weather is pretty typically of disintegrating : > ignition wires and/or cracked distributor crack. Other electrical : > insulation failures can cause problems too. : >

: > > What I would like to know is: : > >

: > > 1. What are the symptoms of a bad Air Mass Meter? : >

: >

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> AMMCalibration : >

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: > From your description I am not convinced that the AMM needed to be : > replaced. However, could be that you had two things go wrong with the : > car. Hope this helps! :

Usually the motor will start and die, if you unplug the AMM it will start and run, but you will get poor throttle response, substantially increased fuel consumption and poor emissions.

Normally the car will still start just fine, it just won't keep running. Sometimes it will not start at all.

Normally starts out intermittant, then becomes continuous, but it can go from running fine to not running at all in an instant depending on how the AMM fails.

Yes, whey they fail, they make the engine run poorly all around.

Not the ones I've had fail, in theory it could happen though.

Certainly not, I find the codes are right about half the time, other times it's the wiring or a vacuum leak.

Your symptoms sound exactly like a bad high tension lead, which is what the second mechanic replaced. The AMM was 99% likely just fine.

>

I solved a similar problem years ago with a TBI Reliant with a 2.2L engine. It would not start in wet, foggy weather. The Chrysler dealer replaced one computer and it ran fine - until the next time it was foggy and raining. Then they wanted to charge for another "scan" and part as the second scan said the 2nd computer (part) was faulty.

I went to Radio Shack and bought a spray can of contact cleaner and cleaned all computer "plugs" as well as every plug that i could find on the wiring harness - including the one to the distributor. I put grease on the plugs going into the "computer".

That was the LAST time I had a no-start problem with the vehicle (rain or shine) until I totalled the vehicle ;-)

Ken, Canada

To those components, Ken, I can recommend the same treatment for those notoriously troublesome fuses in the 240 series, 'tho' in that case a preliminary fine-wire brushing to remove corrosion deposits is a good idea. Better still, scrap all these fuses with the grey-colored zinc-alloy ends and substitute copper/brass ended types (available at outlets catering to VW, not Volvo sad to say..........). Follow up with the contact cleaner/ dielectric grease routine. Same for the contacts in the fusebox.

Happy Motoring. Andy I.

: > BTW, an excellent maintenance routine is to repeat the above but with the : > application of contact cleaner to the contacts beforehand. To finish the : > job coat the contacts with dielectric grease. : : I solved a similar problem years ago with a TBI Reliant with a 2.2L : engine. It would not start in wet, foggy weather. The Chrysler dealer : replaced one computer and it ran fine - until the next time it was foggy : and raining. Then they wanted to charge for another "scan" and part as : the second scan said the 2nd computer (part) was faulty. : : I went to Radio Shack and bought a spray can of contact cleaner and : cleaned all computer "plugs" as well as every plug that i could find on : the wiring harness - including the one to the distributor. I put grease : on the plugs going into the "computer". : : That was the LAST time I had a no-start problem with the vehicle (rain : or shine) until I totalled the vehicle ;-) : : Ken, Canada