Ok so I'm a 740 guy. no problem to big, however my S40 I am lost in the woods. Drove the s40 home, running fine. Did have a o2 sensor code interment. Turned off car and never would start again. 210k miles timing belt not due for 20k more.
So I started checking. Codes read a misfire. Tried a known set of coil packs, starting fluid nothing. Checked fuel pump, could hear it run, 45 lbs cranking pressure. No fire nothing cranking would blubber once then nothing.
Ok put old coil packs back, close it up to go to shop, BAM it fires right up. Runs down the street good and smooth. Now I'm really worried.
Anyone have any insights??? It would do nothing then starts as though nothing wrong.
Any help GREATLY appreciated!!!
Had this listed in the wrong place. Reposting
Thanks to all

 

At least it cranks... ok give us all the codes

 

Thank you for the reply.
The current codes are 302 304 & 351. Have not had the 351 code before. It did start up this morning no problems. Could this be interment connection or ground problems??

 

P0351 are COP related and 302 + 302 are misfire so I would change out the Spark Plug Wires (you have 2?) and the COP rubber boots (you have 2?) right ?

 

The wires are Bougicord and were replaced not that long ago. I'm happy to replace all if that will give me back confidence.

 

a common problem area is the connectors to the coils. do you see any cracks in the plastic or poor contact? that would explain the 351 code...

 

I went ahead and purchased wires and plugs. Will replace tomorrow am. The connectors are not great. The plastic that surrounds the metal connector deteriorates. I have found that a piece of vacuum hose cut the right length makes the connector work. I would like to replace the connectors, does anyone know where the connectors could be found.
Thanks to all will update results of new parts.

 

AliExpress has tons of different connectors for cars

 

If your connectors to the coils are rotted or the green and red wires are starting to pull lose, I recommend this website for replacement connectors and wires, was skeptical at first but arrived in two days and came beautifully packed and a nice instruction pamphlet. Hope this helps!!


Dave's Volvo Engine Wire Harness Page - 960 and S90

 

Just a follow up. Ordered the wire harness from Dave's. New wires, plugs and cleaned up the harness across the top of the engine. Starts and runs perfect. Thanks to all who helped, back on the road again.