Misfire :/

kurai · Post by **kurai** » 24 Feb 2010, 00:00

A few days ago my car started acting funny.
It will idle ok in park, but as soon as I shift it into gear it will shake pretty bad. It will also accelerate really rough until it hits about 3000 rpms then it will settle down until i have to stop again. It also lost a lot of power.
I went and got the codes read today and they told me that I have a misfire in cylinder 4 and 5. Before i spend forever trying to figure out whats causing this or how to fix it does anyone have any suggestions?
It doesn't make much sense to me because it was running perfectly fine before.
Any help would be greatly appreciated! =)

Post by **IVIUSTANG** » 24 Feb 2010, 00:36

Plugs, wires, cap and rotor, ignition module.

Spark plug wires are my first guess. Check your plugs for gap and wear before you throw new wires at it. Sounds similar to a few other instances of misfires I have dealt with. I will also note, in every case it seemed to be cylinders 4 or 5 that had the misfire, which is odd to me.

- Jesse

kurai · Post by **kurai** » 24 Feb 2010, 00:43

thanks.. I'll check the plugs. But it seems unlikely because its got brand new plugs and wires as of 6000 miles ago...
I was thinking maybe just dirty injectors and maybe the fuel filter because varies on how severely it acts up.

Post by **IVIUSTANG** » 24 Feb 2010, 10:28

What brand of plugs and wires?

- Jesse

kurai · Post by **kurai** » 25 Feb 2010, 12:12

I dont remember... I can check when i go home bosch i think. I know we got the most expensive ones and a brand new distributer cap

Post by **jblackburn** » 25 Feb 2010, 12:28

If you used Bosch plugs with multiple prongs (especially the Platinum-4's that have worked fine in every other car I've ever used them in), Volvos get very angry at these. Some say Iridium plugs work fine, and I successfully used Autolite Platinum single-prongs in mine for 2 years. Most people choose to go with the cheap Bosch Copper plugs though, which work just fine.

Post by **Ozark Lee** » 25 Feb 2010, 17:35

+1 on what Jason said,

These cars just hate the Platinum +II and +IV plugs. You can't gap them. Go get a set of Bosch Super Coppers, they used to be part number FR7DC but Bosch recently changed the numbering system. Out of the box they will be gapped at 0.035 to 0.040, you need to knock that down to 0.028. They are a little bit tough to find but NAPA stocks them. The good news is that they only cost around $1.00 each. They wear out kinda quickly, I change mine every 30k miles or so, but for $5.00 who cares.

...Lee

kurai · Post by **kurai** » 02 Mar 2010, 01:43

Checked the plugs... They were bosch platinum single prong... But i changed them anyway to champion copper plugs gapped at .028
Didnt do anything.. Also I noticed that my check engine light is flashing

Post by **boosted5cyl** » 02 Mar 2010, 12:16

Its flashing because of the misfires. You need to pull the codes and find out what codes are in there. Maybe the actual HT coil is going south. You can test the resistance with a meter, somebody else might be able to chime in on what readings you should be seeing.

kurai · Post by **kurai** » 06 Mar 2010, 13:26

Got sick of messing with it and brought it to the shop.
Turns out I have a burnt valve and no compression in cylinder 5