Why does my engine rev high when I start it?

Common causes of high RPM excursion at start-up are typically: large vacuum leak, throttle plate stuck open, cruise control stepper motor stuck in one position; faulty throttle position sensor, and/or faulty idle air control motor or solenoid.

Why does my RPM go up while in park?

The idle is controlled by the idle air control valve and if it cannot keep the engine idling it will keep trying to rev the engine up to compensate. The most likely issue here would be a faulty idle air control valve. This can cause the RPMs to rise when the transmission is in park and the engine is just idling.

Why does my RPM go up and down while driving?

For the engine surging making the rpm’s go up and down could be caused by a defective or stuck idle air control valve (IAC). Check the IAC and see if it’s working. Remove the vacuum line to the valve and see if the engine runs smooth.

What RPM should my car be at 70mph?

Generally, the average car stays at about 2500 rpm while doing 70mph.

What causes my RPM to fluctuate?

If your RPM fluctuates while accelerating, it could be because your spark plugs have gone bad on you. Worn-out spark plugs can cause misfires to occur within your engine, and those misfires can lead to your engine vibrating a whole lot. Those vibrations can lead to the RPM in your engine going haywire on you.

How do you fix a surging idle?

Turn the engine off again, and reattach the air intake duct work to the throttle body. Start the engine and rev and hold to 1,500 to 2,000 rpm until no white smoke is coming out of the exhaust pipe. Cleaning the Idle Air Speed Control Valve with aerosol throttle cleaner can often solve an idle problem.

Is it normal for RPM to fluctuate?

Oftentimes, when your RPM fluctuates while accelerating, it’s going to be because of an issue with the idle air control valve, or IAC, in your car. The IAC is in charge of controlling the idle speed of your engine, and it could be the reason why your tachometer is out of control right now.

Can a vacuum leak damage engine?

When the vacuum leaks, it cause undue damage to the engine, thus causing an uncomfortable drive and possible engine failure. In order to properly identify whether or not your vacuum is leaking, it’s best to consider the answers to the following questions: Is my engine stalling?

Why does my car not shift into third gear?

Such a problem is automatic transmission won’t shift into 3rd gear. The transmission shifts into the first and then to second gear but does not move into the third gear. It seems that the gear slips into neutral when you push it to the third. Another instance could be the automatic transmission won’t shift into 3rd gear at all.

When do you start the car, the engine revs?

Car engine revs way up immediately upon starting engine. Q: Car engine revs way up immediately upon starting engine. When starting the engine, it sounds like you have your foot pressed to the floor on the gas pedal as soon as you start it, without even having your foot on the gas.

How does a solenoid get power to shift gears?

The transmission control module (TCM) — the brains of the transmission — will send power to one of the shift solenoids in order to shift gears. Inside the solenoid, there’s a plunger surrounded by a magnetic coil.

Why does engine rev up and down when I step on the brake?

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…

Why does my Chevy Cavalier stall at 70 mph?

This week on I-84 at 70 mph, car dies. Was able to coast of an exit ramp. Pulled over, opened the hood, shook the connector, it started right up. Drove it the rest of the week with no issue. Can’t figure out what the deal is, but it is either a connection in the harness, or one of the wires is loose, but it is near impossible to tell.

What’s the problem with my Chevy Cavalier Rs?

I have a 91 Chevy Cavalier RS, 2.2 L. Recently, I’ve noticed an intermittent problem when starting the car (both cold start and warm start). I thought at first it might have been the key, because the keys we had were cheap, badly made Wal-Mart copies so we had a locksmith make an exact replica from the manufacturer’s guide he had.

Why is my Chevy Cavalier running out of gas?

I forgot it running, it ran out of gas and sat until the battery went dead with the key in the “on” position. Now it won’t start. Security light, check gauges and service lights all stay on. Gas gauge doesn’t register any gas (I put 4 gallons in). Very little gas pressure. Has power to the ICM. No power to fuel pump. Any ideas? Thanks.