This is actually fairly easy. I just did it myself, but for cylinder 2. You need to get a new cylinder which will cost about $50 from Schucks. While you're at it get 6 new spark plugs.
Pop off the black plastic cover (both parts of cover) under the hood that's held down by 5 or 6 hex screws. Under there you will find the 6 cylinders. They should be labeled, but if not they go from #1-6 working from left to right, if you are facing the engine.
Simply unscrew the bolt that holds down the #4 cylinder, disconnect the wiring, replace with your new one, change the spark plug and then put it back on. That's it. I went ahead and replaced all my spark plugs while I was there. Dont forget to disconnect the battery though....it's in the trunk.
Worked for me and now she runs like a champ again.
Good luck.
start with wires
Take it to a garage.
1: Replace the injector. 2: If still misfiring, replace the engine.
How to fix a 1991 940 turbo 4 cylinder Volvo to stop running when traveling down the freeway
First thing to do is replace the plugs and wires if you have not done so. It you have or if replacing them does not fix the problem then have a compression test run.
it can be if you keep driving your car like that. could end up buying a new engine.. it could be a crack cylinder FIX ASAP!!
If cylinder 3 on a Ford Explorer is misfiring, it might be possible to fix it by changing the coil pack for that cylinder. The spark plug might also need to be taken out and re-gapped or replaced. If neither of these options work, the spark plug wire can be checked.
The exact cost to fix an engine cylinder misfire on a 2000 Mercury Mystique will depend on the exact type of engine it has, but can cost around $1,000.
1) Have vehicle scanned to determine which cylinder is misfiring 2) Does vehicle have C.O.P. (coil on plug)? usually a bad ignition coil on that cylinder 3) Remove spark plug from that cylinder and do a compression test to determine if problem is internal to the engine (bad valve or ring).
Physical damage to a cylinder is seldom repaired. More often the motor is replaced.
firewall 4 - 8 3 - 7 2 - 6 1 - 5 front
The only way to fix the Volvo-503 code is to take it to the dealership and have them fix it for you.