1990 240SX Burned Air Filter

[dferraro]

To All: The Air Filter on my 1990 240SX is burning up after about 4-5K miles. The metal grill on the filter is so charred that it disintegrates. It is the lower part of the grill that is charred. The paper part of the filter is very wet, sometimes with a gas smell. I have done all of the standard replacements, spark plugs, rotor, fuel filter, pcv, etc. Does anyone have any suggestions? Thanks

[MastaYu]

any pics

[dferraro]

Hi MastaYu,

I can take some over the weekend and post them next week.

Thanks

[MastaYu]

nice,sounds like a very akward situation. kind of like my clutch pedal trying to start my car except no fire here

[S13Joe]

Dude, your about like 20 minutes away from me, if you need any help let me know.

[dferraro]

Hi DirtyGhettoKids,

Thanks for the offer. I'll let you know.

[S13Joe]

No problem man, but for now you should take some pictures of it. Have you noticed any decrease in gas mileage?

[dferraro]

I've been getting very poor mileage, about 10-12 mpg which I've attributed to my short commute (4 mi) to the train station. Thanks

[i240sx]

unhooking the hose to your air box....see what happen next...

[Dunky Kong]

This one needs pics to solve

[dferraro]

To All: I didn't realize that I needed a web site to host the pictures. I hope that the pictures are viewable. Thanks

[dferraro]

To All:

Try this http://home.att.net/~dferraro/index.html

If this doesn't work, it will have to wait until I can get more time to play with posting the pictures. Too much actual work to do at work today. Thanks

[TroubleBound]

Heh damn that is pretty charred. I like how you have the tow truck company sticker right on your air box haha that doesn't look good. Thats real wierd though i cant imagine how its getting burned inside of the box...super hot NY air? Heh sorry for the useless lack of diag just wanted to comment on your sticker.

[OutToWinPAHC]

Could be combustion during the intake stroke. Possibly caused by a leaking injector?

Any backfiring by chance?

[dferraro]

No backfiring.

Just to add to the pictures. When I took the filter out, it was very wet (water?). It didn't have any smell. If you look at the picture showing the paper side you can see the difference in the color of the paper. Thanks

[3rd_240]

jeez... what does your MAF sensor look like??? even though it may not have anything to do with why its doing that i bet it looks pretty bad too.

[rico05]

Backfiring thru the intake. Check your timing and your dizzy. My buddy's car also did this with a clogged catalytic converter.

[sebazztard]

Backfiring thru the intake. Check your timing and your dizzy. My buddy's car also did this with a clogged catalytic converter.

this is all it could be lol. pretty crazy tho, ive never seen anything like that under a hood unless the whole car caught on fire. def have a timing issue, and prob leaky injector. i would most definatly not drive this car untill you get it corrected. take out the stock air intake and see what it looks/smells like through there.

[dferraro]

The timing was ok when I checked it last year (Sept or Oct). I had replaced the dist, rotor, plugs, air filter at the same time. I can recheck the timing just to be sure. I've had the problem for a few years now. I only just found this forum. How would I check to see if one of the injectors is leaking? When I check the timing I can also take a look at the MAF that had also been requested. Thanks

[rico05]

I have a buddy who's #1 injector was leaking so bad it was spitting fuel out of the exhaust gasket and he never had this issue. I still vote timing. And did you only check electronic timing or did you check mechanical? Like cam gear vs. crank pulley.

[dferraro]

I'n not sure what you mean by "check electronic timing or did you check mechanical". I used a timing light.

[dferraro]

To All: From what I could find out it seems that my problem is caused by the AIV or PAIR Valve. See this link for more info zerothread/254273 Thanks

[ZOMG.SR20]

you have a bad cat the cat is clogged up with so much "stuff" that its backing up through to the header into the EGR and the PAIR valve caue in your air filter to combust

Buy test pipe and remove cat problem solved also ypu can get rid of the PAIR valve if need be also

[S13Joe]

you have a bad cat the cat is clogged up with so much "stuff" that its backing up through to the header into the EGR and the PAIR valve caue in your air filter to combust

Buy test pipe and remove cat problem solved also ypu can get rid of the PAIR valve if need be also

I hope your car is already inspected then. Or you can just take a trip upstate.

[dferraro]

To All: Just an update... Last night I disconnected the hose from the air filter case that connects to the resonator. I covered the open end of the hose with a foam filter from a lawn mower. This morning, the car seemed to have no power under 30 mph. It seemed to take forever to get above 30. Once over 30, the car seemed normal. I will provide another update tomorrow after I see how it performs on the way home tonight. I've had the idle problem described in the tutorial but only on the way home when the outside temp was warmer then 40 degs or so. The tach would usually oscillate bet 100 & 1500rpm when I was sitting at a light. If it was a long light, the car would stall; but it would start right up. If it is ok tonight, I will try to take the AIV apart over the weekend to clean it. Thanks

[ZOMG.SR20]

its your CAT.

[SullivanRacing06]

cats clogged, forcing a crap ton of of exhaust gas to be forced thru your egr valve and in to your air box

[dferraro]

To all: Is there any way to test if it is the CAT(short of removing it) that is causing the problem? My symptoms seem to match what was written in the tutorial about the AIV. I am trying to fix it as cheaply as possible as the car is mostly used just to go to the train. Thanks

[rico05]

Smells like horrible. Glowing cat. And all other issues that you are experiencing.

And FYI: You checked your electronic timing with the timing light. That means when the #1 cylinder fires the plug. It is an electronic timing of the spark distrubution. But, as we know, that is only part of the equation. You also have valves that open and close. This is the mechanical timing that is timed by the relation of the cam's rotation phase to the crank's rotation phase. You really need to download a factory service manual and do some research into the Otto or 4 cycle engine's inner workings.

[dferraro]

I don't have any type of smell (rotten eggs) in or under the car. When it is running everthing under the car looks normal, nothing leaking or hot. Thanks