air flow on intake filer cause rough idle...?
 

I noticed that when my cooling fans come on at idle, my motor would start running rough. i figured out that it was air from the fan blowing onto the intake filter that was the issue. why I don't understand.

i moved the intake tube out of the line of the fan blast and all is fine, but id like to understand what is going on. I know others have their filters in the fan blast and don't have this issue.

I found I did have some vacuum hoses run incorrectly at first but have them all sorted out now, and the issue is still there.


i made a video showing how a small fan on the intake causes a rough idle. perhaps that is normal?

https://youtu.be/9Ig1KhCTtLI

Re: air flow on intake filer cause rough idle...?
 

The additional air from the fan can "fool" the mass air flow sensor giving the ECM a false reading.

Re: air flow on intake filer cause rough idle...?
 

double post

Re: air flow on intake filer cause rough idle...?
 

is the ECU tuned for the different mass air sensor if not stock? that tube size is probably definatly not stock diameter.

when I bought the airraid universal maf card adapter, it was a little larger than OE. it would make it run like crap till the tables were tuned. this is a L83 motor which may be different than LS tuning?

look at the scanner and see what its showing..

Clint

Re: air flow on intake filer cause rough idle...?
 

Speartech did the harness, tuning, and it is their intake tube and sensor. I've spoken with them about it they are stumped as well. perhaps a faulty sensor? it will send a code for the sensor when I put a lot of air in with a bigger fan.

in its current position, everything runs fine.

Re: air flow on intake filer cause rough idle...?
 

absolutely unrelated, but thought I would share, I watched a youtube video while back on customizing something... wound up on a hose clamp mod / trick / hack or something or another.... dang it was stupid awesome.

https://imageshack.com/i/pncRFGM6j

(on the intake tube coupler)

harbor freight roll of heat shrink tube over the hose clamp, then shrunk down with the heat gun...
clint

Re: air flow on intake filer cause rough idle...?
 

Very cool on the hose clamp thing.