2004 XC70 Misfire on cylinder #4, wrong spark plugs

Post by **jonesg** » 14 Nov 2016, 08:06

All plugs are not equal despite the cross referencing, discovered that when working with marine outboards.
Certain engines are designed with a plug in mind.

Post by **abscate** » 14 Nov 2016, 08:24

It's never the ECM......

Post by **chrism** » 14 Nov 2016, 09:40

Glad to hear it's all better now. Were you running NGK copper cores?

I'm curious, what book calls out Bosch dbl platinum iridium plugs? I've never seen that specified.

Post by **shiloh51933** » 14 Nov 2016, 14:19

chrism wrote:Glad to hear it's all better now. Were you running NGK copper cores?

I'm curious, what book calls out Bosch dbl platinum iridium plugs? I've never seen that specified.

The NGK-BKR6EGP is the plugs I had in her. I installed them after replacing all the coil packs, TB,TB tensioner, TB idler pulley, WP, Coolant, TB cover clips and variable cam sprocket hub plug.
I was getting spark but I'm thinking there was too much resistance at the plugs. Here's a pic of spec plugs from my repair manual for V70 2000-2007 & S80 1998-2006.

Post by **shiloh51933** » 17 Dec 2016, 08:21

abscate wrote:It's never the ECM......

Hey abscate, got a question and hoping you or someone can suggest something. This random misfiring has come back slightly. It acted up briefly missing recorded on 4 cylinders then just went away minute later on its own and now is running perfectly.
Only other code besides misfiring codes is a Volvo enhances factory code 928C, which is what? CEM?

Post by **abscate** » 17 Dec 2016, 17:58

Its a communication problem with CEM or the steering module according to my reference. I don't think that is your misfire problem

Post by **shiloh51933** » 18 Dec 2016, 08:22

abscate wrote:Its a communication problem with CEM or the steering module according to my reference. I don't think that is your misfire problem

Thank you for your response. This car is really starting to annoy me, this is like 3rd time in last year with random misfire issues. A year it happened immediately after doing Tbelt, WP, Tensioner, idler pulley, VVT cam plug. It was running good before I removed Tbelt and on initial start up bad random miss. Ended up having 3 faulty coil packs, I thought I screwed up VVT cams resetting procedure initially but for whatever reason those coil packs decided to call it quits. When I replaced all 5 of the coil packs I decided to replace the spark plugs, Why not I'm gonna be in there anyway. To my surprise 6 months later the NGK plugs that were spec for my wife's 04 XC70 were causing misfire issues. I replaced with the factory Bosch FR7DPP plugs that the book recommends.
Sorry for the rant, I'll go through her again to see if I can find something. It ran good today for a couple hours but i don't want this to act again while my wife is out driving

2004 XC70 Misfire on cylinder #4, wrong spark plugs

Re: 2004 XC70 Misfire on cylinder #4,