Why does engine rev up and down when I step on brake?
My engine isn't missing at idle or acceleration. When I step on the brake it revs up and down as if it is going to stop, but it doesn't. I let off the brake it revs/runs fine...
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There are several different causes depending on the year and engine. If you provide that, I can steer you toward a possible solution. Let me know the year, engine model, and whether it is carbureted or fuel injected.
Some causes:
-vacuum leak
-egr valve damaging fuel line (Toyota recall)
-fast idle valve coolant tube clogged
-fast idle adjustment
-throttle position sensor malfunction
FYI
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My car is a Suzuki Verona 05 and it's doing the same thing almost like my pedal was stuck or is sticking
andrea, I would suspect a possible issue with the electronic throttle pedal switch.
shannon, yours sounds like a idle air valve or possibly an egr valve issue. You both will want to be taking it to a good mechanic.
Mine is a 2005 Elantra. Its like I'm in the wrong gear or trying to accelerate on the clutch... It only starts happening after I've been driving for ~15 min, faster if I've been on the highway.
MIne is a 2012 Camaro. When I push the brake pedal to put in gear the car goes crazy with lights on the dash and it will not go in gear. There's clicking under the dash when I depress the pedal
Mine is a 1999 Honda Accord ex and when I push the brake the engine revs up to 1000 rpm and then drops down, it also makes a air leak sound when I press the brake petal.. the motor does have a air leak sounds coming from behind the head
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I own a 1988 4X4, with 6 cylinder 3VZE engine and a Manual (Standard) transmission without Cruse Control. The answer lies on p.28 of the Toyota Electrical Wiring Diagram Manual. I was able to clip and tape (1) wire to cure the problem.
My truck would rev up like I was maxing the gas at every stop light. As soon as I got off the brake, everything would go back to normal. I was looking at replacing my $1000 TCCS module but it cured the problem.
If you have an Automatic transmission with Cruse Control it won't work.
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What did you do? Which wire? I'm having the same problem
I have a 2006 Ford Mustang v6. Idles up and down with a soft pooping from the tail pipe Plisk when applying the brake it idles ups to 2 thousand to 1000 until the car stops then goes back to normal
Hello please i have e60 2007 and if i press the break pedal the engine RPM goes up and down and in a time he goes to turn off the car
And if i press the gaz pedal the RPM rises slowly
Plese if any one can help me!! Thank you
Ali,
I think your problem is with the throttle position sensor. Since that is what tells the computer how much throttle you want, if the signal is intermittent or just plain wrong, the computer is trying to compensate. The slow throttle response is the give away, I think.
I have a 92 pickup Isuzu with four-wheel drive that everytime I depress the clutch the engine revs up and down
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I was able to fix this problem when it happened to my 1988 Toyota Custom Cab - 3VZ-E V-6 engine - standard transmission - no cruise control. If you have access to the 1988 Toyota Electrical Wiring Diagram manual, you can find the circuit that's giving you the problem on page 28 (TCCS section 6-1). You start at a 15 amp fuse (15A STOP) that feeds the STOP brake light switch (brake switch). You go through the switch, to connector N5 terminals 4 & 5 (you can check your brake switch function here - 8-14 volts when the brake is applied). You go through N5 and end up at the TCCS ECU module (Toyota Control Computer System - Engine Control Unit) terminal STP-6 under the dash on the passenger side.
This STOP brake light switch wire is not the one that activates your brake lights - it feeds a signal to the TCCS that tells the (AUTOMATIC) transmission to reset to idle and prep to go into 1st gear. I have a MANUAL transmission - and every stop light I came to, sitting there with my brakes on, would rev the engine up so high that everyone was wondering what the idiot in the Toyota Truck was doing. I talked to a Toyota Engineer and told him I was going to clip & tape the wire going to terminal STP-6. After looking through the prints with me, he said - since it was a MANUAL transmission - it looked like it would work. I clipped & taped it - the problem went away and I still drive my 1988 Toyota Custom Cab happily every day.
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I have a 1992 Honda Accord and when I start to warm up or stop it revs up and down . My cousins husband says it’s some type of the switch but I don’t know what kind of switch he’s talking about. He says with that reving, it’s wasting gas. It says it only takes about 15 minutes to fix. Any idea of what switch he’s talking about
If he can’t tell you the name of the switch then he probably doesn’t know what he’s talking about.
Amanda, Mike Hunt and all other Honda people with a hunting idle. The FITV, fast idle thermal valve is not closing all the way so it allows extra air into a warm engine, when the computer sees a high idle and the speed is zero, it turns off the fuel injectors so the idle goes back down and this cycle repeats giving you a hunting idle. If you remove the metal cover, 2 screws, you will see a screwdriver slot, screw it down until the air gap is closed in this valve. Inside the FITV is a wax pellet, it gets heated by the engine coolant, antifreeze, and when it gets heated up it expands pushing the FITV closed. When the wax gets old it does not expand as much so when you adjust the valve yourself, this is only a temporary fix, it will get worse and the entire valve will eventually need replaced. Be sure to get all the air out of the coolant passages or it will not work correctly, as a matter of fact, bleed the valve now and see if it works next drive or not, then make the adjustment knowing its only a temp fix.
I think you have bad coils
My is a 1934 Ford with 25 years of new life and less than 55,000 miles. It has all Ford running gear, C4, 8.8 rear. 302 ci engine, aluminum heads, headers, air gap intake, 600cfm Demon, and MSD. This problem just started today, and I did find one vac leak but no cure. The car does have good a/c and I have drove it a lot this week. I realize this is out of the norm, but thanks a lot for any help….
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I would say you still have a vacuum leak somewhere. With everything hooked up normally and the engine running, use a propane or butane torch (just the gas, no flame) and run over all the vacuum lines. If the engine revs up, you have found your leak.
Hi my Ford mk2 Escort Rs 2000 I have twin 45 Webber’s when I put foot on brake pedal slow down the engine revs up can you help please many thanks Norman
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Not always a vacuum leak most times is a dirty or broken mass air flow sensor / The pcv valve
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My own is Honda accord 1997. If I start my car in the morning it will started jerking at very low level and after some minute drive it will balance. And driving it to long distance, it will now started working on high level. Pls what cause the problem.
Godwin you need to pour Blue Devil bottle in the radiator your head gasket is leaking
Hello I have a2012 mustang 5.0 with a coyote motor V8 and it will not go reverse or forward unless I rev up motor and it will jump forward and reverse but it is very dangerous I gotta make sure nobody is in front or behind it was fine but now it’s getting worse help please
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anyone with an answer?
由 Joe Henry 完成的
I have had this problem also.
由 stoco 完成的
I have the same problem it's a leak in the break booster so when u hit the breaks it's letting extra air into the engine and therefore revving check for a suction,vacuum sound right behind the break pedal when braking it shouldn't be there. If this all matches replace your break booster
由 Josh Wheeler 完成的
I have the same problem but I was also wondering if when it revs it wastes more gas, so I could replace asap. (It’s been using more gas than usual)
由 Pablosoria 完成的
I am a mechanic and the most common problem to agree with the above comment it is a brake booster
由 Christopher Tha King Hogan 完成的
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