Rite so lads two days ago the passat started misfiring...so i checked the leads lead 4 was broke inside and lead 3 wasnt giving a strong spark so i changed the boath of them running fine until last nyt started doin it again...so today i checked the spark plugs and thay look ok and fairly new...its giving a stong spark on all 4 cylinders...but its spluttering between 1000 and 2500rpm...takes of then and hits a few flat spots up through the revs???can any1 shine a light on this??

check that the cam shaft is turning ( broken timing belt/chain will not allow position sensors to give spark). Check that the immobiliser is operational. have the fault codes read

Hi. You have misfires on cylinders 4, 5 and 6. If there are no faults on cylinder 1, 2 and 3 then I would check the power to the left bank injectors. Also check spark plugs and ht leads. If there are running issues then this should be an easy fix. If the faults are very intermitant then it can be a bit tricky to isolate.

could be plugs, leads or even leads on the wrong plugs. try swopping a lead from a good cylinder and see if it fires then if it does, purchase a new set of leads. swop over leads on 3 and 4. a new set of plugs always helps. check for shorts (start engine when dark and look for any sparks from leads that you cant see in daylight). If none of this helps then check compression on cylinders 3 and 4, if low pressure check valve clearance, if valve clearance ok then it could be burnt valves or head gasket problem. Are you losing water? is water oily? Check the easy stuff first

P0303....Cylinder 3 Misfire Detected

P0304....Cylinder 4 Misfire Detected

sounds like a new set of HT leads and plugs wouldnt go amiss(fire wires) weird name that fire wires HT stands for high tension leads in proper english .

Try to check the injector if it is giving petrol.

code 300 random cylinder misfire, code 303 cylinder 3 misfire detected code 304 cylinder 4 misfire detected. check the spark plug wires 3 and 4 inline tester for constant fire. also check the spark plugs , clean and reset the gap if necessary. if all is good check the coil terminals for corrosion. if this is all correct then check the coil with a ohm meter for primary resistance by attaching the leads to the positive and negative terminals. then check the secondary resistance by hooking one of the ohmmeter leads to the center terminal and the other lead to one of the outer terminals the resistance for primary test should be 0.95 to 1.20 ohms and the resistance on the secondary side should be 11,300 to13,300 ohms. hope this will help!!!

hey
id say no:2 cylinder isnt firing rite, maybe due to a faulty ignition lead or spark plug. id say get new spark plugs.
good luck

Hi if your car is petrol then you need to check that the plugs work try swapping them round with 1 and 2 if they work you then need to check the leads you can do this by taking the plugs out of 3 and for and then connect them to the spark plug leads then rest them so they are earthing out in the engine bay( you need to make sure its just the end of the spark plug resting onto metal then turn the engine over and you should see if the plugs are sparking it should be bright and regular spark. (its better to do this in the dark ) before you remove the plugs wait till its dark then with the bonnet up get someone to turn the car over and nif their are any sparks coming from the leads on 3 and 4 if their is then the leads need replacing.

IF no spark at plug and no short on the leads then you need to check the distributer this is where all the plug leads go into check this for any crack when you remove it.

Once removed look inside at the four contacts make sure they are clean and free from contaminents such as oil as their is a seal just behind this might have gone you can use sand paper to clean the terminals to ensure the electric can be sent from the rotary arm to the distributer so check its clean als use fine sand paper on the end of the rotary arm then refit and check for sparks again if its now sparking then give the car a try.

If you are getting a spark at all four of the plugs and the spark is good all round then the only problem you could have would be with the head gasket.
Are you sure the leads are fitted correct way round before you start any work.

If you have checked all leads and you have good spark then it can only be the head gasket this can be tested by using a sniff test or a compression tester these can both be brought from car spares shops but prices can vary.

Let me know how you get on or if you need further assistance ok

I have exactly the same problem and codes you listed on my 2000 Camry 4 cyl. I replaced the plugs which had no effect. My friend mechanic said the problem is deffinitely the wires and I could also need to replace the coil pack.

Hi

If the coolant temperature sensor is of the 4 wire type then these are a common failure on VW's.

Regards

Geordie