Suburban :: 2001 - High Idle Delayed Shifting
Jun 10, 2015
My 2001 Suburban, 1500, 5.3L, 2WD with 164k miles, has a problem with high idle and delayed shifting. The high idle occurs when the vehicle has been driven around for awhile. When I start it up, even when already warm, idle is normal (~600 rpm). After some time, however, it idles at 900 to 1100 rpm. The delayed shifting happens right away--almost like I have the tow/haul mode turned on.
I have cleaned out the idle air port, cleaned the MAF sensor, replaced the idle air control valve, replaced the PCV valve, replaced the engine temperature sensor, and unhooked the battery to reset things. It still idles high.
I first noticed this a few weeks ago when the battery died. After I put in the new battery, the idle was very low. So I cleaned out the idle air port and valve. Then it was high. I drove it around for a few days like that and then started replacing stuff, to no avail--still high. I also cleaned around the throttle plate.
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After I start my Lesabre when cold, after about 15 minutes or so it starts idling high, usually about 1500 , but sometimes it's as high as 2300 while stopped at a light. And a few times it has been 3-4000 rpm after putting it into PARK. After it starts idling high it starts shifting late. If you shut the engine off and immediately restart it, it usually starts idling fine again temporarily. Engine has normal power and runs smooth and idles smooth. It has also randomly died a couple times while driving at 30-40mph but then immediately restarted as if there was no problem.
It has a P0121 code which is "throttle position sensor switch A circuit range/performance problem". It also has a P0420, "Catalyst System Efficiency Below Threshold (Bank 1) ", which I'm not sure is related to the issue because the check engine light had been on a long time before the idling/shifting issue started happening. Like in the neighborhood of a year and a half before the current issue, but it ran fine the entire time and got 30+mpg on the highway.
First thing I did to troubleshoot was to test the TPS and it seemed ok. Voltmeter readings were .4v with throttle closed and seemed to advance smoothly up to 4.4v at WOT. But, I tested it before the engine was hot and I don't have a Oscope. I then used some carb cleaner and shot it around the injectors and a few vacuum inlets to check for vacuum leaks, to no effect. Engine runs quiet and I don't really hear any vac leaks.
Next, I cleaned the idle air control valve which was pretty dang dirty, but that didn't seem to resolve the issue, although it may have had a slight effect because the issue seems to come and go some while driving now, but I'm not totally sure. I also tested the connector at the IAC and had voltage on all 4 pins between .4v - 11.4v approximately.
Lastly, I got the engine to reproduce the problem and then pulled and then reconnected these sensors one at a time while the engine was idling high:
MAF Sensor
TPS
IAC
Intake Air Temp Sensor
This didn't have the slightest effect on the engine... I'm thinking it might actually be the TPS or IAC but I don't want to just start replacing stuff without knowing damn near certain it's going to resolve the issue. Could a vehicle speed sensor cause this? How I should proceed from here? :?
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Brother in law has the above truck with shifting problem. On a cold start, pulling out of the driveway, it will get to about 3-4000 rpm and will slam into gear. Sometimes its worse than others, but is consistant. Once it warms up, the problem goes away for the most part.
I've researched a little online and have found a few people mention the 1-2 shift accumulator (servo...?) and was wondering if any of you have ran into this or have replaced one on the A4LD.
And if you have, which servo is the 1-2 shift? I think there are 6 of the little suckers in there. Anyway, all i've done so far is fluid and filter. Old fluid looked/smelled fine.
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I have a 94 C2500 suburban with a TBI 454BB. Obviously, I'm not concerned with fuel mileage, but I am currently getting about 4 miles to the gallon because the idle is stuck at 1800RPM. Normal idle for my model according to the index book is 750RPM. it's usually pretty close to that when operating normally (+/-25RPM). 3 days ago I did my biannual throttle body cleaning. Took it completely off replaced the gasket cleaned the throttle body and put it all back together. This is when the problem started... It now idles at 2300 RPM, it threw the code for bad idle air control valve, and I figured I probably got the plug wet when cleaning the throttle body, so I went ahead and ate the 60 bucks and replaced it.
Went through the reset process for the ECM to learn the new one and it the idle has come down to 1800RPM, it also literally DUMPING fuel through the injectors into the top of the throttle body. While I don't believe it is actually running rich, it seems more like the idle is trying to compensate for the excess fuel that is being dumped into the top end. Now, Before I go any further I want someone else's input. "I" think it is a also a bad throttle position sensor that probably got wet when cleaning the TB. But I am worried it could also be the PCM has finally gone out, although this is probably not likely because the entire ignition is run by this and if it was bad, it would stand to reason that it wouldn't run at all. Or it could be a bad vacuums control module. I have checked all my vacuum lines and do not have any leaks, so I know that isn't the problem. So that's where I am. I am hoping to check the leads on the TPS today with a ohm meter. I know my resistance levels.
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I bought my '07 Passat 2.0T Wagon as a CPOVW 6 weeks ago. It had 4700 miles on it. I complained about the transmission having a delayed engagement when shifting into reverse and drive. (it drives normally however with positive shifts and is very enjoyable) I was told it was normal and not to worry. (could it be designed-in to soften the engagement?).
This week I noticed a light "thunk" in the right front when re-applying power while coasting below 40 MPH. I never noticed it before but I usually strive for smooth driving so that may be why. I've had other Aisin Warners but they were in Volvos. I got out of a '99 Volvo Cross Country because I didn't trust the driveline. Am I going down the same road?
