2002 Cavalier 2.4 TC, 5 speed. the only mods to the engine is a Pacesetter header and upper and lower mounts. stock intake.
when I first turn it on, the RPM's jump up to 2000, then slowly go down to 1500 where it "flutters" slowly.
I've pulled the stock intake off and examined it. I checked the seal around the top of the TB where the intake goes on. I don't see anything that would look like a vacuum leak. I took some TB cleaner and cleaned the plate and as much of the inside of the TB as possible. the only thing that looks out of the ordinary is a split in the air filter where it didn't seal right in the air box. might that cause a problem?
I did a search and a few people mentioned the IAT sensor. is this the sensor in the s-tube? how much do they cost?
thanks for any help.
Desert Tuners
“When you come across a big kettle of crazy, it’s best not to stir it.”
it's normal. it's not a problem. It is suppose to jump to 2000 when you start it then it goes down to 1500 then it goes down very slowly to 600rpm for the auto
When the engine is at operating temperature, it will not stay at 1500rpm.
Perfectly normal. Stop searching problem when there's none
Gilles
2.3 Ho
it does it even at normal operating temperature.
the car normally idles at around 800-900 rpm
Desert Tuners
“When you come across a big kettle of crazy, it’s best not to stir it.”
It's normal that it goes up then go down. At operating temperature it should not stick at 1500rpm for more than a few second.
Gilles
2.3 Ho
If you are that concerned, you can take an ohm-meter and measure the resistance in the IAC valve across A and B, then C and D, should be around 80 ohms. anything way off and the valve is bad. I cleaned out the TB where the valve goes in and it helped the idle.
Sam
Ban low-performance cars, not high-performance ones.
how about this ..is the engine light coming on? do you have a OBD2 scanner? see if there are any codes popping up if the engine is out of whack (range) then you'll have a code.. i'd start with that first before you start replacing unneed parts..
http://img86.imageshack.us/img86/4235/jim25ek.jpg
tried putting in another IAC and it still did the same thing. no CEL's at all. Eric (97cavieLS) helped me look at it tonight. disconnected the MAP sensor, car idled a little better and finally got a CEL after about 5-7 minutes. gonna go get the codes read in the morning. I'll post 'em up.
Desert Tuners
“When you come across a big kettle of crazy, it’s best not to stir it.”
of course you got a code, you disconneted the MAP sensor. You have a code for the MAP. Do I have to do a video of My Z to show you that your car is fine?
Gilles
2.3 Ho
look man... the car is acting different than it has been since I got it a YEAR ago. when I first started it, it would jump up to 1500 or so, and then go back down to 800-900. now, it jumps up to over 2000, and settles back down to around 1500.
and yes, I know that the reason I got the CEL is because the MAP sensor was disconnected.
if your car idles between 1500-2000 rpm after you first start it, and after it gets to normal operating temperature, there is something wrong.
Desert Tuners
“When you come across a big kettle of crazy, it’s best not to stir it.”
Mfk-223,
Jarett's car is
STAYING at 1500 - 2000 RPM when it
IS AT normal operating temps
INSTEAD OF being at the normal 8-900 RPM.
Now Jarett, You and I both know I'm far from being a competent gear-head to diagnose problems... However have you messed with your TB? On my Eco TB, there's a small Hex screw that the cable wheel rest on. I'm willing to bet there is one on your 2.4 TB, and I would assume that messing with that screw would effect the idle RPM's.
I'll have to take a look at it RJ. Eric fooled with it last night, and shook his head. I'm going to go get the codes read today or tomorrow, and see what comes up.
Eric's diagnosis was probably a leak somewhere off the intake mani. I'm going to buy a new gasket for it, and probably new rings for the injectors. but I'll definitely check out the throttle cables some more.
thanks bro.
Desert Tuners
“When you come across a big kettle of crazy, it’s best not to stir it.”
Listening very closely....i have the EXACT same problem. When I start my car it Jumps up to about 2000 then down to 1500 and stays there. I replaced the IAT sensor, that wasn't the problem. I cleaned the TB and all the plugs and that. Check everything no leaks. I really wish I could fix this too. I searched and searched and only came up with it maybe being the Throttle Position Sensor, not really sure which one that is. If someone can show me and Jarrett here maybe that could be the problem? all i know is i wanna get this fixed too. today!
