MAF sensor

[_lithium_]

Where is the MAF located on a 1992 MX-3 GS 1.8L? Also, what is a good way of testing it?

[Pritchett]

Well I think the 92-93's were the same, If they are then its in between the airbox and ribbed Y pipe. Testing it..ummm I have no idea but im sure its on these forums somewhere.

[muttpower]

Doesnt have a MAF....K series are equiped with a VAF(vane air flow), and it's the cylinderical black plastic object with the wire connector in between the Throttle body and Air box.....as far as testing goes, if it wasnt working, then the engine would not run/sustain combustion

[_lithium_]

Ok, my main goal is to see if it is faulty, because my idles are surging (but only when clutch is down)

[mikeinaus]

Ok, my main goal is to see if it is faulty, because my idles are surging (but only when clutch is down)

doubt that would affect your idle problem. unplug your vaf and see how it runs. if its not workin properly the car wont even drive.

[Daninski]

Go to this link in the on-line manual for VAF inspection proceedures. http://www.mx-3.com/manuals/showimg.php ... F2-152.gif
JFYI it took me 10 minutes to find this and I seldon use the manuals. You can also clean the electrical element but you have to be very careful to only gently spray cleaner on the element.

[_lithium_]

Yeah I ended up finding it my Chilton manual. I am simply at a freakin' loss to knowing what the hell is causing this surging issue with my car. Everything I think it could be turns out nothing and some don't make sense. I don't understand why it'd simply go from 700RPM at idle (only when car is in gear at a stop and clutch is DOWN) then after it is put into the gear with the clutch still down, it goes up to 1,300RPM and sits until I hit the brake, then it will plummet to 700RPM and re-rev back up and then I hit the brake again and it falls again. But when driving, I can be driving going like 45mph and put the clutch down and put it in any gear (usually like 4th or 5th depending on speed) and hold the clutch down and the engine fast surges from 700RPM back up too 1,300 and repeats rather quick. WTF lol

[mikeinaus]

its normal for the 92/93 ecu to raise the idle when the car is in gear with the clutch in. my old 92 gs did this, my new 94gs does not. the fact the idle jumps like that probably has to do with a vacuum leak related to the braking system. try lowering your idle and see if it stops the surging. if it annoys you that much id suggest grabbing a 94/95 ecu and disty from the wreckers which should stop the car from raising the idle in gear.

[_lithium_]

Nah the idle raising isn't much of a bother, just the surging. Any clues to what hoses are vac for brake system?

[mikeinaus]

the only one i know of is that big one near the fill cap. try playing with your idle a bit and see if you can get it to stop. idle will roll if its too high or too low at any given time. lower it to 600ish then try up to 800ish and see if it does anything.

[MrMazda92]

600 RPM rise by putting it in gear? That's excessive... Mine goes up about 1-200 RPMs at the most, and I've never seen an example above 300.

I'd say the problems are linked, but I have no suggestions at this time other than that.

I should've kept it simple, don't assume the RPM rise in gear is normal. It'll help you troubleshoot.

[_lithium_]

I wasn't able to adjust the idle and make it stop (it kept doing the same thing). Someone mentioned to me though that if I unplug the IAC valve and turn the car on and the surging stops, it is the IAC going bad. I drove the car with it unplugged and the car drove like s--- (of course) but never did any surging. Is this true that it is bad then?

[Daninski]

You have to jump TEN and GRD in the diagnostics box then adjust idle to 650. When you remove the jumper it'll go to 700. If you don't jump those pins the ECU as much as possible will ignore your adjustment.

[mikeinaus]

I wasn't able to adjust the idle and make it stop (it kept doing the same thing). Someone mentioned to me though that if I unplug the IAC valve and turn the car on and the surging stops, it is the IAC going bad. I drove the car with it unplugged and the car drove like s--- (of course) but never did any surging. Is this true that it is bad then?

iac only affects the ecus ability to control the idle. as far as i know there should be no performance hit from unplugging it.

[_lithium_]

What do I need to use to jump the TEN and GND to put it in diagnostic mode? I looked in the manuals and can't find anything over this.


::EDIt:: found it, nvm