This article will discuss the likely reasons why your Honda Civic jerky when you let your foot off the gas pedal. If you feel this jerk when you immediately take your infantry off the gas after accelerating ( with no feathering ) or you barely press the gas enough to begin accelerating, follow the diagnostic steps below. The cause might be equally bare as a dirty detector, or as far gone as an significant locomotive component .
Step 1 – Check for DTC codes
On-Board Diagnostic ( OBD-II ) scanners connect to a vehicles engine control condition unit ( ECU ), and reveal any problems the fomite may have. The scanner reveals Diagnostic Trouble Codes ( DTC ), which correspond to a particular problem within the vehicle and its possible placement. If you have an OBD-II scanner, connect it to your Civic ‘s ECU, which is located behind the kick panel of the passenger ‘s side foot well. Costs for these scanners start at $ 20. If you do n’t own a scanner, most local car parts stores will scan your car for DTC at no monetary value.
There are two main codes to look for if your car jerks when letting off the gas pedal :
- P0120: Throttle Position Sensor (TPS) – This sensor disables temporary fuel enrichment on acceleration, which may cause hesitation or stalling.
- P1508 or P1509: Idle Air Control (IAC) Valve – This could mean you have a defective circuit or unplugged/defective sensor.
If your scanner reveals an unrelated code, you should address that equally soon as potential. The price to replace the TPS runs between $ 20 to $ 100, and a substitute IAC valve runs between $ 60 to $ 170. Follow Steps 2 or 3 to inspect the TPS and IAC valve, respectively .
Figure 1. OBD-II scanner for Honda Civics (1996-2000).
Step 2 – Inspect throttle position sensor (TPS)
inaugural do a ocular inspection, and look for any fray wires or informal connections. If the TPS is disconnected, unplug the detector, drive the car, and observe if the problem persists. If the problem goes aside with the TPS unplugged, either the wiring or the detector itself is faulty .
Use a multimeter to test the wiring for continuity. Test the middle wire of the detector ( Throttle Position Signal ), and look for any dead zones where actuating the restrict body linkage does n’t cause a change in electric potential. If you find any dead zones, trace the cable back and check for any breaks. In either of these cases, the TPS will need to be replaced.
Figure 2. Honda Civic’s throttle position sensor.
Step 3 – Check the idle air control (IAC) valve
You should first clean the IAC valve. To do so, remove it from the back of the intake manifold to the spray it with bracken uninfected. Wait until the dirty fluid stops flowing out of the IAC valve, let it air dry, and re-install it. If the trouble however persists with a clean IAC valve, you will need to inspect its cable harness. Look for any frayed or break wires, and replace it if necessary .
Figure 3. Spray brake cleaner into the IAC valve’s two holes (marked by yellow arrows).
Featured Video: How to Fix and Replace IAC
Step 4 – Inspect the throttle body
beginning, you should clean the choke body to make certain it ‘s not the source of the problem. By cleaning up all the carbon buildup, the strangle body will be able to move air more freely, and the chat up valve will be able to actuate more smoothly. To clean the accelerator body, remove it and use bracken clean with a wire brush to remove all the carbon buildup .
To test if the butterfly valve is actuating smoothly, re-install the restrict body trip to the choke linkage by hand. A by rights serve choke soundbox will move smoothly. If you see any flat spots or abrupt movement, you will need to adjust the strangle linkage.
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- Figure 4. A dirty versus a clean throttle body.
- Figure 5. Throttle body linkage
Featured Video: How to Fix Throttle Body
Step 5 – Check the motor mounts
Broken or idle drive mounts can lead to all sorts of erratic vibrations. Lift your Civic onto mariner stands, and inspect the motors mounts underneath the engine for cracks, missing nuts, or loose bolts. Some cracks in the motor mount may be hard to see. Insert a piece of paper in between the mounting plate and the frame to check if there is a gap. If so, the motor saddle horse ( second ) will need to be repaired or replaced. New ones price anywhere from $ 50 to $ 500 .
Figure 6. Loose bolt in the motor mount.