S13 Runs rough then dies after aem cold air intake install
 

I just installed an AEM short ram air intake on my 93 240SX today. It ran perfect before the install and now it runs rough, the idle hovers, and steadily goes down until the engine dies. I was having problems with my car running very rough at startup due what what I believe was the catalytic converter being clogged. After beating the hell out of it with a hammer and laying on the throttle a few times it went away. Attched are two video clips. One is the engines characteristics while I lay on the gas pedal and the other is under the hood after the install. Sorry about the terrible quality and length of video, I only have a video recorder on my cellular phone. Any help would be great thanks.

YouTube - 0822091451

YouTube - 0822091452

You have a vacuum leak somewhere, or the MAF is not connected. There's nothing else you could do during an intake install to cause idle issues.

unless you you changed your intake filter to the element type that requires you to oil the filter such as k&n. the oil will gum up your maf sensor element and alter your maf reading to the ecu.

Im pretty positive my hoses are connected properly with no leaks and the MAF is definetely connected. It couldnt possibly be the previously clogged cat?

Ok I just checked out the plug for the MAF. It's a four pin female plug, but the far left prong is missing. Is it supposed to be missing to accept other model cars or did one of my prongs fall out and thats why my car is running so terrible? Can I just wire in another plug from another S13?

Exactly, the fourth pin is vacant. Viewing the harness connector from the wiring side with wires facing you, the vacant pin slot will be on the far right. From left to right the first wire is the MAF signal wire, the second is ground, and the third is 12 volt power. Also check this thread, guy has similar issue: #/f/tech-talk/269564...cks-power.html

When the MAF is unplugged the engine idles fine, but I can rev over 3k RPM. When I plugged the MAF back in the car died. Any ideas?

Bad MAF.

Maybe a coincidence, maybe you knocked it around a little and now it's dead.

Buy a new (used) one...they can be had for $20.

If you strike out locally, search for one on Car-Part.com--Used Auto Parts Market (junk yard search engine)

- Brian

I have a donor car at my parents house that runs fine, Ill pull the MAF off that and get back to everybody.Thanks, and I hope this works...kinda need my car to get to work tomorrow morning.

I figured out what the problem was. I had the MAF on basically upside down and backwards. The pins in the MAF can only read air flow one way, and that was the opposite way in which I had the MAF positioned. All is as it should be with the new short ram on, boy do I feel like a horses patoot!

Ah-hegh! Yea, you got to watch out for that. Theres an arrow on the MAF indicating air flow direction.

Theres one of those on my girlfriends vajayjay too, but that never stopped me from directing flow the other way.