Installed K&n Cone Filter And Adapter, Now Runs Like Crap
 

88 gxl, car ran fine before, all was installed corrrect, installed a conicical filter, and maf adapter, now there is a high rpm miss i think, power seemed great till like 6000 rpm, then went flat.

any input would be great

is there less cold air now that vent duct over radiator is not hooked up?

more air flow, probably hotter air...

is the AFM level? the flapper should move parallel with the ground so that gravity won't pull the door open or closed (even if just a little) so they say on the forums

pretty sure its level

Of course the car wont make power after 6k rpm's..I would double check all your connect's and make sure you have everything connected right.

just because the air was warmer it wouldn't cause the car to run shitty.

it normally makes power past the buzzer,lol
it started breakin up at full throttle, third gear, like 5500 rpm and up

check for leaks?

i visually did, i will with propellant tomorrof

Someone told me a while back that your car will run lean after installing intake and exhaust. You should try some TII injectors for secondaries or maybe a new fuel pump. I had the same issue but in your case it could be anything, like a bad O2 sensor perhaps.

exhaust maybe.....open filter will probably cause your car to run richer due to less air going into the engine.......more airflow of hotter air = less air mass overall

get it dynoed asap...intake and exhaust mods can make the car leaner or richer...and it would probably help if the filter was not exposed to hot air...hotter intake air = less power

should i put the airbox back in, and do a drop in filter?

Good Idea!!!!

get a new fuel filter

Just on that, has anyone done a write up for putting the K&N into the stock airbox? I had a look at it and it didnt look all that possible. Any help would be great!

Uh, no. I am running Stock Injectors and Fuel pump each with over 300k miles with Street Headers, Street Port and 2.5" Exhasut 6 ports wired open, no airbox with open filter like K&N. My air fuel on a Dyno are dead on and dyno ~160hp to the wheels.

i have not replaced fuel filter yet, might help, car was on a 1/8th tank, would that kill me?

but car always ran rich, and ran strong before a stupid cone filter




............i was talking about the k&n thats a factory square filter, thats called a drop in, instead of the cone filter...........

There's no reason to upgrade the fuel system, and there's no reason to spend $100 an hour to book a dyno on a car where there is no way to tune the fuel curve.

A simple troubleshooting step would be to remove the K&N filter and see if the car improves. If so, then the issue is with the filter.

What was done with the air pump line that would normally be connected to the airbox?

Seriously i ran the K&N filter on my 87 GXL for about 2 years with no problem's and telling this guy to dyno his car and to upgrade his injector's is just ridiculous!

check your grounds, lol

Yes, the intake air will be a little warmer now, but that shouldn't cause the problem that you describe. Something else is wrong, most likely something that you accidentally disconnected when removing the stock air box, although it could be something not related to your recent work.

Slap that person. Our cars have an airflow meter, so no matter how you change the airflow to the engine, it still measures it. The same applies if the air is heated or cooled.

TII injectors will make the engine run like crap unless it has a properly tuned aftermarket fuel computer to control them.

1. Buy K&N air filter 33-2017.
2. Unscrew the screws on the stock air box.
3. Remove the cover of the stock air box.
4. Remove the old air filter.
5. Install the K&N air filter.
6. Replace the cover of the stock air box.
7. Install the air box screws.
8. Nominate Evil Aviator for a Nobel Peace Prize for writing this complicated and innovative process.

i left the hose off to the air pump, since i have no cats and air pump is disconnected for now.

i made 2 brackets, leveled the maf out, full tank of gas, and made a air scoop to the filter based off the oem scoop over the radiator.

we will see what happens

Evil, I think he meant using a cone filter in the stock box. It's been a while since I've looked at the stock box, so I dunno if that would work or not.

But you get my nomination!



Double check all of your hoses + wires for lose connections.

just got back, ran strong, no miss/flatness, very responsive

makes a sloppy air sucking noise at low rpm though.....i can only hear it with windows open
this is my first mass air car, so that may be it, may be the air flyin past the vane

Mine doesn't sound sloppy. When I'm on the throttle a bit, I can hear the 'bark' of the intake.