13 replies to this topic

[Side-Swipe]

How exactly do those two work, how do you know if either is bad. I went to the FSM, couldnt find anything.

[Threedoor]

MAS and MAF are two different acronyms for the same part.  In the SQ's it is called a MAF (M mass A air F flow) sensor.  In the First and Second generation of DSM's (Eclipse, Talon, Laser) refered to as 1G and 2G for short the same part is called a MAS (M mass A airflow S sensor)

Some people switch over to a 1G MAS rather than cleaning / refurbishing their own stock MAF sensor.

What problems are you having?  I am NOT a SQ expert, but an actual question from you may lead the experts on the board in the right direction to be able to help you

Later,

Keith

<edit>  When I type Mass above and make the M bold with the rest of the word not bold the swear filter thinks I am typing a dirty word and changes it from Mass to Mtail.... sort of silly and I don't want to get in trouble trying to find a work around.... so I changed it to M mass even though it looks silly.

Edited by Threedoor, 19 January 2012 - 12:18 AM.

[Side-Swipe]

Well im asking about the second sensor that the 86's have.

[86starionIA]

Side-Swipe, on 19 January 2012 - 12:39 AM, said:

Well im asking about the second sensor that the 86's have.

the second sensor is a MAP sensor whis is manifold absolute pressure sensor

[Side-Swipe]

86starionIA, on 19 January 2012 - 02:38 AM, said:

the second sensor is a MAP sensor whis is manifold absolute pressure sensor

how do i know if it is working correctly

[Side-Swipe]

Anybody?

[StarquestRescue]

Side-Swipe, on 19 January 2012 - 03:40 AM, said:

how do i know if it is working correctly

Find the map sensor wire at the ecu plug. Pin a9 on a factory intercooled car, pin a17 on a car that was built with out the intercooler. Nick the wire with a knife and a connect the positive lead of a volt meter to it with a jumper wire. Ground the voltmeter negative lead. The voltage should vary with vacuum and boost changes. Spec says between .2 - 1.2 at idle and  be between 1.5-2.6 with the key on engine off. The voltage should go into the 4.x volts at full boost. It should also jump to 1.5-2.6 at idle every two minutes momentary.

[Side-Swipe]

StarquestRescue, on 21 January 2012 - 12:00 AM, said:

Find the map sensor wire at the ecu plug. Pin a9 on a factory intercooled car, pin a17 on a car that was built with out the intercooler. Nick the wire with a knife and a connect the positive lead of a volt meter to it with a jumper wire. Ground the voltmeter negative lead. The voltage should vary with vacuum and boost changes. Spec says between .2 - 1.2 at idle and  be between 1.5-2.6 with the key on engine off. The voltage should go into the 4.x volts at full boost. It should also jump to 1.5-2.6 at idle every two minutes momentary.

What would it do if it was not working correctly?

[Indiana]

You have the hoses on it?  Its on the firewall and it must run its reference hose through the solenoid valve and that valve has three ports.  One port is to the MAP, the other is to the throttlebody and the last is a reference hose that runs back over to the air filter can.  Have you tested the solenoid valve and made sure its not clogged or stuck?

The MAP, or as its called in the service manual, the "pressure sensor" has nothing to do with the air flow sensor.

Did I already ask about the air filter?

Edited by Indiana, 22 January 2012 - 12:44 AM.

[StarquestRescue]

Side-Swipe, on 21 January 2012 - 11:13 PM, said:

What would it do if it was not working correctly?

My car car ran pig rich and would fowl the plugs with in 5-10 minutes.

[Side-Swipe]

My car misfires consitently at around 5k and I think it runs rich, but it doesnt seem to foul plugs. Can I unplug it?

[Side-Swipe]

So I broke the nipple running to to the map sensor on the solenoid and it began running bad so I unPlugged the map and the misfire at 5k is gone

[Indiana]

Do you still have that BOV on there?  I hope not, if you do there's your problem.  You don't realize what that is doing to a MAF based fuel system.  At a higher rpm if your boost is gone that BOV can leak and it 100% does when you just slightly lift your foot then a massive volume of metered air is vented out and you can't understand why you are too rich?  You have no engine "braking" efect when in gear so your rpms do not drop as quickly and that lets more air escape than does in a manual transmission car.  At nearly any rpm level, on a slight decel you have more than enough vacuum to open that BOV and create all those issues.

[Side-Swipe]

Indiana, on 24 January 2012 - 05:08 AM, said:

Do you still have that BOV on there?  I hope not, if you do there's your problem.  You don't realize what that is doing to a MAF based fuel system.  At a higher rpm if your boost is gone that BOV can leak and it 100% does when you just slightly lift your foot then a massive volume of metered air is vented out and you can't understand why you are too rich?  You have no engine "braking" efect when in gear so your rpms do not drop as quickly and that lets more air escape than does in a manual transmission car.  At nearly any rpm level, on a slight decel you have more than enough vacuum to open that BOV and create all those issues.

I do have the BOV but the car had the misfire issues, before the BOV was placed there.