Q: Violent surging from rough idle after cleaning throttle body and putting in gas

asked by on

The van has stalled 2x when stopped at a light, seems to coincide with letting my foot off the break. It starts again just fine. Also stalled when breaking in a parking lot and in a gas station. After cleaning throttle body and the iac valve, the van seemed to have a smoother idle. I noticed the van didn't have a throttle body cover or a gasket between the IAC motor and the intake passage. I placed a gasket b/w the IAC motor and the intake passage but still no gasket cover. Anyway, gas was on E. I put 1 gal. in the tank, the van sounded the same, and I noticed white emissions for the 1st time. Later, I filled the tank to 3/4 full, then stalled in the station. I then stalled at a stoplight. Later, in my driveway, with my foot on the break, the van's surges were the worst I've heard and felt. Each surge moved the van forward as if being pushed from behind while in park and in drive. I'm afraid to drive it. Any help is MUCH appreciated!!!

My car has 177000 miles.
My car has an automatic transmission.

Hello and thank you for contacting YourMechanic. You may want to perform a tune-up and change all of the spark plugs and wires first. Then check for vacuum leaks on the engine with a vacuum gauge. If the vacuum gauge reads less than 15 hg, then look for any vacuum hoses that may be disconnected or cracked.

A vacuum leak will stall out the engine and cause a rough idle. If you need assistance with finding a vacuum leak, then seek out a technician, such as one from YourMechanic, that can diagnose your rough idle and assist you with fixing your vehicle.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Violent surging from rough idle after cleaning throttle body and putting in gas

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: I have changed the crank shaft sensor but the car still keeps stalling. What else could be wrong.

Hello. You should also try checking the camshaft sensor as this also performs a similar function in that it monitors the camshaft speed which tells the computer how to regulate ignition and fuel injection timing much like the crankshaft sensor....

Q: How do you reset a IAC valve in a 97 Jeep Grand Cherokee?

Make sure the engine is at operating temperature. Then you need to set the idle stop on the throttle body to the lowest setting, unless it is already there. Then to fully extend the IAC, jumper ALDL pins A and...

Q: Car won't start just one click when key is turned.

The first question you should ask, is why the terminals were melting in the first place. This is a sign something is wrong and this issue needs to be corrected, or the new battery may meet a similar fate. It...

Related articles

P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...