Q: I have a Audi 100 Quattro that surges while you drive once in awhile. You turn the car off and start it and a drives just fine. An

asked by on

When driving my car for a period of time it will start to Surge I can stop turn it off restart it and it drives just fine for a while or if I sit in idle for longer than 10 minutes it will start to this surge is this a fuel pressure regulator issue or fuel pump issue?

My car has 200678 miles.
My car has a manual transmission.

Hi There, It sounds like this may be related to misfire of some kind which may be triggered by a fuel pressure problem, but could also be triggered by many other things as well. Engine misfires can be caused by many different problems and are generally caused by either a spark or fuel issue or in some cases, a combination of both. Spark related problems generally will result from things like ignition coils, crankshaft position sensor, spark plugs, spark plug wires or ignition modules not working properly. When the misfire results from a fuel related issue, this is commonly related to a lean fuel condition (lack of sufficient fuel supply to the motor). Fuel related misfires can be caused by many different things such as low fuel pressure, faulty or dirty fuel injectors, a faulty O2 sensor, a dirty or failing mass air-flow sensor, a faulty or dirty idle air control valve or a vacuum or intake leak. When the fuel supplied to the combustion chamber is insufficient, this results in an ignition (spark) that is igniting a less than balanced load of fuel and air. This results in a misfire or an explosion in the cylinder that is much less powerful than the other cylinders. This creates a loss of power that resonates throughout the motor additionally causing other problems with ignition and fuel timing. Due to the number of different things that may cause an engine misfire, the quickest and easiest way to diagnose this type of problem is to hook the vehicle up to a scanning tool which will download any potential fault codes that may have registered in the vehicle’s computer as a result of the poor running condition. I would recommend having an expert from YourMechanic come to your location to diagnose your misfiring problem.

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. I have a Audi 100 Quattro that surges while you drive once in awhile. You turn the car off and start it and a drives just fine. An

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: Fuel pressure low

Hi! I would recommend having a technician double check the fuel pump, filter, fuel lines, fuel related wiring, and fuses. It's always best to double check components pertaining to an initial concern in case something was missed. Also, there is...

Q: Crankshaft seal leaking

Hi there. Unfortunately oil leaks can come from so many spots. It is common for the front crank seal to leak as well as the rear main seal and the valve cover gaskets. If the location of the leak is...

Q: Trouble Starting Audi A4

If you have the cam belt timing off, it will make the car difficult to start, but that wouldn't effect the fuel pump function. and you would notice that the car runs poorly when it is running. So from here...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...