Grand AM :: 1999 / 3.4 - Erratic Idle On Start-up
Starts rough but clears up after about a minute, I'm assuming the IAC is sticking. Whats the proper procedure for disconnecting and removing the cleaning and re-installing?
View 4 RepliesPassat (B5) :: High / Erratic Idle When Raining
The other day when it was raining out my car started idling below 1,000RPM/running rough. I was thinking it might be the coils, so I changed those, cleaned out my TB (Throttle Body), did a TB alignment (with VAG-COM) and now my car is idling at 1,200RPM and jumping up to about 1,600-1,800RPM, like I'm constantly revving it. I even swapped out my whole TB from my A4 and it still does it! If I disconnect the throttle position sensor it seems to idle normal.
View 2 RepliesSanta Fe (CM - 2007-12) :: Engine Light And Erratic Idle
My wife was complaining of the ESC light came on and off. Rough idle. Also has a check engine lite.
View 23 RepliesFord - Mustang :: 1994 - Erratic Idle And Stalling
I have a 94 Cobra Mustang with a 5.0. For the past few months it has had an erratic Idle and stalls when trying to idle. I've had a number of suggestions on how to fix it and nothings seems to work. I checked for vacuum leaks, changed PCV, new plugs, new IAC valve, tested ICM and throttle TPS and even adjusted idle. Still no luck.
View 3 RepliesTouareg :: Engine Light Came - Idle Erratic After Car Started?
I know its a shot in the dark but my engine light came on the other night. Its a 07 v8 with 25k mileage. i started it up idled fine for 30 secs, then the idle started to get erratic up and own for 15 secs leveled off and the car ran fine. I drove for 10 minutes turned the car off for a couple of hours came ack started her up and engine light came on no rough idle or anything.
View 8 RepliesFord - Explorersport :: 1999 - Erratic RPMs When Idle And Rev When Braking
Here is a YouTube video showing my erratic RPMs while idling in park, then pressing and releasing the brakes and gas to show what happens each time: [URL] ....
I just bought a 99 Explorer Sport. The history I know is that the truck has 200k+ miles on it, with the engine replaced. Replacement engine has 90k on it.
Was told the fuel pump, and serpentine belt (I think, he said "main belt") were replaced in the last few months.
The car was driving fine on the test drive and for the first few days of owning it. Then a clicking sound started form under the hood while driving.
I first noted the clicking while at a red light, and when I accelerated it stopped. Over the last week it has increased in frequency every day and now is almost constant.
This evening I was coming to a stop with my foot off the gas and when I hit the brakes the RPM went up, and car lurched forward before stopping gently. This kept happening so I drove home and took the above video. Video taken shows the RPMs jumping up when in park and going form idle to idle with brake depressed. when I rev the gas and let go, the RPMs fall, hang for a couple seconds, and then fall back to ~1000. The captions are very accurate, they show exactly when the brake or gas was pressed and when they were let go.
My obvious question would be WHAT IS CAUSING THIS? Also, ARE THE CLICKING AND THE RPMs RELATED? Finally, SHOULD I AVOID DRIVING IT? I need to drive it a few times through the next few days and I can't really avoid it unless it will mean serious damage.
Santa FE SM (2001-06) :: Erratic Idle - Revs Up And Down From 1200 To 2600 RPM
Daughter's 2001 Santa Fe Delta V-6 2.5 engine, needed lower ball joints. Replaced the entire lower arms as more cost effective & actually a bit less work, for me anyway.
So While under it, see oil dripping down back of engine. Decided to replace valve cover gaskets. So I start to disconnect all the involved connectors, brackets etc to pull the Upper air intake to get to the rear cover.
While moving around, find most of the hoses & vac lines baked brittle and dried out and loose even tho clamped, so I replace all of those, plus the PCV valve., & the upper & lower radiator hoses as well. I only removed the upper 1/2 of the intake. I change out the cover gaskets, reassemble every thing, reconnect all the connectors. I noticed that some of the connectors could apparently be switched to other sensors, but since all the lines seemed so backed solid, they actually retained their positions to go back onto the proper sensors.(at least I hoped so & it seemed that way).
