Thread: Would you say this MAF was faulty?

With my disco the stepper motor was the issue as far as idle was concerned,you could buy one of the chinese made MAF's for a little over a $100 and try it.I would take it to a tune shop,ultra tune etc and get them to run a system interigation and find out what is happening. Pat

Also check the throttle position sensor, with an analogue ohm meter, while its still warm.

Bruce.

OK i sorted it all out.A big thanks to Mike 90 RR.He pointed me in the right direction and now it all sorted Saved me a few hundred dollars as well.I checked the reading off the AFM and the TPS.And they were well out.My initial TPS reading was .24 volts and ive got it on .33 volts.Which is where it should be i think.I forgot to read the AFM reading but it is now perfectly adjusted to about 1.3.
It was a pretty simple job to do and didnt take me long at all.All i needed to use was a multimeter.So if you think your AFM is stuffed try this first.It might save you alot of money in the long run It idles nicely now with no hunting or stalling.And thanks BMac for the reply as well.

Originally Posted by SPROVER

OK i sorted it all out.A big thanks to Mike 90 RR.He pointed me in the right direction and now it all sorted Saved me a few hundred dollars as well.I checked the reading off the AFM and the TPS.And they were well out.My initial TPS reading was .24 volts and ive got it on .33 volts.Which is where it should be i think.I forgot to read the AFM reading but it is now perfectly adjusted to about 1.3.
It was a pretty simple job to do and didnt take me long at all.All i needed to use was a multimeter.So if you think your AFM is stuffed try this first.It might save you alot of money in the long run It idles nicely now with no hunting or stalling.And thanks BMac for the reply as well.

Voltage reading on a MAF is an approximate fix and will get you out of trouble, to set it correctly you need to stick an analyser in the tail pipe and adjust it to specs.

Originally Posted by It'sNotWorthComplaining!

Voltage reading on a MAF is an approximate fix and will get you out of trouble, to set it correctly you need to stick an analyser in the tail pipe and adjust it to specs.

The specs are only for ADR's. With catalytic engines, this adjusts the MAF correctly for the oxygen sensors to make sure they are getting the correct information and for this setup is a reasonably critical function.

For non-cat engines, the "spec" is to set it to 1200ppm and 1% CO2, purely for emissions.
A non cat engine will respond to both TPS and MAF adjustments as a "tweaking" measure and have quite dramatic results in just about all cases.

By no means is it an "approximate fix" but a mandatory check at least once a year in a major service.

With a lot of these engines getting tired now, adjusting to specs will never happen and can send the engine into fits of hunting and running rough due to loss of compression, poor ignition etc etc.

Cheers

Andrew.

Originally Posted by LOVEMYRANGIE

A non cat engine will respond to both TPS and MAF adjustments as a "tweaking" measure and have quite dramatic results in just about all cases.

And a big thanks to LOVEMYRANGIE & PHILLIPA for getting my beast to behave itself

Since i have adjusted it i have had no problems at all. Ive done a couple of hundred kays and she idles better,doesnt hunt in the rev range and most of all it hasnt stalled.

Read this with interest as my 94 classic has similar symptoms. I'd really appreciate any info on how the AFM is adjusted, what the setting should be and where it is measured, have done the TPS adjustment before on my old car but never adjusted this AFM. Also can you remind me which wires to measure the TPS setting from?
Have you noticed any improvement in economy with this adjustment? my car seems to be running very rich and guzzling petrol.
Thanks
Pete