this is unrelated to the 9psi pulley i just put on. it started doing this saturday, and has gotten much worse since then. the car is a supercharged 2000 prelude.

essentially, if i let the revs fall to idle at any point in time besides starting the car up, it stalls. in order to drive the car i have to keep it revved at stop lights and use the other side of my foot for the brake, or use the e-brake. my a/f gauge reads slightly rich while this is happening; my fuel pressure gauge doesn't seem to show anything different than it used to!

i tried getting rid of all VAFC correction, which didn't make any difference. my JR EMS is not sending any terribly odd values to the ECU, since i can check the voltages on the VAFC.

any suggestions? my plugs are new, my pcv valve is new, i don't see any major vacuum leaks (although i haven't been getting a full 20" of vacuum very often lately.) could a really SMALL vacuum leak cause this behavior?

tia

 

I had the same issues when I had a bad IACV and IAT. Just a thought, and that was hell you went through on the pulley

 

hmm, i was screwing around in that area. maybe i fubar'd something.

 

I have some idle probs too, but it doesn't die, jsut idles funky and jerks from about 1500-2500 RPMs when driving.

I was reading on the Hondata site that the TPS should be set to .45V (and if not it could cause the problems I am having). I think I had read previously that it should be set between .50 and .55 V. I think when I set mine the lowest I could get it was .54 according to the AFC.

Do you think having it at that voltage could cause it to have problems?

 

Try taking of your IAC and spraying carb/injector cleaner through the screen. Take off your TB and look for any caked up carbon deposits around the butterfly and any orifices. Triple check for vacuum leaks. Then do an ECU reset.

 

Bad IAC and or TPS... I had similar problem.

Swapped out IAC wiht another one, same problem.. bought one at the dealer for 160.. and had same problem. Took it back and got it traded out for another one... installed and solved problem....

bad idle/low idle and car dying at a stoplight...

 

You can test the IACV. Pull the IACV off so you can see the little plunger inside. Lleave the car not running with the power on and ground the IACV wire from ECU. It should click and move when you do that.

You have so many bandaids, if your TPS doesn't register 0 to the ECU when your off the gas, the ECU doesn't think you're idling and wont start using the IACV to catch your RPMs.

 

Another test for the IAC is to take off the intake piping and put your finger over the hole at the 7'o'clock position. If the idle smooths out then there is something wrong w/ the IAC function.

 

thanks for all the suggestions people. i will try some of that.

my TPS signal is zero when i'm not on the gas, so nothing has changed there as far as i can tell. i did remove my intake a few days ago to clean it out, and may have someone screwed up something at the TB end when i put it back on. (although i don't think i removed the collar from the TB side).

also, i tightened my throttle cable a bit at the same time. could this have affected something? the helms mentions this as a possible cause of bad idle, but i'd think it would affect it in the other direction. the cable still has 1/4" of slack, at least.

 

i think i have the answer to your problem. you said you tightened your throttle cable right? well, the idle screw... might of come loose. when i tightened my idle screw, i didnt torque it enough so when it got hot it got loose, and the EXACT same problem happened... after starting the car, the idle would drop after revving and stall out. raise your idle a little bit and make sure the screw is really really tight. let me know if that helps!