CLIFF NOTES AT THE BOTTOM

its an 03 6 speed, and for the past three months, i haven't driven it. been very busy and most of the time i have been using the truck for work and whatever, and also to give the CL a rest from all the miles i put on her and that she needs new tires and brakes.

anyway, decided to start her up today and take her out. all seems well for the first 15 seconds after start up, then the RPM climb to about 2250. i think ok, hasn't been started in like 30 days, gas is old(and almost empty), no problem. then the RPM's drop to 1000 and keep surging to 2000, takes about 1-2 seconds to go from one to another. tried letting it rest 5 - 10 -15 minutes, same results
my question is obviously why is it doing this? seems like when the RPM drop back to 1000, there is a sound like a blow off valve(sounds cool but i'm NA!).

now i want to drive the car reallly reallly and its not working right. this happened to my civic years and years ago, but i can't remember how i remedied it? I know its not something serious, but i want to fix it thanks in advance!!
keep in mind i've never had any problems before-oil is filled.....

CLIFF NOTES
-didn't drive car for 3 months, but started from time to time.
-started today, its surging from 1000- 2000 RPM"s and sounds like a BOV when dropping to 1000 RPM's. tried letting it rest-didn't help
-never had anyother problems, all fluids good but low on gas-need your guys help(that doesn't sound right?)

 

I've read about this before and I can't remember what it was. I know I've heard of it happening though. Try searching "idle" maybe?

 

Check your vacuum lines. I'd bet one of those are kinked, clogged or fallen off.

 

Happened to my 98 3.0 CL. It's a sensor of some sort that has gone bad. Maybe the oxygen sensor. Your mechanic will probably recognize the symtoms right off.

 

when that happened on the old cars it usually was the cold idle valve but the cl does not have one, try this, plug IAC valve passage with your finger in the slot inside the throttle body and start the engine does it stop doing it if yes then you know you have a problem somewhere in the IAC circuit. then i would test from there, it might not be the valve itself or the wiring, or the computer might be telling it to do that and if it is that why would it tell it to do that? that's what you have to find out.

 

thanks for responding guys. well i went to the gas station, filled up and the next mile afterwards, the pulsing stopped, but then the check engine light came on. car is running great, no pulsing, hesitation, vtec is engaging...so now i'm gonna have to go to auto zone to get the CEL codes or i might just disconnect the battery and see what happens from there.
also the brakes were making a weird noise, even when not applied, but it stopped-figured it was from rust/dirt building up over the 3 months.

 

what temp was it outside when you started the car and it acted weird, and how old was the gas, i'm betting your haveing the old winter fuel on a warm day problem. i'm betting the codes you will pull will be one of these if not more than one p0300, p0301 p0302 p0303 p0304 p0305 p0306

 

Civicking, again, here we go. He is not having a missfire problem, nor is it a heatsoak problem due to winter fuels.

It is the Idle Air Control Valve. Period. This is extremely common.

 

i've seen it before and seen happen to others. damned faulty parts like the IACV or motor mounts.

 

I'd get the codes read before you disconnect the battery. At least you'd know what they were first.

A code scanner is cheap. You should get one. I have one, & it's been usefull not just on my car, but others as well.

 

if it was an IAC problem then why was it a ton better after filling it up. i have never fixed a IAC problem by filling up the tank, if that was true that's how i would fix all the cars. And also fuel does not heat soak, do you know what heat soak is? Fuel can evaporate in the fuel line if there is not enough pressure and its really hot, that will cause vapor lock. And in the winter fuel to summer fuel thing, what happens is that the winter fuel is more volatile so that the car will run when its -10 outside, the problem with that is that when its really warm you will get the air bubbles in the fuel expanding causing a rough idle, and the car will see misfire codes. also what do you do for a living to say what i say is not true, because i fix cars everyday for my job and right now I'm studying to be an automotive engineer.

 

ok to answer a few questions, it was about 50-55 and sunny yesterday. when i filled up i needed about 16 gallons so i was pretty empty.

i haven't started her today, so idon't know if everything is how it was when i first started her yesterday, or how it was when the night was over.

i'm gonna try to get a code scanner to see what the codes are, cause i'm surious to know, and it seems like some of you are too!!

 

You don't have to be an engineer to know that your CL-S's problem is not fuel related, m&b6speed. It's the IACV, just like it is for the rest of the people with erratic idling like you described. This is very common.. I've had numerous Honda cars do the same thing.

 

It should be a faulty throttle body. it happened to my car. my car jumped between 1-2 thousand rpm also.

 

03CoupeV6: Spot on!
Civicking: Stay in school. (Bless his trying little heart)

 

Probably just needs to clean the IAC valve, maybe not replace? If it has a tendency to stick like mine did (this causes the surging), it was always worse (and a first indication?) after sitting for a few days. Also cold made it worse, as the goop inside is gooeyest. I got mine replaced under dealer goodwill, as I had mentioned it on a work order while it (01 CL-S) was still under warranty.

 

if you guys seem to know so much how come its a lot better after he filled it up, that has no effect on the IAC system, and to the guy who told me to stay in school, one word, i bet i have more knowledge about cars in my little pinky them you have in your whole body. i want to know what codes got pulled out, first and foremost.

 

OK, you can be smarter than me. All wippersnappers like you just want the codes. Gimme the codes! How can I survive without my codes?
It's coincidental that it seemed as if the gas station had any effect, but it was only a red herring. The car simply warmed up, and the goop in the IAC valve softened, and the car got better because the IAC valve loosened itself up. Gas station or not. Need more proof? You would probably need to travel 3-4 miles before any of the gas you just pumped got burned. That's not how I read the info. Am I missing something?

 

I agree seeing the codes would be useful to know why the CEL came on.

 

i want to see the codes just to see what the ecu thins is wrong, but if you read higher in the thread i told him how to test, really all it takes is one finger you know the same you stick in your........wait i'm getting off the point. next gas does not layer itself in the tank, what the hell, if lets say he had 10% old stuff and filled up that 10% its now mixed with 90% new fresh gas that means that its basically so diluted that it will not matter anymore. And the fuel lines don't hold gallons of gas, the second that car is started new gas is already in the line, i would bet it does not take more than 10-15 seconds before its all flushed out of the line.

 

well before i could get around to either getting a code reader, or having the codes read at a shop, the engine light turned off and never came back on. i don't know if the codes will be stored in the CPU, but i probably won't get it read if ithey are, i just been way too busy and it aint slowing up any time soon!

 

they should be stored in the computer, under history codes.