2004 XC90 Help. Possibly Electrical?

blackmonk2 · Post by **blackmonk2** » 25 Aug 2016, 11:02

I recently purchased a 2004 XC 90 with 154,000 miles on it. Car ran great for three months. Then about two months ago, the car started jumping/skipping/jerking around 50-70 mph when giving it gas. It slowly worsened. Then it began to randomly cut off.

It would cut off when I gave it gas after stopping at a stop light. It would cut off driving down the road. But it would always crank right back up and be fine. Until it didn't.

One day it just wouldn't crank back up. It would turn over but not fire. I took it to a local shop, who has great reviews, and a Volvo specialist on site, and they replaced the Crankshaft Positioning Sensor.

The car ran great for about a month. Then it started acting up again. Same problems. I took it back to the same shop and he says he cannot get it to act up again. And cannot pinpoint the problem if it doesn't. Say's he test drove it three times but it was fine.
I gave him this write up of when and how exactly it acts up when it does. I’ll include it below:

8/16 -7pm-
filled up gas tank. Went to Walmart. Leaving Walmart I was stopped at a stop sign. Light turned green, gas it gas and went about ten feet into the intersection and the entire gas cut off. Pulled over to the side of the road and it started right back up.
But when it did it felt like the rpm couldn’t get past 2 or 3. It felt like it was struggling to go. I stopped a gas station 200 yards past that and cut the car completely off. Went inside for maybe 3 minutes, came back out and started the car and it was fine. Everything normal.
On the ride home on the interstate accelerated to around 50mph and the car shuddered again. But stayed on.
8/17 -7:30pm-
Made it all the way home and as I was pulling into the driveway I brake into the spot to park and before I can even put it into Park, the car cuts off. It starts right back up and I drive it around the block with no problems.

8/18 11:00am
Getting onto Interstate 77, I accelerate to around 50 mph and the car gives a shudder but stays on.
7:00pm
I was on the way home and there was a traffic delay. I sat in very slow traffic for about 20 minutes. Then finally got through the delay, and was going only about 30 mph, and the car just cut off. No extra gas given or any turning or anything. (Just out of nowhere. Didn’t seem to be a reason, unlike the other times where I had given it extra gas to either accelerate after a red light or just to go faster.) Pulled over to the side, crank right back up, and drove it 2 miles to home.
8/19 11:00am
No problems this morning. Made sure not to really gas it however.

So now he's saying to keep driving it and when it starts to have problems more frequently, come back and he'll take another look at it. I just don't feel safe driving the car when it randomly cuts off driving down the road. And when it jerks going 60mph down the interstate.

Any help or ideas would be greatly appreciated. I know this is a long post, but I'm trying to give all the information I have to better help understand the problem. Don't really have the funds for a huge problem so hoping its just another sensor or something.

Thanks for the help!

finding41 · Post by **finding41** » 25 Aug 2016, 20:02

Get yourself a code reader. If you spend about $100 you will get one that is good enough to accurately point out the problems. Spend less and you will have an idea of what is wrong but not the whole picture.
You can Google the codes to find out what they are exactly. Then you can diagnose most problems yourself.
What you describe sounds just like the CPS. But the CPS is new... Right?
The problem could be a bunch of other things. MAF, O2 or a bad coil....? Reading the codes will let you know.
Good luck.
Marty

blackmonk2 · Post by **blackmonk2** » 26 Aug 2016, 13:17

The problem is it's not throwing any codes right now. Do you think it could possibly be the fuel pressure sensor?

FREE-PPV · Post by **FREE-PPV** » 11 Sep 2016, 18:16

Going through the same exact issues, very frustrating as I can usually can use diagnostics and fix anything, but this one has me stumped. It is definitely fuel pressure issue, but it only happens after car fully warms up in about ten minutes of driving and this is consistent. Replaced everything from filter, fuel pressure sensor, PEM and fuel pump, same issues, it drops from normal 44 PSI range to below 10 PSI when accelerating. Won't die completely yet, but sure is frustrating. I also pulled CEM and it did have water corrosion from plugged sun roof tube drains, so fixed that, cleaned up CEM board with electronics cleaner, still same issue. Pulled codes, p0087-89 and given I have ability to watch fuel pressure drop with my smart phone, it is obvious what is happening, but why is question and having gone through dozens of forums, no help to date. If it didn't act up only when warmed up, it would make more sense, but what changes in fuel system related to heat?

finding41 · Post by **finding41** » 20 Sep 2016, 20:31

I would suspect the CPS as well. Check that it is installed into the block properly. Also Check the confection at the plug for corrosion and connection. Look for worn wires while you are at it.

Post by **Roger_850T** » 23 Sep 2016, 21:37

Some vehicles have electronic fuel pressure regulation - it reads the pressure, and changes the voltage to the pump to speed up or slow down the pump accordingly.

If you have VIDA, perhaps it would help to watch these signals. Maybe have someone else drive while you watch them with fuel pressure and fuel pump signal in the watch window, and see if you can see what is happening. It may be the fuel pressure sensor with a bad reading, or the pump may not be responding to the signal to speed up or slow down.

When was the fuel filter last changed? It's probably not the issue, but wouldn't hurt to rule it out.

Roger