My 96 chevy blazer has a code ''random 4 misfire'' only misses when in park or idleing at a light. is this and injector issue?

If it blinks and goes away, it is a "random misfire" that culminates before the light begins blinking. Sustained misfiring will result in a code, and the light staying on. If the light blinks and goes away, the issue is intermittent. Your problem usually occurs under acceleration or heavy load. The issue can often be solved with new spark plugs, though it could also be dirty injectors. The injectors on that vehicle are infamous, however I have been able to fix your problem with repeated use of highly concentrated fuel system cleaner. I use at least 3 times the recommended concentration of whatever cleaner. People rave about Sea Foam. I have used it and it works -- though I can't say whether it worked better than other brands I have used. I have owned 3 Blazers and 2 S-10's, including my current 2001 Blazer LT.

ENGINE MISFIRE

There are few possibilities that can cause engine misfire issues. It can be issue with spark plugs or faulty spark plugs. Also get the compression test done for cylinders. If any of cylinder shows low compression then required, then that particular cylinder will cause misfire.

Also get obd codes scanned, the error code will let you know which cylinder is misfiring or all cylinders are misfiring.

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For your trouble shooting I suggest you to refer the help oinks below. It has step by step details for many engine misfire issues.

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Click the link below:-----

Ford Explorer Cylinder Misfire?

http://whoisbyme.blogspot.in/2012/06/ford-explorer-cylinder-misfire.html

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Engine Misfire codes on Chevrolet Malibu?

http://schematicsdiagram.blogspot.com/2011/12/engine-misfire-codes-on-chevrolet.html

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Cylinder 6 Misfire?

http://howtobyme.blogspot.com/2011/12/cylinder-6-misfire.html

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Misfire on cylinder 4?

http://schematicsdiagram.blogspot.com/2011/12/misfire-on-cylinder-4.html

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While stop engine idles like cylinder missing?

http://schematicsdiagram.blogspot.com/2012/01/while-stop-engine-idles-like-cylinder.html

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Ford Explorer 5.0L: Engine Miss?

http://whoisbyme.blogspot.in/2012/06/ford-explorer-50l-engine-miss.html

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Oil on spark plugs and car misfires?

http://technoanswers.blogspot.in/2012/02/oil-on-spark-plugs-and-car-misfires.html

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Can cylinder misfire Damage the Catalytic converter?

http://schematicsdiagram.blogspot.in/2012/02/can-cylinder-misfire-damage-catalytic.html

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Car misfires and error code P0306 and P0303 is shown?

http://technoanswers.blogspot.com/2012/01/car-misfires-and-error-code-p0306-and.html

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Chevrolet K1500 No spark, random misfire

http://repairhelpcenter.blogspot.com/2012/11/chevrolet-k1500-no-sparkrandom-misfire.html

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2004 Ford F150: Engine Misfire and Lean Code?

http://whatisbyme.blogspot.in/2012/05/2004-ford-f150-engine-misfire-and-lean.html

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1995 Toyota LS: Misfire at idle or low RPM

http://whatisbyme.blogspot.in/2012/04/1995-toyota-ls-misfire-at-idle-or-low.html

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Toyota Corolla: Random Misfire?

http://technoanswers.blogspot.in/2012/04/toyota-corolla-random-misfire.html

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2006 Ford Freestar: Misfire on Cylinder Number 2?

http://whatisbyme.blogspot.in/2012/06/2006-ford-freestar-misfire-on-cylinder.html

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This will help.

Thanks.

There are few possibilities that can cause engine misfire issues. It can be issue with spark plugs or faulty spark plugs. Also get the compression test done for cylinders. If any of cylinder shows low compression then required, then that particular cylinder will cause misfire.

Also get obd codes scanned, the error code will let you know which cylinder is misfiring or all cylinders are misfiring.

-----------

For your trouble shooting I suggest you to refer the help oinks below. It has step by step details for many engine misfire issues.

----------

Click the link below:-----

Ford Explorer Cylinder Misfire?

http://whoisbyme.blogspot.in/2012/06/ford-explorer-cylinder-misfire.html

---------

Engine Misfire codes on Chevrolet Malibu?

http://schematicsdiagram.blogspot.com/2011/12/engine-misfire-codes-on-chevrolet.html

---------

Cylinder 6 Misfire?

http://howtobyme.blogspot.com/2011/12/cylinder-6-misfire.html

------------

Misfire on cylinder 4?

http://schematicsdiagram.blogspot.com/2011/12/misfire-on-cylinder-4.html

-----

While stop engine idles like cylinder missing?

http://schematicsdiagram.blogspot.com/2012/01/while-stop-engine-idles-like-cylinder.html

----------

Ford Explorer 5.0L: Engine Miss?

http://whoisbyme.blogspot.in/2012/06/ford-explorer-50l-engine-miss.html

-----------

Oil on spark plugs and car misfires?

http://technoanswers.blogspot.in/2012/02/oil-on-spark-plugs-and-car-misfires.html

------------

Can cylinder misfire Damage the Catalytic converter?

http://schematicsdiagram.blogspot.in/2012/02/can-cylinder-misfire-damage-catalytic.html

------------

Car misfires and error code P0306 and P0303 is shown?

http://technoanswers.blogspot.com/2012/01/car-misfires-and-error-code-p0306-and.html

