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No one seems to be able to correctly diagnose this problem. I have had the following parts replaced: fuel filter, cam sync. sensor, spark plugs, ignition coil, spark plug wires, air filter, and the fuel injectors cleaned, nothing fixed the problem. Engine light did come on (flashing light) when the ignition coil was replaced. Had to take new coil off and put old one back on, the car actually ran worse with the new coil on it, we did this twice, second time engine light came on (did not flash this time just stayed on), so put old coil back on again, codes read that it was misfiring on #4 & #6. Car also bucks sometimes while idleing. Gas mileage is terrible. Can anyone tell me what is wrong? Car has about 74K miles.
Hi Smartwrench1, the injectors were cleaned by an auto shop and they used some kind of chemical kit to do this.Hi Smartwrench1, the injectors were cleaned by an auto shop and they used some kind of chemical kit to do this.
Hi Cheap Labour, I don't believe the mechanic has checked for a vac leak yet, he is going to take another look at it this week and I will suggest to him what you said about the O rings. I was doing some more research myself on this and had come across the idea that it might be a vac leak, maybe even possibly some vac hoses???? Thank you for your input.Hi Cheap Labour, I don't believe the mechanic has checked for a vac leak yet, he is going to take another look at it this week and I will suggest to him what you said about the O rings. I was doing some more research myself on this and had come across the idea that it might be a vac leak, maybe even possibly some vac hoses????
Thank you for your input.
when you say fuel injectors were cleaned were they removed from car od did you have them chemical cleaner ran threw the fuel rail?when you say fuel injectors were cleaned were they removed from car od did you have them chemical cleaner ran threw the fuel rail?
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Sea foam the vacuum system vacuum in about 10oz seafoam using the brake booster line has larger hose to pour slowly into. Then shut car off for 20 minutes. Then restart under hood hold throttle steady at about 2500rpms look for smoke along the firewall if so u have a vacuum leak that's causing this phenomenon. Intake to the cylinder that is miss firing ad a vac leak. Even a small leak will throw off the crank position sensor every so often especially on cold damp mornings or very humid weather.
I have a 2001 Taurus with a misfire in #2, I've already replaced all the plugs, wires, and the coil. I did a professional fuel injector cleaning at a well-reputable shop, I then had that same shop spend a day and a half to diagnose it, and it turns out that it is a sticking valve in that cylinder causing the misfire, have them test the compression off and running to see if that's the issue.
Have your intake manifold o rings replaced. it is most likely that it would be a vac. leak. and the engine monitor cannot properly diasgnose this problem and having you replace 1000$ in parts and never find the problem.
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Kristen, Get car checked to see if there are any stored trouble codes. Have you had a complete tune up recently, may be time, including fuel injection cleaning.
The list for this issue is extensive, I will post links for you to check out. Diagnosing Misfires
misfire condition. The check engine light is blinking to tell you it detects multiple misfires. Go to your favorite local auto parts store and ask them to scan your auto for check engine codes. If nothing is seriously wrong, you may get away with just changing the oil, oil filter, air filter, fuel filter, spark plugs and adding some injector cleaner to the fuel tank. If you have other problems, the engine computer will have codes stored (besides misfire code) that will lead you in the right direction to diagnose them.
This car has coil packs which connect to each spark plug.the spark plugs sit deep under the top cover and need a special plug spanner to remove as the access is narrow and deep.
first check the condition of each plug....replace which the correct type ....make sure they are the correct gap...do not over tighten just a quarter turn after they bite.....run car engine .....if it still misfires then you need to replace the ht leads ....swop them with a new set.....if still misfires then it's the coil packs which are the most expensive part of replacement.i sourced mine on eBay.hope this is of help.as this is electronic ignition the misfire is most likely due to 1. Dirty plugs with incorrect gaps....2.faulty ht leads.... 3. Faulty coil packs....4. Incorrect timing.
