V70XC 1998 Multiple Misfire Codes

kennedcx · Post by **kennedcx** » 02 Jan 2010, 11:32

Hey guys, I've been looking through the threads and most of the reports of multiple misfires include items I've already done. So here is what's happening.

I have a 98 Volvo V70 XC with the 2.4L engine. It has 225,000 miles on it. We've been fighting multiple misfire codes P0300, P0302, P0303 and P0305. We've had a Certified mechanic check out the compression on the cylinders and he said the rings are worn but it still gets good compression.We've replaced the following components (with OEM Vovlo parts) so far:

Spark Plugs
Plug Wires
Distributor Cap
Rotor
Ignition Coil

At this point I'm thinking about taking it to the Volvo Dealership and let them do a diagnostic because we're trying to sell the car to be able to move but everyone is worried about this misfiring issue. If you drive the car, it's not missing or vibrating at all. You can floor it and it doesn't hit a lick. Someone who looked at buying it said he thought it might be a distributor causing the misfire. I could sure appreciate some insight into my Volvo riddle. I apologize if this is already talked about in another thread, just point me there cause I've been searching and can't find any that suggest replacing more parts that I've already replaced.

Post by **Pauloil** » 02 Jan 2010, 19:46

check your B+ cable, from batt pos to fusebox.

Post by **jblackburn** » 02 Jan 2010, 21:19

I'm thinking, though the car may not be showing a code for it, that you've actually got a cam position sensor issue, since you've tried all the ignition parts. Have you ever had any hard cranking issues?

9394volvo850s · Post by **9394volvo850s** » 02 Jan 2010, 21:27

Make sure that your plug gap is set to .028"!!! Mine was set at .034 and i had a mutiple misfire sometimes under acceleration. now its at .028 and it runs like hot butter on 20psi.

Post by **shiloh51933** » 25 Apr 2016, 18:04

jblackburn wrote:I'm thinking, though the car may not be showing a code for it, that you've actually got a cam position sensor issue, since you've tried all the ignition parts. Have you ever had any hard cranking issues?

I know this is old but sounds like my issue, sputter at stop in drive or park. There is some throttle response loss, meaning G not as peppy but goes without backfire when you give it throttle. New plugs, wires, cap/rotor, gd FP, can't find any vacuum issues, it's getting spark, tried fuel additives/cleaners. Why wouldn't CEL light up for the CAM sensor though??

Post by **erikv11** » 26 Apr 2016, 08:45

Shiloh, did you try unplugging the MAF, then starting it up and going for a drive? MAF doesn't usually cause misfires but it can, and it is free to try.

Post by **sleddriver** » 26 Apr 2016, 10:45

I wonder if it could be the lead from the coil to distributor, being too close to the crank position sensor, just below the distributor? Seem to recall reading somewhere that this can cause problems. You might want to temporarily route it on top, over the air filter box, to get it as far as possible and see if the misfire codes cease.

Post by **erikv11** » 26 Apr 2016, 13:29

That's a great idea to check.