Engine Surging or Misfiring

Engine surging or misfiring up and down while you’re driving.

Uneven engine revs and misfiring can affect drivability, but can also cause error codes to appear in your OBD-II Diagnostics system.

These codes can cause you to fail your local vehicle inspection, or at the very least can result in that very annoying Check Engine Light coming on.

The good news is that in many cases an engine that is running poorly can be repaired for very little money.

Engine Surging or Misfiring
Engine Surging or Misfiring
  • P0300       Random/Multiple Cylinder Misfire Detected
  • P0301       Cylinder 1 Misfire Detected
  • P0302       Cylinder 2 Misfire Detected
  • P0303       Cylinder 3 Misfire Detected
  • P0304       Cylinder 4 Misfire Detected
  • P0305       Cylinder 5 Misfire Detected
  • P0306       Cylinder 6 Misfire Detected
  • P0307       Cylinder 7 Misfire Detected
  • P0308       Cylinder 8 Misfire Detected
  • P0309       Cylinder 9 Misfire Detected
  • P0310       Cylinder 10 Misfire Detected
  • P0311       Cylinder 11 Misfire Detected
  • P0312       Cylinder 12 Misfire Detected

Performing maintenance tasks like replacing worn spark plugs, inspecting plug wires, or even replacing an old, partially clogged fuel filter can make a huge difference in how well your engine is running.

Having an engine that performs well can save you a bundle of money. Even one hour of diagnostic time at your local repair shop can put a large hole in your wallet.

The list of symptoms and possible causes below should help you get a better idea of what’s causing your engine to act up.

If you see a symptom that looks familiar, read on to find out what a possible fix can be. A cheap fix is always preferable to an expensive repair bill.

Here are Some of the Possible Engine Symptoms and Causes,


While you are moving the engine misfires or surges.
The engine seems to start fine and will normally accelerate fine.

As you are driving and maintaining a steady speed, the engine seems to “speed up” slightly or it seems to miss and buck.

Any of these could be possible causes:

  • If you have a carburetor, the choke may not be set properly, or the choke may not be working correctly.
    The fix: Check the choke plate and make sure it is opening completely.
  • The engine may be running too hot.
    The fix: Check and repair cooling system.
  • The fuel pressure regulator may be operating at low pressure.
    The fix: Check fuel pressure with a fuel pressure gauge. Replace fuel pressure regulator. (Generally not a DIY job)
  • Your ignition timing may be set incorrectly.
    The fix: Adjust ignition timing.
  • Ignition system problem causing a weak spark.
    The fix: If your vehicle has them, check and replace distributor cap, rotor, ignition wires and spark plugs. You should most likely have the coil packs looked at.
  • There may be a fault in the computerized engine control system-Check engine control systems with a scan tool. Test circuits and repair or replace components as required. (Generally not a DIY job)
  • The fuel filter may be partially clogged. This is an easy fix!
    The fix: Replace the fuel filter.
  • Torque converter (automatic transmission only) may not be locking at the right time, or it may be slipping.
    The fix: Check lock up circuit or replace torque converter. (Not a DIY job)
  • There may be a vacuum leak.
    The fix: Check and replace vacuum lines as required.
  • Possible internal engine problems.
    The fix: Check compression to determine engine condition.
  • EGR valve could be stuck open.
    The fix: Replace EGR valve.
  • You may have loose or worn drive axles.
    The fix: Check and replace CV/universal joints as required.
  • The fuel injectors may be dirty.
    The fix: Clean or replace fuel injectors.

Engine Surging or Misfiring could be just the start of your problems. Having an engine that performs well can save you a bundle of money.


About Danny Bender 138 Articles
DannysEnginePortal.com Is The Premier Automotive Engine Troubleshooting Resource Site. DannysEnginePortal.com Shares Information On Engine Troubleshooting, Engine Rebuilding, Engine Repair Tips, Tech Info, Basic Machining, Automotive Testing, In Addition To Possible Solutions.

1 Trackback / Pingback

  1. What to Check When your Idle Speed Is Too High • Welcome to DannysEnginePortal.com

Leave a Reply