Car accelerate right after start
- Thread starter Mephy
- Start date
Normal? I haven’t had a car that doesn’t do that, the colder it gets the more often that happens.
It'is not normal at all.
When is very cold it stays for a while at 1800 rpm, when it start it jumps max 2200 for go down right away, what happen is like I step the foot on the gas. I'm concerned about it since you can damage the engine if it happens at very low temperatures.
4000 rpm though? Sure, most if not all cars increase the rpms a certain amount depending on engine temp, AC compressor compensation, charging requirements, but 4000 rpm is extreme! Especially if it's something that just started happening.
I would start looking for locked up pulley's, locked up ac compressor, bad throttle position sensor, bad throttle body if its a throttle by wire type of setup, bad idle air control if it still has a cable etc.
Well I don’t know then. But all my cars accelerate up to what I think are excessively high levels upon initial start in the cold. I don’t know if it’s 4000 RPM however.
What’s the car in question and what engine? If it has an idle control valve, that would be my first thing to check out.
Maybe clean the throttle body, MAF?
Maybe clean the throttle body, MAF?
My mustang revs a little over 2k for 15-60 seconds when the cats are cold. The computer tells then engine when it can resume regular RPMs based on the cat temperature.
It's a Kia Forte 2014 1.8l I already cleaned the air intake and the mass air flow sensor. This problem happened only 2 times in 2 months
This is what my car does generally
My 2022 Mazda CX5 accelerates but only to almost 2000 RPM but it doesn't say there very long.
While idle speeds at increased RPMs are normal after a cold start for a short while, 4,000 RPMs seems too high. My BMW limited RPMs to no more than 3,100 after any cold start. As engine temperature increased, the RPM limit went increasingly higher until it was lifted. I have seen around 2,500 RPM idle speeds after cold starts at sub-freezing temperatures but not more than that.
has it been 2 of the coldest days? I bet Kia has something built in to warm up quicker by generating higher RPMs. Unless it is super cold, I doubt this would ever be an issue.
It is a problem that I have find out what is the cause of this sudden acceleration while is warming up.
Something's going wrong with air or fuel delivery is my guess. A problem with the throttle body? Sticky idle air control valve? Have you checked for vacuum leaks? No CEL?
Back when all that was in the news the floor mats were blamed. Its always been an electronics or software issue.
Your car obviously has a "fly by wire" throttle control. Were you stepping on the brake when it happens?
Does the car have vehicle stability control?
Your car obviously has a "fly by wire" throttle control. Were you stepping on the brake when it happens?
Does the car have vehicle stability control?
4,000 rpm is high to idle up to on its own. Something is wrong, I'd start looking by checking for codes, vacuum leaks, etc.
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That kind of RPM requires the throttle valve to be opening. I'd start with a good cleaning of that thing. They're very delicate so don't be forcing it open or poking anything down inside. They have coolant running to them so remove the thing and clean it properly.
Check the signal coming from the gas pedal too. There might be corrosion on the rheostat causing a brief blip on the throttle.
Check the signal coming from the gas pedal too. There might be corrosion on the rheostat causing a brief blip on the throttle.
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sticky throttle bad iacv?
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