5 replies to this topic

[HepS70]

I am currently having the problem of mutiple cylinder misfire. Code P0300. When reading all of the post when you search, misfire, nobody ever says if they solved the problem. I have a 98 S70 T5 and About a month ago I put on a new cap, rotor, Magnecor Wires, and Iridium Plugs. So tonight I replaced the plugs with the stock ones I took out. I checked the gap and made them .28. Went out driving and sure enough the CEL came back on. Can someone please help me out on this one. Someone who figured ourt what the problem was. Anyone had problems with Magnecor Spark Plug Wires? Please let me know...
Thanks,
Chris

[yangotang]

Sometimes weak or faulty connections in spark plug wires can cause misfires.

Have you the old spark plug wires? You may want to put those in and see what happens to see if you can eliminate one more variable.

[HepS70]

I will try that and see what happenes. couldn't hurt to try it. It seems like all of the other posts about misfires are all s70's and have Magnecor wires. I will post my results.

[ed850]

Replaced the origonal wires,cap and rotor on my 98 S70 with 117,000 miles on it with Volvo parts and had no problems.I think the wire set was about $90.Something to be said for OEM

[RiddickJordan]

hey, i just got over this problem. min ewas a bit different though b/c it was isolated to the 3rd cylinder and it happened after i had messed with the boost. The problem was apparently with the crappy NGK E3 spark plugs that i had installed 2 months earlier. We took them out and they were all black and nasty already, looked like they had been in there for years! I put in NGK IX iridium plugs and it solved the problem for me. I originally tried running 15 psi, but for now im keeping it at 13psi untill i get new wires. Im pretty sure im going to get Nology wires due to thier extreme badassness.

since u already have a new ignition system, u might wanna try your injectors. If u go to advance you can but some Lucas Injector cleaner which works really well. If none of that solves it, u may have a leak around ur injectors which can be diagnosed my spraying some starter fluid around them while the car is on.....if the engine revs, then u have a leak, probably an o-ring or something.

thats just some of the tips i was givin when trying to fix mine. carefull with that starter fluid though!

o yea, carb choke cleaner while ur at it.

[MrWinkey]

I am currently having the problem of mutiple cylinder misfire. Code P0300. When reading all of the post when you search, misfire, nobody ever says if they solved the problem. I have a 98 S70 T5 and About a month ago I put on a new cap, rotor, Magnecor Wires, and Iridium Plugs. So tonight I replaced the plugs with the stock ones I took out. I checked the gap and made them .28. Went out driving and sure enough the CEL came back on. Can someone please help me out on this one. Someone who figured ourt what the problem was. Anyone had problems with Magnecor Spark Plug Wires? Please let me know...
Thanks,
Chris

Did you use OEM cap and rotor?...If not I would suggest replacing them with O.E stuff....as for the plugs you should never have touched the gap on the plats or iridiums just a visual inspection and I recommend OE as well but NGK's are fine. I doubt it's in the magnacore wires but it is possible. There really is no need for the heavier wires?(in my opinion)