Motor Vehicle Maintenance & Repair Stack Exchange
Motor Vehicle Maintenance & Repair Stack Exchange

Questions tagged [misfire]

A condition where one or more engine cylinders experiences lack of combustion or mistimed combustion through detonation

This condition can be experienced due to a multitude of possible issues from ECU, wiring harness, fuse panel, signal generator, spark plug wires, points, condenser, igniter box, spark plug cap or any number of related ignition components.

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How does the car's ECU detect a misfire?

I was wondering what the specific mechanism used by car ECU's to detect misfires is, or are if there is more than one method.
Robert S. Barnes
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Can (possible) exhaust system damage cause random misfires?

2001 Honda Prelude SH. About three weeks ago while travelling 10-15 mph I pulled off the side of a dirt road to park and it turns out there was a row of a few railroad ties laying in the grass there. The ties ran just inside the right tires, with…
Jason C
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Do these coil on plug waveforms suggest I have a bad engine controller?

I have a missfire on cylinder 3. I have swapped the coil from cylinder 6 and 3, but the missfire remains on cylinder 3. I have also done the following: - replaced all spark plugs. - checked the wiring harness resistance all the way back to the…
Rick Gostlin
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How does low oil level cause misfires or VTEC malfunctions?

So a few days ago my 2003 Honda Civic EX started misfiring while accelerating, especially with the A/C turned on, making popping noises, and then yesterday got a P1259 "VTEC system malfunction code". Web forums said to check the oil level, so I did…
endolith
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Astra MK6 - when warm, rough idle and shudders while accelerating

Here's a video: https://youtu.be/wYyaW9wRt6U For a couple of months now my car has had a rough idle and shudders while accelerating - Vauxhall Astra J Exclusiv MK6, 4 years old 61k miles spark plugs done last year. It starts off shuddering if I…
codaamok
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04 GMC Savanna G2500 4.8 V8 No Power

First time I looked at this the A/C compressor clutch wasn't engaging. Long story short: the high side pressure switch on the back of the compressor was unplugged. Noted that the engine was shaking (like it was misfiring) as I was watching them add…
Ben
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Cylinder misfire after leak down test

I am getting cylinder misfire OBDII error codes after performing a cylinder leakdown test. During the test, I was turning the crankshaft to reach TDC for each cylinder and I'm now thinking whether it needed to be readjusted again (to a startup…
amphibient
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The Mystery of the Misfiring MINI

It's me again. 2008 MINI Cooper S w/ dealer-installed JCW package (chip tune, larger air intake, larger cat-back exhaust). I thought everything was fine after resetting my ECU last week, but had bad misfiring at idle again this morning which set the…
Spivonious
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Cause of limp mode in Vauxhall Astra which ECU code is relevant?

The engine now runs ok when started cold, but if the weather is very hot or it's started when warm it goes into limp mode, whereby the orange spanner symbol comes on and max acceleration is only 1/3 it should be. I thought it was caused by oil…
BrianTheTallOne
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2004 Saturn ION with Ecotec 2.2: Engine misfire with code P0300, ICM problem?

Car came in with a misfire complaint and check engine light on with code p0300. Looking at misfire history confirms high misfire counts on cylinders 1 and 4 along with lower counts on cylinders 2 & 3. Fuel trims OK LTFT < 10. Plugs are…
Ben
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Random Misfiring - Tried All Basic Fixes - Tech Says Engine Ground

Starting about a week or two ago, my 3.4L engine (2004 Chevy Monte Carlo LS) has thrown a p0300 code, random misfire. Here are the things I've done: Changed spark plugs and wires Knocked fuel injectors (tapped them with screw-driver and hammer)[it…
Bashkir
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Should misfire counts be zero?

'07 Cobalt LS, 2.2 L I-4 Car is not getting a misfire code. (p030x) However, the mode 6 data shows Non-zero "misfire counts" on all cylinders. The counts are single- or double-digits, and are very low at highway speed. I don't feel any misfires,…
George
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Black Spark Plugs that Clean Themselves

Vehicle: 2002 Mazda Protégé LX, 2.0L engine, automatic transmission, 240,000 km Recent Work: Thermostat replacement Symptoms: Owner reported that the car shook and stalled on startup. She parked the car and drove another vehicle. The next day, the…
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Highlander Hybrid losing oil/coolant

I've received a variety of opinions regarding what may actually be wrong with my car. Here is the story so far... Sep. 2016: ~96k miles: Bought 2008 Toyota Highlander Hybrid from dealership. One owner, full service history, nothing major replaced…
Avalanche
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Can Getting Fuel Injectors or Ignition Coils Wet Ruin Them?

I have a 2005 Suzuki Forenza Wagon where I recently cleaned the engine compartment. I was a little careless during the cleaning and water got in under the spark plug wires to sit around the top of the spark plugs in the head. As can be imagined this…
Dalton D
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