Anyway, every thing back together & tightened up, so I start it up & the idle is at about 3000 to 3400 RPMs. WTF? So I pop the throttle a couple of times by hand and finally it drops down to normal, then just as suddenly, it begins SEARCHING for lack of a better word, and starts racing upto 2600 rpm then drops to 1200 then up again then down again.
No check engine light or other idiot lights on. So I shut it down & check all the connections and hoses, nothing disconnected or left off or loose. I start it again, and it immediately begins running high & low searching for the idle again.
I shut it down again, and put the MacPro scanner on it and NO codes either set or pending. I next check the Haynes Manual I have for it, & the closest thing I can find to my problem says: Engine Lopes while idling or idles erratically 1) Vac leak 2) Leaking EGR 3)Air filt clogged 4) Fuel pump not delivering enough fuel 5) Leaking head gasket 6) Timing belt/sprockets worn 7) Camshaft lobes worn
By process of elimination, not #'s 2) According to service manual, there is no EGR valve on the 2.7, and I couldn't find one either, #3) Air Filter is new & clean, #4) ran fine before I worked on it & with the engine revving up to 34 or 3600 rpms, getting plenty of fuel, #5) Have had many head gasket problems over the years on many vehicles, never anything like this, and again, it ran fine until I worked on it #6 & 7) Doesn't seem to me to be a belt sprocket or cam shaft problem, as none of that was touched & again, it ran fine until I worked on it. This kind of narrows it down to #1, for me, but this is not like any vacuum leak I have ever come across in 45 years of auto repair. I have found & fixed many stumbling idles due to minor leaks but never had anything like this.
I next called a friend who owned an automotive machine shop & who I used to do work for, and now runs a highway dept garage for a municipality who has been a certified mechanic for many years, told him all the above & the only thing he could come up with was a MAJOR vacuum leak, like possibly the upper plenum gasket rolled up or got torn some how when I replaced the plenum and he suggested that I try a smoke test.
Scratching my head, I go back to the car, & break out my home made smoke machine that I use to successfully pinpoint leaks in emissions systems. I ran it for quite awhile, and found some light smoke leaking from somewhere down around the head, but due to the construction of the engine & no way to get the light to shine under the plenum, could only guess that he may have been right & that there may be a large leak down at the lower intake manifold to head gasket. Needless to say, I removed the upper plenum again, & this time also the manifold to heads, and the gaskets looked like they may possibly have leaked slightly between the ports, & quite possibly somewhere around the number 6 cylinder. So I cleaned the surfaces & am putting on the new gaskets that came in the set with the upper plenum to manifold gasket set.
My questions after relating all of this:
1) The 2 gaskets between the manifold & the cylinder heads have a blue stripe around all 3 cylinder port holes (appears to be some kind of sealant or factory applied silicone bead) & there are no markings of any kind anywhere on the gaskets, so do the blue stripes face DOWN to the heads or UP to the bottom of the intake manifold ?
2) Regardless of which way these stripes face, should I use any kind of high temp sealant around the port holes in addition to the gaskets, or just install them dry ?
3) Can the Idle Air Control on the Throttle Body Fail & affect the idle like the problem I am having, but NOT set a computer code ?
4) Can the Throttle Position Sensor affect the idle like this and NOT set a computer code?
5) I also found an electronic valve between the Air Intake & firewall, it is labeled PCV and has an OEM part number after that, I believe this to be the Purge Control Valve, which connects the TB to a plastic line which I believe runs down to the emissions canister under the vehicles front seats. Am I correct in thinking that even if this part had failed, it would have NOTHING to do with my erratic Idle problem, but would throw an emissions computer code?
