Not sure if we got a death sentence on '07 V6 XC90... fuel pump, prop shaft, 2-3 cats + more?

[GreenMagicMan]

Thanks, yes, I might in fact do a little mix and match of parts. As, well, all 3 vehicles right now are having some pretty big troubles.
Will post back what I can discover.

[pgill]

If you are really ambitious you could swap the fuel pressure sending unit.

Note: expect some fuel to spray out as you disconnect (if the vehicle hasn't been driven for hours then the pressure should be minor)

The sensor is held in by one Torx screw and the O-ring

The location is shown by the arrow on the right in this sketch (the arrow is actually pointing at the wiring harness connector for the sensor)

[pgill]

Here is a link to the part

Its not expensive

https://www.fcpeuro.com/products/volvo- ... 38#fitment

[GreenMagicMan]

Blue Car (3.2L): disconnected the MAF today, end of story - no difference. Not great cold start, almost died had to give it throttle.

Silver Car (3.2L): disconnected the MAF today. And what do you know!??! It ran GREAT.
Huge noticeable difference on same loop on the flats and climbing major hills.
Ran like a champ disconnected, ran great up steep hill. Shut off engine, reconnected MAF and it instantly ran horrible on the re-start.
Bucking, and stumbling, misfiring - the flashing CEL came on. Ran 60 sec more to a roadside pull off, shut off car and reconnected the MAF.
Re-started and it ran like a superstar again (This time I climbed the car the entire way up Bethel Mtn. Pass summit).
Comparatively, the silver car runs with gobs of power and great compared to blue car. The blue felt like I was towing a battleship behind it, and couldn't basically exceed 30 mph up hill. WOT made no difference in speed / accel just more noise and the noise didn't sound good.
I had friend rev the throttle and looked under the blue car. No glowing cats to be seen, but the exhaust buckled under throttle noticeably under throttle and the exhaust pipes seemed restricted as best I could guess. The exhaust pipe gases exiting didn't seem to freely flow and match the throttle - as my best guess.
Could the cats really be plugged up and causing this?

I bought a used working PEM from the independent Volvo guy today for $125 with 90 day warranty. I'll likely put that in the blue car tomorrow.

Will try to clean both MAF tomorrow anyway and also on the V8 and probably my Honda Coupe for good measure while at it.

Only flaw was the cold starts with MAF disconnected weren't wonderful (low idle and needed throttle assistance), and the throttle input change for 1/2 second was abrupt / jerky and then throttle control would be super smooth. So, if cruising no throttle and then press the gas pedal it had a short quick hesitation but then was very linear and smooth after that little blip each time.

[GreenMagicMan]

By the way, the Silver car (3.2L 2007 model XC90) was throwing misfire codes: P0302, p0303, p0305, p0300 - been doing that awhile. Only this summer has it thrown a P0174 code - and I just looked that up and it's a common MAF error issue that can trigger that code!
Final code it was throwing July 20th was a P0455 so at some point I'll work on that little issue as well.
Will hope that cleaning MAF helps a lot, and if not buying a new one for this car.

[GreenMagicMan]

The "red car" is 2005 XC90 V8
Here's what it's doing:
P2407 Evap emissions sys leak detected, pump sensor circuit inter
P0435 eval erratic reference on face low flow
P0171 Sys too rich Bank 1
P0175 sys too rich on Bank 2
P0089 Fuel pressure regulator one performance
P0193 Fuel rail pressure sensor A circuit high

The "blue car":
2007 188K XC90 3.2L
misfire codes (abbreviated): 303, 304, 305, 306, 300
cats gone: 430, 420
AND THIS little stinker: P0190 Fuel pressure Sensor A circuit

[chitownV]

What car are you asking help for again? Trying to follow.

If it is the original 3.2 Inline 6 XC90, then pgill was directing you down the right road. The first steps are to ensure the fuel pressure sensor is not (reading) bad. This is easy to change and one of the more affordable parts. Then, once that is changed, it's good to see what comes up.

