I think you got right could be the iacv valve,since I have rough idle as well.
Now what's the next step replace it or clean it?
Car accelerate right after start
- Thread starter Mephy
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Now what's the next step replace it or clean it?
NOT normal. My 2002 Accord did the same thing two years ago and it was a bad throttle body. It was with 20 years and 200k miles and hadn’t been used much 2-3 years leading to that with daily short trips of .25 mile to and from commute lot. Idle rpm was above 2k, which is normal when at speed so a regular person wouldn’t notice it beside poor fuel economy. Normal sub-freezing cold starts would be 1k-1.3k rpm for under 30 seconds and drops to 1.1k or below. Warm Idek should be 1k or below.
Car lurking with high idle is not normal.
Car lurking with high idle is not normal.
You can check if the resistance of the solenoid valve is within spec. There is usually an acceptable range of a few Ohm. If it isn't within specs, replace the ICV.
Replace it. From my experience with Hyundai Genesis - find an OEM replacement part, or it will never work right or cause a permanent check engine light. I got burned by that enough to know that in that car I HAVE to stick with OEM. But the glorious 375hp V8 makes it all worth it.
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What vehicle and engine?
Kia Forte 2014 1.8L Manual Transmission
It may not have an idle control valve if it has an electronic throttle body.
Was the throttle body cleaned? Not just from the front, but from the back which requires TB removal. That's where the gunk actually accumulates.
Was the throttle body cleaned? Not just from the front, but from the back which requires TB removal. That's where the gunk actually accumulates.
Yes it has been cleaned properly, we cleaned the air mass sensor too.I think that I have to warm up the engine with clutch pedal down because if I lift it the rpm goes down.Maybe the computer try to compensate and accelerate too much. I will see if it happens again doing that.
Don’t do that, you will wear out the throw out bearing doing this. RPM drop when you release the clutch is normal, as long as the engine doesn’t seem like it’s going to stall. That’s because the oil in the transmission is also thick so the extra load causes the RPM to drop a little. It’s perfectly normal.
Fwiw if it's Arizona cold outside (below 40f) my car will idle at 1800 (higher if it's even colder) for up to a minute before dropping slowly to 800ish rpm. When the engine is fully warm it idles around 700 rpm. Cable throttle body and clean idle air valve, and it does properly compensate for a/c and power steering loads. I think some cars are just programmed different.
I had a lnline 5 Volvo that would idle at 850 rpm all the time. Even on the coldest starts and hottest days it stayed at exactly 850 rpm.
I had a lnline 5 Volvo that would idle at 850 rpm all the time. Even on the coldest starts and hottest days it stayed at exactly 850 rpm.
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Cold starts requiring a slight bump in rpm normal.
Op stated the car jumps to 4k, thats out of spec and near redline.
I would look at fuel trims, maf at idle, and a huge vacuum leak.
If its old school, check iacv, maf, tps, and tb.
Op stated the car jumps to 4k, thats out of spec and near redline.
I would look at fuel trims, maf at idle, and a huge vacuum leak.
If its old school, check iacv, maf, tps, and tb.
Just for be clear it has happened only 2 times in the last 2 months generally goes normal
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did you check your floor mats? 2 times seems like mistaking the throttle or something else holding down the throttle like a floor mat
I will check but very unlikely, I put echo off I will see if it comes back again.
I'll put my 2 cents in...
I was literally going to ask the same question about my Koup, as I noticed a "couple" times recently I started the kia on pretty brisk mornings (single digits) and it revved to near 3500 rpms out of the blue, I actually thought the same thing the pedal was stuck or something.. really weird is if I "blip" the throttle like a old carbureted job, it levels out quickly, or the computer will level out the rpms automatically over about 15 seconds..
No check engine codes, all monitors are "set" and happy, nothing abnormal showing on live data..
I most likely will not diagnose further unless it were to become a "daily" occurrence..
I was literally going to ask the same question about my Koup, as I noticed a "couple" times recently I started the kia on pretty brisk mornings (single digits) and it revved to near 3500 rpms out of the blue, I actually thought the same thing the pedal was stuck or something.. really weird is if I "blip" the throttle like a old carbureted job, it levels out quickly, or the computer will level out the rpms automatically over about 15 seconds..
No check engine codes, all monitors are "set" and happy, nothing abnormal showing on live data..
I most likely will not diagnose further unless it were to become a "daily" occurrence..
Check the idle air control system. A cleaning of its pintle and the bore on the throttle body may be needed. 4000 RPM is too high even for a cold start.
It's drive by wire, so no IAC
Most likely explanation is a glitch between software and hardware... Possibly something stupid like condensation inside the throttle motor/TPS causing some oddity and the ECM commanding a bunch of rpm
The same thing here hopefully will not happen again, it can be very costly since can be a computer problem, I will see with echo off how it goes since I saw some people having auto cruise speed control problems with echo on.
Is this car kept in the Garage or Outside?
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