peterbanks

I recently installed the Comptech CAI, once finished with the install, I pulled the back up fuse to reset the computer. The car had the typical symptom of computer reset, almost stalling when coming to a stop. My question is how long before the computer re-learns the new setup? Its been at least a week since I pulled the fuse and I am still getting the occasional RPM's dropping below normal when coming to a stop. Or is this just a characteristic of CAI's? Thanks

trich1687

Check your vacuum lines one may be routed wrong. Do you have a CEL ? CAI should not be doing what you describe. Use the search and you will fine threads with pics of the proper vacuum line setup.

peterbanks

No CEL, vac lines are installed correctly. What I'm describing is an intermittent stumble of the RPM's when coming to a stop. For example: Driving down the road coming to a stop light, the RPM's are coming down from 5K and instead of stopping at 800 they drop to 300 and then jump back to 800 and remain steady. I'd say this happens maybe one out of every five stops. It's in no way as bad as when the computer was first reset. After the reset the car almost stalled twice when coming to a stop, then was back to normal. This is just the RPM's dropping more than I remember.

Big Ben

I agree. The S2000's ECU is the most sensative I have ever owned. When I pull the back up fuse for any reason, it always takes about a day or a long drive(15 minutes or longer at different rpm's) to have the ECU "learn" what has happened.

darkknight1999

Check your MAP sensor. Tap it with the back of a screwdriver. My car has does this same thing for a while now. I have the Comptech CAI as well and the MAP sensor has a harder time dealing with the extra incoming air.

I've heard that if you replace the stock S2K MAP with one from a early 90's Civic MAP sensor the problem stops. I just can't remember what year it is.

ricosuave

i've had the same problem.

from what i hear, it's related to the air filter. it causes the car to run rich. take a look at your exhaust pipe and in a while it'll turn black. i've switched to another air filter and removed the box. fewer stalls.

peterbanks

So do you think the stock computer can actually negate the positive effects of mods? Like the rich condition that was described earlier, I would imagine that running rich is not optimal for performance. So as you add a mod the computer adjusts the positive effects of that mod to keep the car as close to the stock condition as possible? Does this make any sense?

darkknight1999

It can but only to a point, then you get the results, ie: HP or TQ gains...... I would check your map sensor I'll bet its dusty

xviper

Something else is going on here. Pulling the back up fuse alone will not cause any resultant issues. I've pulled the fuse on my car and on another car several times with absolutely no negative effects. It may simply be coincidental that your idle is acting up and "may" not have anything to do with the CAI installation, UNLESS you have "created" an issue by accident while doing the installation (even though your vacuum lines may be OK). BTW, sometimes, incorrect vacuum line routing can take several driving cycles before you get a CEL, especially if you mounted the check valve BACKWARDS.
Another thought: When you pull the back up ECU fuse, it is possible to accidentally short it when replacing it. A blown backup fuse will give you the identical symptoms as the idle issue just described.