Elantra XD (2001-06) :: 2002 - Erratic Idle And Ran Rough At 1200 Rpm
I just picked up an 02 Hyundai elantra manual trans that needed a transmission. ran fine before I replaced transmission but after putting it all back together the car now how has an erratic idle. it will rev from 2-4000 rpms. I tried spraying for vacuum leaks idle didn't pick up any higher. replaced tps and iac and didn't make a difference. the only thing that did make any difference is unplugging map sensor. dropped idle to about 1200 rpm but ran rough. could this affect the idle.
View 1 RepliesFord F-150 - 1997-2003 :: Erratic Idle When Get Off The Freeway And Stop
I have an 01 f150 4.6 4x4 automatic with 90,000 miles. I have an erratic idle but it only happens when I am on the freeway well actually when I get off the freeway and stop. the idle will fluctuate between 750and then drop to 400 then back and forth til I get moving again. I replaced the IACV because it was doing the weird humming and vibrating the intake tube. The humming is gone but still idles funny as stated above.
View 4 RepliesElantra XD (2001-06) :: P0519 Idle Erratic / RPMs Constantly High
My friend was having trouble with her 2001 elantra. Her idle was erratic and her RPMs were constantly high. we checked every where for a vacuum leak but could not find one in any of the lines. We went on to switch out the idle air control valve, the throttle position sensor, and even cleaned out her throttle body. we threw up our hands and sent it to a shop. Come to find out there WAS a vacuum leak. apparently in the air idle control valve sensor there is a gasket that seemed to be missing. I of course didn't think about replacing a gasket when I replaced the sensor because I never saw one there.
View 1 RepliesPrius (2004-09) :: Check Engine Light Code - Erratic Idle
It came on 2 months ago, took it to dealer, code said "erratic idle", it idled fine, smooth as it always has been, dealer turned of lite, said let him know if it comes on again.
View 2 RepliesFord - Explorer :: 2008 V6 - Erratic / Jumping Idle While At Higher RPMs
My wifes 2008 Eddie Bauer Explorer V-6 recently started having an erratic idle and we've started noticing it while at higher RPM's. Its almost as if there is a cylinder that misfires but no engine light is coming on. The car stumbles like it is going to start to die, then the idle jumps up and smooths out. A little while later it does the same thing. The car has I think 74,000 miles on it and has never had the plugs or wires changed. I change out the fuel filter roughly every 24,000 miles and did it recently in the spring. Any places where I should start looking? Could a misfire not trigger the check engine light?
View 3 RepliesAccord :: 98 / 2.3L - Erratic Idle Speeds / Engine Can Barely Stay Running When Warm Up
98 Honda Accord with 2.3L has 354,000 miles on it and up until recently ran like it was still new. Have developed erratic idle speeds. When it is cold it idles around 1100-1200 rpm. When the radiator fans are on or the A/C compressor is on it runs around 800-900 rpm. These are normal speeds and great. However, when the engine is warm/hot, in PARK, radiator fans are off, and A/C compressor kicks off, the idle speed drops to what appears to be about a rough idling 500 rpm's and the engine can barely stay running. I've attempted to look for the obvious. I own the Honda Shop Service manual if there is a particular component or most likely suspect area I should start at.
View 6 RepliesFord Aerostar :: Erratic Idle - Air / Fuel Ratio Is Too Lean Or Rich For PCM To Correct
97 shortie. 3.0 245,000 miles. I've already cleaned the throttle body and the idle air control valve. Throttle position sensor reads 5 volts, good ground, and a smooth voltage increase from idle to wide open throttle and back down. Which of these codes is most likely to cause erratic idle? Mostly in the morning.
P0340 Camshaft position sensor.
P1443 Evaporative purge flow sensor.
P0401 Insufficient EGR flow.
P0171 Air/fuel ratio is too lean or rich for PCM to correct.
I doubt it's number 1, and number 4 seems too general to be any use. I'm leaning toward number 3. Seems I read somewhere that the tube from the exhaust gets plugged up. This started when I disconnected a plug from the blue air bag box to get rid of that beeping. Coincidence?
