I just installed a K&N CAI and a Motordyne 5/16ths Iso spacer. When I start the engine and let it idle, it is inconsistent and idles very low (700-600 RPMs). A little more information that might help out an outside diagnosis is that when I took the plenum upper manifold off, the existing gasket bent where it connected to the intake manifold collector cover. So, I took the outer part of the gasket off. I had advise that is won't make a difference because the spacer is the new gasket essentially. I can't help but think that might be my problem. Any ideas would be awesome. Thanks

 

Reset ecu after install? Clean the maf sensor as well

 

I haven't reset the ecu, but I have cleaned the throttle body as well as the mass airflow sensor. I am going to put another gasket on tomorrow so the next step would be to reset the ecu. You recommend getting that done for me, or is it fairly easy to do on my own? I've never done it before but I have access to a computer to hook it up to.

 

Any more thoughts anyone?

 

sounds like you have an air leak in spacer. Happens alot. Did you torque the bolts to spec? I would re-torque the bolts.

 

reset the ecu and throttle body position. Almost guaranteed that is your problem.

 

I don't have an inch-pound torque wrench I only have a 30-150 foot-pound one so that'll do me no good. I just tightened down the bolts with a regular hand driver. it says to tighten them to 100 inch-pounds which, as far as I can tell is about as tight as I can get it by hand. I'll find an inch-pound torque wrench to make it exact, thanks.

I'll reset the ecu tomorrow and see if thats the problem but what is the deal with the throttle body position? how do I reset that?

 

is there any other way to reset my ecu without having to do that pedal dance? I've had a hell of a time getting the timing right and it hasn't worked, at least with the last ten times I've tried it.

 

^disconnect the battery for a few hours. Should reset.

 

Same problem, same intake, no spacer. Ecu reset via pedal sequence worked temporarily but started to bounce again, cleaning amf and disconnecting battery for a while worked. Careful cleaning the amf though do not hold it upside down so any fluid runs into it and use brake cleaner that works fine if you have it. Also careful what you clean the throttle body with because you can remove the layer of film the manuf applies and give you problems. Good luck keep posted.

 

Also, as much as it drives you insane, if you dont time the sequence exactly correct after the light has flashed the whole process could be useless and nothing had reset with no real way to tell unless the problem had suddenly stopped. Using a watch with a second hand really does make a huge difference in the difficulty in timing it i tried a good 5 or 6 times before i got frustrated and finally grabbed a watch and got it right. Dont know if any of this helps but these are some of the things i ran into.

 

So, I got the new upper intake manifold gasket on, put the 5/16ths spacer back on, cleaned the inside of the plenum, and tightened the bolts that hold the plenum on a little tighter than 100 inch-pounds. It still idles at about 650RPMs but it is slightly more steady. I talked to a mechanic and he said that the ecu will have to adjust to the differences in airflow that the engine is getting and to give it a week of monitoring it and driving it as much as possible and it should self adjust. If it doesn't I'll plug it in to an obdII. I'll keep you guys posted, thanks for all the help!

 

ok... I put the stock intake back in and it worked fine so that rules out the plenum spacer. I'm just going to draw the conclusion that K&N products don't work well in Infinitis, at least their CAIs. I'm going to look at other brands and find out what other people use that works. Thanks for all the help guiding the newb through.

 

Grab a can of brake parts cleaner....


turn on the car, and spray a bit on all the parts you touched ( like the seals and intake hoses)

see if the car accelerates, if so you left that area loose.

 

I had the same problems when I first put on my JWT pop-charger and z-tube. I left the battery unplugged overnight when I did the install, but still, once my car was fully warmed up and I came to a stop, the idle RPMs would drop wayyy down, almost to the point of stalling. Once I did the ECU and throttle body position reset (using the on/off ignition and pedal reset), my car ran smooth as stock.
*It takes about 1000 miles for the ECU to adjust on its own*

If you are sure the ECU/throttle body position reset worked, and you still had this problem, my guess would be that you might have had a leak somewhere. So after you re-installed the plenum spacer, you still had the CAI on, and it was still giving you problems, and then once you removed the CAI, it was fine? Are you sure everything on the CAI was sealed properly (MAF to CAI, clamps tight, etc)?