-----------

Chevrolet K1500 No spark, random misfire

http://repairhelpcenter.blogspot.com/2012/11/chevrolet-k1500-no-sparkrandom-misfire.html

-------------

2004 Ford F150: Engine Misfire and Lean Code?

http://whatisbyme.blogspot.in/2012/05/2004-ford-f150-engine-misfire-and-lean.html

-----------

1995 Toyota LS: Misfire at idle or low RPM

http://whatisbyme.blogspot.in/2012/04/1995-toyota-ls-misfire-at-idle-or-low.html

--------------

Toyota Corolla: Random Misfire?

http://technoanswers.blogspot.in/2012/04/toyota-corolla-random-misfire.html

----------

2006 Ford Freestar: Misfire on Cylinder Number 2?

http://whatisbyme.blogspot.in/2012/06/2006-ford-freestar-misfire-on-cylinder.html

-----------------------------

This will help.

Thanks.

It is hardly ever the spark plug or only the spark plug - generally for some reason there is a weak or lost spark and the reason must be found and rectified by carefully checking and then replacing any components found to be edfective - plug wires, coil, distributor cap, rotor (if fitted), wiring, connections and could conceivably even be the ECU. Perhaps the misfire is due to injector trouble...

Sometimes a fault with persist even after it has been "cured" until the fault code is erased with diagnostic equipment.

Hi Jason:
A Random/Multiple Cylinder Misfire Detected unfortunately doesn't tell you specifically which cylinder(s) is/are mis-firing, nor why.

A code Random/Multiple Cylinder Misfire Detected may mean that one or more of the following has happened:
Faulty spark plugs or wires
Faulty coil (pack)
Faulty oxygen sensor(s)
Faulty fuel injector(s)
Burned exhaust valve
Faulty catalytic converter(s)
Stuck/blocked EGR valve / passages
Faulty camshaft position sensor
Defective computer

Possible Solutions:
If there are no symptoms, the simplest thing to do is to reset the code and see if it comes back.

If there are symptoms such as the engine is stumbling or hesitating, check all wiring and connectors that lead to the cylinders (i.e. spark plugs). Depending on how long the ignition components have been in the car, it may be a good idea to replace them as part of your regular maintenance schedule. I would suggest spark plugs, spark plug wires, distributor cap, and rotor (if applicable). Otherwise, check the coils (a.k.a. coil packs). In some cases, the catalytic converter has gone bad. If you smell rotten eggs in the exhaust, your cat converter needs to be replaced. I've also heard in other cases the problems were faulty fuel injectors.

Random misfires that jump around from one cylinder to another (read: P030x codes) also will set a P0300 code. The underlying cause is often a lean fuel condition, which may be due to a vacuum leak in the intake manifold or unmetered air getting past the airflow sensor, or an EGR valve that is stuck open.

Hope this helps; also keep in mind that your feedback is important and I`ll appreciate your time and consideration if you leave some testimonial comment about this answer.

Thank you for using FixYa, have a nice day.

For engine misfiring problem check the help links mentioned below. Click the link below to go through the troubleshooting procedure :---- No pulse to injectors? http://technoanswers.blogspot.com/2012/01/no-pulse-to-injectors.html
---------How to Test and Replace Fuel Injectors? http://repairhelpcenter.blogspot.com/2011/11/how-to-test-and-replace-fuel-injectors.html
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How to Replace a Fuel Injector
http://schematicsdiagram.blogspot.com/2011/07/how-to-replace-fuel-injector.html
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Engine misses and truck jumps? Hard to down shift? Issue with high gear only? http://technoanswers.blogspot.in/2012/02/engine-miss-and-truck-jumps-hard-to.html

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Bad miss at idle?

http://technoanswers.blogspot.com/2012/01/bad-miss-at-idle.html

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While stop engine idles like cylinder missing?

http://schematicsdiagram.blogspot.com/2012/01/while-stop-engine-idles-like-cylinder.html

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Engine Misfire codes for car?

http://schematicsdiagram.blogspot.com/2011/12/engine-misfire-codes-on-chevrolet.html
Engine Misfire codes?

http://schematicsdiagram.blogspot.com/2011/12/engine-misfire-codes-on-chevrolet.html

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Misfire on cylinder 4?

http://schematicsdiagram.blogspot.com/2011/12/misfire-on-cylinder-4.html

-----------
Oil on spark plugs and car misfires?

http://technoanswers.blogspot.in/2012/02/oil-on-spark-plugs-and-car-misfires.html

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This will help.

Thanks.

Hello your po135 is o2 sensor bank 1 your po141 is O2 sensor bank 1 sensor 2 and your pO300 is random multiple cylinder misfire these problems are your oxygen sensors and engine misfire pO300 is you engine missing o2 sensors are switches in the exhaust system the engine misfires are the engines cylinders missing.

Barring any mechanical issues you most likely have a failed injector.

do you know for sure its the injectors?

i have a 2001 chevy z-71 5.3L. I keep getting a random/multiple misfire code for cylinder 1 . I have replaced plugs, wires, coil pack(only on #1 cylinder)., and fuel pump. I still keep getting the cylinder 1 misfire code. I put truck on a scanner and watched the cylinders. # 1 misfires at idle but quickly stops misfiring at around 1000 rpms. you can here the engine miss at idle but truck runs great on road . anyone else ever had this problem?