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I have a 1991 bronco with a 351w and the e4od trans.. The transmission is shifting late and hard and sometimes when i let off of the gas to slow down it shifts between gears up and down by itself... The only lights on the dash that are on is the Rear Anti-lock brake light and the speedometer is not working either.. Where to start the trouble shooting to fix it?
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I have a 1998 F-150 XLT, 2WD, 4.2L, V6, just over 103,000 miles. My transmission shifts fine into reverse but when I put it into drive it is very slow to engage, sometimes it doesn't. I have to put it in drive, hold down the brakes, give it some gas and then it will engage and lurch forward. I have check the fluid level and quality. Both are fine. This just started to happen two days ago with no fore warning. No previous problems with transmission.
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My transmission has been shifting rough and seems "delayed" in shift response.
I can only go from gears 1-3 without revving up to 3500-4500 RPM's before it will go ino 4th.
It does not hold RPM in 4, 5, or 6 and instead goes down to the normal idle spot.
I had it diagnosed and the codes are
P0761 Shift solenoid C Performance or stuck off
P0781
1-2 shift error
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Lately my transmission has delayed shifting into first when I shift my car into drive on cold starts. It delays for usually about 2-3 seconds then kicks hard into first. The rest of the shifts are smooth and on time. I've tried replacing my transmission fluid, but that doesn't seem to fix it. Is there an actual problem with my transmission? I had the TCM replaced when it would get stuck and not shift. I have a 2009 GLS with around 53k on it.
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I have a '98 F150 4.2l with 230k miles on it. A couple of days ago when starting, I noticed that the engine kept racing instead of idling down like it normally does and the weather here in Arkansas has approached the 80 degree mark. The engine also doesn't idle down when shifting (I have a manual tranny). Where to start? I don't have any codes stored other than two for bank 1 and bank 2 running lean but they popped up many miles ago. I'm thinking either a vacuum leak or throttle control. I checked the operation of the cable and the throttle valve and they appear to be fine. Maybe the idle air control?
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I brought my truck to ford because I thought I was having transmission issues, but they are telling me that my transmission is fine, that I need to replace my number 8 injector. None of these symptoms sound like injector issues:
-Shifting from park to reverse, takes a couple seconds to shift, then jumps.
-Coming to a very slow stop, truck is a little jumpy at around 2-3 mph
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My auto transmission is sticky at times. This usually happens after an hour of driving doesn't happen all the time. The gears start to change at high Rpms like 5 to 6k. It's real annoying. Otherwise the tranny is very smooth , like butter . Shifts into all gears.
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My MIL is on!!!! I went to Autozone, they told me the error code is P0121. The car is running funny, with uneven idle, and bucking/not shifting.
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Why has my vehicle started making this loud clanging noise when shifting gears? (Automatic) It sounds like someone is hitting a wrench against the metal, most notably between Reverse and Drive. Also, the body of the vehicle is noticeably lower on one side with no flat tires.
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I have a saturn sc1 2001 and the idle is pretty high (2000rpm) what could be the problem ? i already cleaned the IAC ...
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My buddy just bought a vr6 2001 and it has a problem! the previous owner said it had an oil leak and didn't notice it until it started ticking! ok not a big deal! we changed what was left of the oil with semi synthetic 5w20, and put a new filter on it! figured out that the oil was leaking out of the filter gasket , how he didn't notice is beyond me! now the ticking has gotten quiet BUT now it idles high! there is now CEL and the previous owner said it did not do it before the ticking! so my question is how did running low on oil, and POSSIBLY messing up a lifter or two cause it to be idling high? It only idles high in park between 1 and 2000 rpm!
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My nephew's car is a 2002 Hyundai Elantra GLS manual. His RPM's hang when he shifts and it is a pain to shift.
I took it to the dealer and had them do TSB#04-36-011 Delayed RPM drop between shifts. This TSB supersedes TSB 01-36-025. Here is a link for the newest TSB : [URL] ....
The TSB Basically tells them to erase ECM adaption values. Then, you update the ECM with new FUEL cut-off logic. When we drove off the dealers lot the delay was not better, just different.
After driving it for a day or two we saw improvement. Now when you push in the clutch the RPM's go up slightly for a second to burn off the gas then the RPM's drop faster than before.
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I had some problems with my Elantra and I fixed (or tried to) them all this weekend. I needed a new IAC motor, the motor was reving up and down and I tested it, then changed it. I needed a fuel injector and changed that. I needed a lower thermostat housing and changed that.
These changes resulted in the following problems. The vehicle now revs at a high idle all the time at approximately 3000. What are the causes of this?
I know that when I was burping the coolant system (changing out all the hoses and the thermostat housing) I got antifreeze sprayed all over the top of the motor.
Here is the problems that I have now. Didn't have these before.....
The engine idles at or about 3000 rpm. Constant from startup until shutdown. It idles down when you shift it into gear but that is because of the strain on the motor with the brake used.
The transmission is now having problems shifting from 1st to 2nd. I checked the fluid, its good. There is however antifreeze on top of the transmission by some sensors. Do these sensors have anything to do with the shifting?
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2002 Elantra idles high, 2.5 rpm, just when I start it up in the morning. The second I put brake on and put it into gear, it settles down and doesn't do it again until the next morning.
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2004 2.4l engine has high idle speed aprrox. 1000rpm.
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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.
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