My idle fluctuates when I hold it between 2K- 3K RPMS. D16Y8 (OBD II), T3, 450cc DSM's, Walbro 255 intank, and VAFC hack- 42, 40, 40, 38, 36, 35, 35. Here's a list of everything I've tried...

2) IAC is good
3) Ignition timing is good
4) Blade in the throttle body is good (cleaned the TB out too)
5) Fuel is good, 35 psi to the rail (lowered it from 40psi thinking it may of been rich, still fluctuating )
6) Bled the coolant and filled it
7) Couldn't find a vacuum leak

I have a permenant secondary o2 code, no cat, could that be doing it? I know these threads are a dime a dozen. I found a ton when I searched, but I'm about to lose it. PLEASE HELP!!!!! TIA


[Modified by Tony Starks, 4:30 PM 3/6/2003]

 

to elimnate the seconday o2 code from comming back remove the o2 from the cat and hang it somewhere under the car keep it away from any thing plastic cause the sensor is heated and will melt stuff and then plug up to o2 hole with a junk o2 or a plug please respond with what was the prblem when you fix it

 

does it fluctauate at idle?

i ahd the same problem,turned out to be a wrong TB gasket,h22 throttle body and tried to use a type r gasket.

 

did you reset the ecu after you made these changes? is your idle set correctly?

 

At idle is the only time it fluctuates. Its doesn't act up during driving. Sorry, should of said that earlier.

I won't throw a code for not having a secondary o2 sensor? The ecu is going to see that there isn't a sensor there and throw it.

 

ECU was reset. Idle is set correctly.

 

any..........more...........ideas????

 

at what exact point did this start?

 

Like two weeks ago. It just started doing it. It didn't start right after I installed something. Idled like crap since I put the VAFC in though. Cured the rough idle yesterday by decreasing my fuel pressure to the rail. Too rich.

 

could it be your ficv (fast idle control valve..) or a bad evap system? check for vacuum leaks in your evap.

 

I'll check the FICV. Dunno where that it is off the top of my head, but my helms will tell me. Someone told me to check under my TB for that "plate with two screws." My TB didn't have one.

 

check for vaccum leaks broke, intake manifold gasket, or anything that plugs up to the intake mani....take some brake cleaner/carb cleaner and spray around to see where the leak is, depending on what you use, the engine will DIE or REV up where the leak is.

 

Tried it. No leaks.

 

Must......get.......more......suggestions......

A very reliable source from H-T told me he lived with this problem the entire time he had his mini-me. Anybody else just living with it? I'm close to giving up too.

 

This is what my problem was. My car would idel from 1k to 3k rpm and drive me crazy, everyone thought i was reving on them.

 

herer is an answer to your problem but no way to fix it i have the same one.....
i put a header and cat back on my car with a pipe in there instead of a cat back now mine is doing as you discribe idles really low almost dies or dies everytime. but my car is running rich. a dx has 2 o2 sensors, and ex has 1. The dx has one before cat. and 1 after. you need the dummy o2 sensor..which i have no clue where to get one. or dril a hole and mount the second o2 sensor so both read that will make the check engine light go off and that will also make the car idle strait again...exuast shops can help you out most for free. jsut ask.

 

i got the same problem!!!!i need help on this but no 1 seem to kno the answer i guess its somewhat normal...does it feel like your car is lobing? as if you had cams in it on idle?

 

i changed the uhhhhh....... **** what's it called. Under the throttle body, that's what i changed and it stopped. Idles fine now.

 

i got one maybe its a vacuum leak in the injector area!

 

yeah, I'm working on getting an o2 simulator from Importparts.com right now. $49.99. Hopefully it helps. It'll get rid of my CEL anyway. I'm gonna try the FICV tomorrow night. Hope thats it. If not, I'm screwed.

 

that's it, the fast idle valve, once you get that, this should stop. I'll put money on it.

 

Nope. Dremeled out some integra seals and they fit the dsm's perfectly. The injectors went right into the manifold. No leaks. I can't remember who wrote up that injector seal trick, but thanks again.

 

fast idle valve whats it do?

 

so only at idle it fluctuates? by how much?

 

It only fluctuates at idle, it fluctuates about 250 to 500 RPM's inbetween 2K and 3K. Thats it. Thats the only bad spot in the RPM range and only at idle!!!! To answer the post a couple above, yeah it lobs a little bit at idle. Still a little to rich, I think.