Elantra XD (2001-06) :: 2005 - Slight Erratic Idle / Check Engine Light And Codes
I just purchased a 2005 elantra with 133k on it and she runs fine other than a slight erratic idle. And by slight I mean it will jump about 50-100 rpm idling and every blue moon it will jump up to 250 rpm sitting there. After idling for a while my CEL came on with the following codes.
P0507 idle air control rpm high
P0506 idle air control rpm low
P0170 fuel trim malfunction bank 1
P0121 throttle position sensor
What could be causing this? I took the iac off and cleaned it with maf cleaner but it didn't work.
Ford F-150 (2004-2008) :: Vacuum Leak Causing Erratic Idle - Codes PO171 / 174?
I tugged on the little hose on the back pass. side of the engine,(5.4),...
and I could hear the vacuum leak that is apparently causing the erratic idle, and PO171 & PO174 to come up.
I know this hose is hooked to the Charge motion Control Valve on the back of the manifold,..I can't imagine what it does, as it terminates with some kind of plug or check valve??? Haynes say's to remove the entire manifold to get to the CMCV.
I can see it with a mirror,. I am thinking maybe long needle nose from Harbor freight,...bend the tip short,..maybe be able to change it out?????
Ford Escape / Hybrid :: 2001- Erratic Idle Speed Due To Vacuum Elbow Collapsing?
I've read quite a bit in various threads about the large vacuum elbow collapsing, causing erratic idle speeds. My 2001 3.0 had that issue int he past. I shoved a 1/2" copper 45 degree elbow inside of the rubber elbow, and the problem was solved... until a few days ago.
We're now getting into the hot part of summer here. I've notice the same symptoms are beginning to return, once the engine compartment gets hot. My question is... is the large vacuum line a "hard line" all the rest of the way to the engine, or are there other places along it's length that can also collapse under vacuum?
Ford Ranger / B-Series :: Erratic Idle / Sporadic Miss / 3 Cylinders On Right Bank Dropping In And Out
Its a 1994 with 4.0, automatic, 4x4. Running fine, parked it, a week later I'm getting a bad but sporadic miss that according to the stealership is the 3 cylinders on the right bank dropping in and out. Driving down the road you can feel them drop out and when they come back its a kick in the pants like a turbo kicked in.
Shop says wires are good, plugs are good, and then lost me when they started talking around in circles and not making much sense.
What could make 3 cylinders all on the same side of the engine drop in and out? This wasn't anything that slowly came on. Fine one day, crap the next. The only thing I did prior to was replace the IAC because it was idling high, it was cruddy inside, and it looked like it was original. It was running fine after that till this issue popped up out of nowhere.
Mileage was claimed to be 178k but I'm beginning to suspect it's probably 278k.
Ford 7.3L Power Stroke (1999-2003) :: Flutter At Cruising Speeds And Erratic Idle
I've been having problems with hesitation and a flutter at cruising speeds as well as erratic idle. I have a 2000 F-250 SD with 497K Miles. I was having poor starts during florida winter ( had to plug in a couple times) Had no oil coming out of #2 inject and #8 buzz was weak. Flutter was there and was the original reason I started digging. Right now the only code Im throwing with my chip turned off is a P0470. I cleaned the tube and the sensor but its still throwing.
I have recently replaced all Injectors, Glow Plugs, Valve Cover Gaskets & Harnesses, CPS, Fuel Pump, ICP was replaced before new plug no oil showing.
Mods: 6637 Air Cleaner, TS-6 Chip
Truck has mad power now no problem starting. Its really starting to frustrate me Ford dealer wont troubleshoot unless I remove the chip. I feel like it should be something simple because on the throttle it will set you back in your seat cruising at 70+ no flutter ..... but slow down to 50 55 in traffic and let off the throttle when you start to ease back into it 1500 - 1800 "buck buck buck" if I monitor ICP pressure I see a fluctuation in psi of about 200 -300 psi (1400 to 1200 or 1000 to 800) . If I throttle harder it will stop or let off the throttle. I can feel it do it sometimes before the TC locks so I dont think its a TC issue. I even tested with OD off and I can recreate. The magic area appears to be 1500 - 2000 rpm....