When working to diagnose at home there is a combination of looking at codes, changing known wear parts, then reassessing. I have some questions:

1. What is the history of the XC90 3.2 that you brought to the shop? Get a good baseline understanding and what lead up to this point. Simple example of why I ask: If it spent its life in the South, then it might not be cats or even a leaky cat, My reasoning, the use of salt in snow states can rust those (secondary) cats and exhaust pipes.
2. Does the engine choke at higher rpm when not on load (not going up a hill)? It should feel like it is choking if the cats are clogged, not just a misfire. The 3.2 has a lot of tech in the engine, including variable valve timing and cam switching. If these are slow or get affected in some way, it can cause mis-timing and less power with 'on-load' situations. These are some reasons to use good quality oil.
3. Let's stay focused on one vehicle at a time. Getting lost in all the different issues and XC90s.
4. Most people don't memorize error codes. So, if you post an error code, add what that is. You started to do that, but it was for a V8 and not for the I6 3.2 in which you started this thread.
5. What is the maintenance history of the 3.2? Are the fluids and filters changed? What fuel is being used and which brand?
6. Sometimes a drive shaft only needs the center bearing changed or the CV joint, and not the entire unit. So search that too
7. With so many Volvos you are looking after, as wanderdune suggested, good idea to get VIDA and the DICE for Volvo specific diagnostic software and testing

[GreenMagicMan]

Hi, thanks, yes the Inline 6 3.2L. We have 2 of those cars (blue and silver) and a red V8.
The silver one looks like it may be working well and either cleaning out or replacing the MAF should solve it's problems for now.

The blue 3.2L I'm focused on now.
We are going to get the fuel rail pressure sensor new part today and put it in tonight and see what happens. I checked the connector just now and it's super clean and well connected and the wiring to it looks fine.
I'm concerned maybe those cats are clogged perhaps and restricting exhaust flow as well.

[GreenMagicMan]

Problem with all 3 cars: completely unknown histories.
Red V8 and Silver 6 cyl cars were bought at Police auctions. No known history and maintenance unknown. Red car been in family 16 months, silver car in family for 6 months. Both have had a slew of issues. Some small and annoying, some medium bad.

[GreenMagicMan]

OK, thanks! Let's focus only on the "BLUE CAR" from now on on this thread. It's 2007 6 cyl 3.2L with approx 186,000 miles.
It was purchased about a year + ago from a used car dealer who said it was good car, but it seems it has not been so.

CODES:
Main code I'm concerned about is the P0190 code for "Fuel Rail Pressure Sensor A Circuit"
Has both 420 and 430 failed catalytic codes showing up and let's all assume the cats are destroyed from all the misfiring cylinders.
I'm either chopping them out and running the car outlaw style, or frankenfixing in someone's private junked Volvo cats, but ain't no way we're plowing $4000 - $5000 to replace 2-4 cats on this car at shop.

DIAGNOSTIC TOOL:
We want to get the VIDA DICE tool(s) but we have family member who has one we've wanted to buy who's been unresponsive about it. Reason we are waiting is I'm confused if they can be bought or 'activated' anymore....
I'm also a MAC only person, but we've located a new enough PC in the family to use. Any advice on the VIDA to get would be terrific (I WANT one!!)

MAINTENANCE:
Oil and filter changes? Well, this family doesn't really subscribe to the preventative maintenance thing. Everything here is generally 'reactive' not 'proactive'. It does get changed, but it's whatever Joe mechanic puts in the car. I've changed one of them myself. I think i put in 'dino' oil not full synthetic and whatever filter I could easily get.
With me not working since March due to coronavirus you'd think I'd have all sorts of time but feels like I've never been busier. Trying to knock problems as I can.

DRIVE SHAFT AWD: Good to know about that, thanks. The mechanic we took car to originally said he thought it could be the bearing or the bracket holder however he phrased that. It's thumping and vibrating - sometimes very badly and I won't go over 30 mph to keep it quiet. then sometimes it fades to really low noise / almost gone and I'll drive 50-60 mph ok.

POWER: Seems on the flats the car move OK - just ok. It doesn't have good acceleration at all, but it does accelerate. Like 70% power feeling.
Under load uphill exposes serious problems. Like 20% power feeling.