Got a Oscilloscope or or a Logic probe? Probe the signal on each injector.
If it was wiring I would expect misfires also.
A fresh set of remanufactured injectors is not a bad idea, US$50 - US$60 per set.

Check valve in Volvo assembly 30757307 (Evap System Hose Assembly) . The assembly is ~$110.00. The best and probably the only way to get just the check valve is a salvage yard or JB Plastic Weld the one you have back together. https://www.fcpeuro.com/public/assets/products/260530/large/data.?1496495...

Cylinder #1 is closest to the timing belt. From there it is 1, 2, 3, 4. You think you have a lean misfire on all cylinders ... Air leaks or low fuel pressure. I would get cylinder #4 to Top Dead center on the compression stroke. Then flood it with Seafoam and let it soak. It could be as simple as ca...

Stage 0 on this 204k mile new-to-me, slightly O'Reilly'd and Auto Zoned up Texas 855R. That'll be a satisfying paint restoration! Somebody posted on here recently about bringing tomato soup red paint back to original beauty and it was nothing short of spectacular. Volvo 850 Red Paint Restoration. B...

I used Akebono ceramics which were great -- no squeal and no dust -- but they seemed to not grab as well when cold compared to the Volvo pads. Metallic is for performance. Ceramic is for cosmetics. Ceramics need to be warmed before you get the superior braking, not an issue in warmer climates. If y...

Optional location for a PCV breather hose. Like the optional location for the oil filler.
If it is not leaking leave it alone. If you want it to look better cut it off flat.

As for why somebody would do that. We have seen this one time before and nobody has a clue.

That is not a Volvo Modular Engine (VME). It is the next generation after VME, Volvo Engine Architecture (VEA). The camshaft alignment marks are on the rear of the camshafts. The VVTs are preloaded and aligned using tool 9997497. 1. Align the crankshaft to the block. 2. Align the camshafts to the cy...

With the camshaft lock tool. It goes in the slots on the back of the cams. The slots are offset so there is no way to get it wrong. That will align the cams to the head.

Go to eBay. There are mail-in services where you send the immobilizer. They program the key if you have one or a new key(s). Then mail it all back to you. About $200 here in the U.S.

Watch the product locations as you go through the listings. You might find one local.

I thought id check here to see if anyone had a VIDA Dice workaround or a plug n play OBDII solution. If you have a DiCE unit. Yagger in Belarus has done key programming over the internet. You would need to get the details from him. He probably can provide a mail-in service but, I don't know if he d...