Air Intake Device?

[Garry2009]

Hi All...new member here:

I just bought a 1999 Explorer yesterday. It's a 4.0 L OHV, not a Sport or XLT, and I don't see XLS anywhere...only says Explorer MP on the registration.

On top of the air intake duct, just to the right of the filter housing, is some kind of solid state device; relay, sensor, or whatever. If I plug this thing in, the car won't start. If I start the car and then plug it in, it kills the engine instantly. The obvious thought is "bad device, replace it". But shotgunning can be expensive and not necessarily productive. Does anyone know what this thing is, and why it's killing the engine?

Thanks in advance for any help.

 

[Dan Whitaker]

That is your MAF (mas air flow) sensor.

Try cleaning it with MAF cleaner. You can buy the cleaner at any parts store.
Do not use anything but the MAF cleaner.

If the sensor gets dirty it will cause all kinds of issues.

 

[Garry2009]

MAF Sensor...

Hi Dan, thanks for the reply:

There's a salvage yard just down the road from me...the guy sold me a sensor & housing this morning for $40 (he doesn't bother taking the sensor itself off that short housing). I popped it on and the problem disappeared. HOLY SMOKES what a difference that thing makes in engine performance, huh? I thought I might see some difference if it was the problem, but I surely wasn't prepared to see THAT much difference!

Anyway...he says those things are a common problem with Explorers, but luckily he has a bunch of them on the shelf. So I know where to go if it starts acting up again

Thanks again,
Garry

 

[colintrax]

You should just clean it. More power, better idle, and where cheaper than buying another one.

 

[Sbyrne97]

its a very good tune up procedure to check your MAF especially on older cars they get all sorts of stuff on them and can get dirty. Check your plugs and wires as well

also make sure the filter housing and tube is secured and properly clamped...If the old MAF got that load of crap on it...odds are the housing or tube may be a culprit also look for holes you never know what there may be...

 

[Joe Dirt]

Agreed- no need to keep buying MAF's. They rarely crap out, they are usually just dirty... And yes, being dirty can create that much of a problem for you...

 

[01EXP5.0]

Don't know if anyone else has ever heard of this but my buddy at the stealership told me oiled aftermarked filters will coat the maf and cause it to malfunction.

 

[Joe Dirt]

He's correct- they will... After having several tuned SHO's and a couple of Mustangs, I noticed no real difference in the K&N vs. paper filter, so from having to clean the MAF's on them from the oil blowoff onto the MAF filament, I nixed them altogether. I know some people swear by them, but dyno numbers never proved (at least on my cars) that they did anything worth the $

 

[ShadyGrady]

A dry type-clean it yourself-permanent-air filter is now available from AFE, AEM, and a few other brand names. Sold from popular outfits such as E-BAY, Auto-Zone, Advance Auto, Pep boys, and a few others. You blow/vacuum/wash them the same way you do the K & N but use any mild soap/water mix and gentle water stream from the garden hose to rinse...I use dish detergent/water mixed in a bucket of water, then wash my car with the left overs! LOL!! I am so cheap! I agree with cleaning the MAF...it is a good way to fix a simple problem...I use electrical parts cleaner, and air dry it before use. Works for me.

 

[01EXP5.0]

That's good to know. I am currently running a cold-air intake kit I picked up from Explorer Express. The filter needs to be cleaned but I think I will swap it for the dry type. Thanks