Looking for ideas into what I should check. It's a 2.4 low pressure turbo. Year is 2004. 90000 miles.

 

Are you certain you put the coils back in the holes they came out of? Many times my techs would write the cyl # on the coils before removal. Yes it's usually hard to get them mixed up.

If it's running rough you could disconnect each injector to possibly figure out what cylinder it's not running on. And focus on why for that one cylinder.

 

I appreciate your advice. Thanks. The coils and plugs are new. Does that make a difference as to coil/plug position when they're the same? If so, how would I sort that out? (I've checked for vacuum leaks, cleaned the MAF with compressed air, made sure these plugs and coils are the right ones for the car and 2.4t engine. The air filter is new.) What are your thoughts?

 

The coils and plugs are all the same - the wiring to each coil is specific. Each coil will have 4 wires in the plug. 3 wires, Black (sb) red and yellow are common to each coil. The other wire in each plug goes to a specific cylinder. #1 yellow w/ black stripe, #2 orange w/ black stripe, #3 blue w/ black stripe, #4 grey or green w/ black stripe and #5 yellow w/ red stripe. As I mentioned it's difficult to swap coil wiring harnesses - the wires are usually not long enough. Did you check the spark plug gap before you put them in?

If you have a 2004 c70 coupe or convertible (the 99-04 body style) your engine uses the known to fail Magnetti Maerilli (sp) throttle module. Volvo stopped using that part (probably due to short life and high failure rate) on all the other cars in 2002. Have you scanned the car to see if there are any self diagnostic codes? Those codes could point you in the right direction. And a bad throttle can certainly cause poor running. How old is yours? (look for throttle modules at xemodex.com. A new throttle module requires a software download using VIDA to make it work - xemodex can "program" a replacement in Canada before it is shipped to you.

 

Wow! Thank you. It is the 2004. It was throwing codes. I will run the OBD2 again to see what is there. If I remember right, and this was a few weeks ago, the codes were about misfires at the top and bottom of the coils. I need to verify that again. Like I wrote before, thank you again. I will be in touch.. Douglas