Mark, from what Eric (97cavieLS) and I can figure out, is that there's a leak somehow off the intake mani or around the injectors. the car's pulling in more air through the leak, it throws the o2 sensor to too lean, adds more fuel and bam, higher idle.
the only thing we didn't try is the TPS. it's just weird that I never got a CEL until Eric pulled the MAP sensor.
I'll definitely keep you updated bro.
Desert Tuners
“When you come across a big kettle of crazy, it’s best not to stir it.”
Alright thanks man, keep me posted! I don't have a CEL either, so it seems we got the exact same problem on the exact same cars. haha. I just can't wait to figure out what it is. I'm gunna go look it over again.
cool. post up what you find. I can't do much right now as I'm at work. I woke up a little too late to get to Checker to have the codes read, but I do believe there's a guy here at work that has a code reader. if I'm able to use his reader, I'll post up what I find.
I'd really like to know what's wrong too. I know idling a little high isn't THAT bad, but it's just annoying.
Desert Tuners
“When you come across a big kettle of crazy, it’s best not to stir it.”
i got that same problem....i think its the map sensor its self....like the valve in it went bad and is letting to much air by....when u plug the hole it idles perffect rite at teh 6-800 where its supposed to be.....otherwise it idles at aroudn 13-1400 and i d k it sux....haha loud.....cant be good
Thanx Charles
Charles (the haha one) wrote:i got that same problem....i think its the map sensor its self....like the valve in it went bad and is letting to much air by....when u plug the hole it idles perffect rite at teh 6-800 where its supposed to be.....otherwise it idles at aroudn 13-1400 and i d k it sux....haha loud.....cant be good
I think you mean your IAC sensor. if I'm wrong, please correct me.
I got a code reader from a guy here at work, and unfortunately, the only thing that popped up was a P0107, the MAP sensor. this was expected, since it was unplugged last night. I'll keep doing some research to see what I can find out.
Desert Tuners
“When you come across a big kettle of crazy, it’s best not to stir it.”
check the vaccuum @ the fuel pressure regulator too, i have sorta the same problem, i got a new FPR and we will see if it fixes it.... i hope so $68 aint my idea of money well spent unless it fixes my problem. Stupid dealership, said "there is too much aftermarket done to your car, we dont know where to start" so now im tryin to figure it out again.
keep us updated bro. seems this is one hell of a problem.
Desert Tuners
“When you come across a big kettle of crazy, it’s best not to stir it.”
how about checking the cruise control line to make sure its not screwed in an extra thread etc.. and def. clean the throttle body
i unplugged all vacuum linesfrom the tb and blocked them
checked all the cables , none are holding it open
the tb blade is closed
when i blocked the IAC port the rag barely got sucked into the hole , where im used to a big suck
then it took a little while for it to drop rpm , tell i pulled the rag then it stalled
when i sprayed the injectors down and the intake , the motor seamed to stumble a little ,but it wasnt constant and wasnt a large stumble
when i unpluged the map the rpm droped to normal , and i tried other good know maps
his cav has about 100k on it
i really miss having the proper tools , idle air tools , and the TECH 2 , gotta miss the good stuff , LOL
he didnt have alot of time (small brain thoughts , LOL) and it was dark , so it was kinda hard to take time to pull and look over parts for any signs of problems
Brandon Schmidt wrote:how about checking the cruise control line to make sure its not screwed in an extra thread etc.. and def. clean the throttle body
I don't see the cruise control line doing it, as this problem just "appeared". and I did clean my throttle body. car runs better now... LOL... just idles high.
Desert Tuners
“When you come across a big kettle of crazy, it’s best not to stir it.”
*BUMP..............really would like to figure this out,.... any help.???.
Mark, I forgot that I got a spare intake mani with a gasket at home. if Eric has the time, I'm gonna see if he'll help me change it out this weekend and see if that helps.
figure out anything on your end?
Desert Tuners
“When you come across a big kettle of crazy, it’s best not to stir it.”