Gear ratio does point to an internal transmission issue. The misfires can easily be diagnosed by swapping thing around and seeing if the code follows. For example misfire in cylinder number 1 & 2 swap coils to cylinder number 3 & 4 and if the code changes from P0301(2) to P 0303(4) you know you need coils.
Hello The
Engine and Automatic Transmission (not applicable to manual
transmissions) in this vehicles drive train are fully
electronically controlled by a computer called the PCM and TCM (Power
Train Control Module, Transmission Control Module). When a problem
like this or other drive-ability related problems occurs the computer
stores a record of the problem (there are of course some exceptions
to this, like the fuel pump, engine coolant temperature sensor and
MAF sensor for instance) in the form of a fault code in its memory,
to read these fault codes you must have the systems memory scanned
with a special tool. Once the fault code(s) are read you then must
perform the appropriate diagnostic testing to find and resolve the
problem(s)DO NOT REPLACE ANY PARTS UNTIL A TRAINED
TECHNICAIN HAS DIAGNOSED THE PROBLEM TO AVOID SPENDING YOUR HARD
EARNED MONEY ON PARTS THAT MAY NOT CORRECT THE PROBLEM. Also always
check fuel pressure for correct spec for your make and engine type.
Misfires must be diagnosed. As you can see, randomly changing parts in an attempt to diagnose the problem can be vert COSTLY. Besides all the parts that you have allready replaced, there could be a problem with the fuel injectors, there could be cylinder compression problems caused by a number of possible causes including bent/burnt valves, broken valve springs, or a head gasket blown between cylinders. There could be timing problems due to erratic knock sensor input. Fuel shutoff due to throttle position sensor "dropout". "Random" misfires (which is what a code P0300 code is) can even be caused by something as crazy as a vacuum brake booster leaking and creating a large vacuum leak....the list goes on and on....
It is easiest and most cost effective way to diagnose this type of problem is by using a scan tool and looking at all of the engine data and/or taking a "snap-shot" of the data when the problem is occuring. This way, you can tell which parts of the engine control system are being affected so those areas can be inspected for possible failures. The first step is to isolate the causing SYSTEM. So far, you have replaced parts for the fuel system, the ignition system and the EGR system....
HAVE VECHICLE CODE SCAN AT ANY AUTO PARTS FOR FREE SOUND LIKE FAULTY EGR VALVE.SEVERE CYLINDER MISFIRE BAD SPARK PLUGS OR BAD COILS. COULD HAVE LEAN FUEL MISFIRE CLOGGED FUEL FILTER WEAK FUEL PUMP, FAULTY MASS AIR FLOW SENSOR.
check at the parts store and have them show you what it looks like.also follow fuel lines under car to the engine.seems to me the filter is i engine compartment..im sure you have a reason you want to replace..maybe the correct question is hesitation on acceleration, no power,ect....it is easier to figure out the problem before the repair. or spent 500 bucks on car and still does the same thing
SOUND LIKE SEVERE ENGINE MISFIRE HAVE VAN SCANNED AUTO ZONE WILL DO IT FOR FREE .BUT MAKE SURE FUEL FILTER NOT STOPPED UP MAKE SURE PLUGS AND WIRES IN GOOD SHAPE.FILL FUEL TANK UP.PUT A BOTTLE FUEL INJECTOR CLEAN IN FUEL TANK.TO CLEAN OUT FUEL INJECTORS WHILE YOU DRIVING THE VECHICLE.ALSO BAD COIL OR COILS WILL CAUSE ENGINE TO MISFIRE SHAKE.
Hi Smartwrench1, the injectors were cleaned by an auto shop and they used some kind of chemical kit to do this.
Hi Cheap Labour, I don't believe the mechanic has checked for a vac leak yet, he is going to take another look at it this week and I will suggest to him what you said about the O rings. I was doing some more research myself on this and had come across the idea that it might be a vac leak, maybe even possibly some vac hoses????
Thank you for your input.
when you say fuel injectors were cleaned were they removed from car od did you have them chemical cleaner ran threw the fuel rail?
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