just purchased 05XC90 2.5, 230xxx Topic is solved

[aaron1611]

I won’t be back in town until later next week but will PM member. Not too worried about siren module. MAF has been cleaned and all vacuum lines nearby are good. No unmetered air getting in. No dip stick to check tranny fluid unless I’m missing something. I’m fairly confident it’s either pump or PEM. Will post back once in town.

[SuperHerman]

Transmission dip stick: viewtopic.php?t=71533

[aaron1611]

Nice. Will check fluid when I get back in town. Bizarre that my Bosch PEM part number does not show up online. Mine is 30636431. Can I purchase any PEM that fits my year and model despite it being a different part number?

[aaron1611]

so, just to follow up on this post now that I've installed the new PEM. I also installed two very strong magnets to the bottom of gas tank. We put almost 900 miles on the Volvo in the last 10 days with the new PEM installed and 3 times we felt the hesitation during acceleration over this period of highway driving at speeds around 70-75 mph but it threw the CEL after about 10 miles into our trip. I'm a bit confused now as to why this problem isn't consistent and what to do next. No other real noticeable problems driving the Volvo. I pulled codes today

212C long term fuel trim, bank 1 signal too high
21ED same as above
2900 fuel pressure-faulty signal-this code cleared once I replaced the fuel pressure sensor but it's back again
290D fuel pressure signal too low
430C fuel tank system-missing filler cap-will order new cap this week
434C fuel tank minor leak
439C fuel tank major leak

I'm wondering if the Purge Valve is faulty despite no code for it. Not prepared to replace fuel pump yet since the hesitation was an annoyance that resolved itself by letting off the accelerator. No stalling or anything either. Bizarre.

[SuperHerman]

Have you tried pulling the purge valve and then checking performance and codes? If it is working and then disconnected it should throw a code.

My experience if one keeps getting the same codes saying you have fuel pressure issues - then you have fuel pressure issues. You should do a fuel pressure test.

I am battling an overboost on my XC90 T6 and have narrowed it down to sticking waste gate flaps. Symptoms, other than actual codes, are similar to yours. Have you checked the action on your turbo actuator?

[aaron1611]

well, digging a bit deeper on the fuel pump duty cycle should be in the mid 30% at idle and mine are consistently in the low 50%. I'll rent the external gauge to check pressure at the rail but I guess replacing fuel pump is my next project since I'm still getting code 2900 with new FPS.

[aaron1611]

what about rebuilding the fuel injectors? I don't know the history of them but with 230K on the odom they are probably due.

[SuperHerman]

What is actually rebuilt is limited. The actual injector is not touched. I would either source new ones or used ones with lower miles (and rebuild those if required). Honestly, if they look good I would save that project for later, once the vehicle is sorted.

[abscate]

Find shockwave's awesome thread about troubleshooting intermittent fuel delivery, pumps, PEMS, etc.

His root cause was a kinked fuel delivery line in the tank.

[aaron1611]

I did read shockwave's very long but great read. Ordered the pump but will check for kinks prior to doing the switch.