Missfireing started missfireing sudenly whilst driveing, replaced centre muffler, leads, plugs

I would say you need to have your fuel system looked at.

Engine is under max load in the situations you describe, so any weakness in spark or low fuel prssure can cause this, even a weak ignition module.

misfires can come from faulty injectors, low fuel pressure in the manifold. timing , blocked exhaust. faulty o2 sensor, leaking inlet manifold gaskets, faulty valves (burnt) It is not always plugs and leads. Have a fault code reading done.

Throttle position sensor, check that, or fuel pump/filter

I'm assuming you have a petrol fuelled car, as diesels do not have spark plugs.

Find the distributor cap leading off the distributor - it should look a little like this: http://www.google.com/images?um=1&hl=en&safe=off&client=firefox-a&rls=org.mozilla:en-GB:official&biw=1920&bih=895&tbs=isch:1&aq=f&aqi=g8g-m1&oq=&q=distributor%20cap

there should be 5 leads trailing from the cap - the lead in the centre leads to the "coil", the other 4 leads go to the spark plugs. There should only be 4 as the Mk1 was only made as a 4 cylinder engine.

Pull off the leads (though not whilst the engine is running as you'll electrocute yourself) and the spark plugs will be revealed.

if engine is running without missfire check catyletic converter for plugging also very rich running will cause exhaust to glow but will cause alot of black smoke from tail pipe I dont reccomend driving vehicle till exhaust or rich running is fixed can lead to engine failure

Hi,

Cleaning plugs is not enough you will have to replace them. Ensure that they are the correct type of spark plug for the engine also, Don't try and skimp to save money because it will cost you alot more further down the track if the incorrect plugs are fitted. Get your High Tension Leads(Spark plug leads) checked as well,
Check that your air filter is clean also, if not replace this if it hasn't been done recently....last 10,000 km.

Another thing to have checked as well is the Oxygen sensor this maybe faulty.
And lastly have your cold start tempreture sensor checked this maybe faulty. Start with the plugs first then work your way through it. Hope this helps, let me know how you get on.

Jason

you need to clear the computer out from the missfire that you created when you first started

Hi ,
These cars have various faults with the engine management systems,when you have eliminated all the basics such as spark plugs,air leaks ,vacumn leaks you need to plug into the car and read the live data from the engine while it is running,a good place to start is the pencill coils and the Mass air flow meter as these are more common and relatively cheap,do not use cheap import parts use OE it pays in the end.

If it is missfireing it wasn't your starter coils for a start. A reason your car will missfire is the timing is out. If it starts and runs your timing maybe a 1/2 a degree out and needs adjusting. It may also be one or more of your ignition leads (from spark plug to coils). Easy way to tell is with a timing light just plug leads in one at a time and start your car if timing lamp doesnot light or lights only as missfires change your leads, check your timing also while you are plugged into number 1 spark plug put timing light onto crank shaft pully should light up as a white dot goes past (bottom pully wheel). If you don't have access to timing light you can manually do it just take number one spark plug out with a small but longish screwdriver(careful not to dint or scratch piston head) crank motor by hand useing bottom pully till number one pot is to the top and look at bottom pully if white dot not at top crank motor till pot comes up second time and check pully wheel again. If still dot not on top your timing is out and you need to adjust it. If you find it to be your timing leave me message and tell me if fuel injected or carbureted and if you have magneto or distributer and I will try to help you