Hi, I am new to this forum and just purchased a 1999 V70 XC with 130k on the clock in "running condition" for $400. Haha. I just want to list out my first observations and give some info on the car so that I can get some recommendations on where to start. This is my first turbo car and my first "modern" Volvo. I do have some mechanical experience and have done troubleshooting on mostly 1st gen. gasser VW's and older 240's.

Ok, so..

-The car sat for about 18 months- 2 years and had very little fuel in it. When I got to the car, it had already been jumped and started by the owner, so who knows if there is any damage to rings, etc.

-The car has plugs, coilpacks and coilpack wiring repaired by the only Volvo shop in the county about 4k miles ago.

-There are mechanic's notes noting that an inspection was done for excessive oil consumption and found that there was "excessive oil in the intake manifold, suspect turbo is defective". This assessment was done by a a local shop that deals mostly with Mercedes.

-I have not performed a vacuum gauge test yet, but noted that with the "glove test" at the filler lid that there seemed to be no vacuum and no pressure either; kind of neutral.

-The ETS light is of course on and I did manage to pull a PO121 Throttle Position Sensor/ Switch Range/ Performance problem. I take that to mean the potentiometer in the ETS is broked. That code since went away, though the ETS is still on.

-Mechanic note that fuel pump is going out?; I will test pressure in the next day or so. I am not getting ANY rest pressure, but the car does fire up and run. Is the check valve for these on the pump? can I change out *just* the pump?

-The car variously runs between 700-1000rpm at idle, with smooth- ish periods at around 900-ish rpm. It doesn't really lope or hunt, just kind of goes from one range to another. It also sometimes falls to 550rpm or so, no real pattern.

-At steady throttle in Park, it feels/ sounds almost like a backfire/ miss from about 2500rpm on up. Kind of a chuffing.

-It is on old, bad gas. I did add a gallon of fresh when I drove it home. It is just to the reserve level now. Garage was stinky and kind of hazy after I ran it for 10 mins or so; but can't determine if it's the fuel or oil or whatever.

-Did not notice any smoke trailing while driving home; only about a mile.

I do plan on cleaning the existing or replacing the ETC with a used one if I can find one. The plan is to absolutely not get upside down on the car, so I will not xmodex/ buy new turbo etc, until I am confident in the long term viability; happily, though, I do have spare time and enjoy my garage time.

I'd be grateful to hear any thought or ideas that you might have on how to proceed. Thanks

 

The ETM is shot... your best option is probably Xemodex. The issue with replacing it with a used one is that it has to be coded to your VIN or it will not work. Unfortunately you can't just swap these back and forth. I would attribute the idle surging and the miss to that for now.
The fact that there is no pressure or vacuum leads me to believe the PCV is in okay condition, but not great. It'll need it done soon, but it's likely not severely clogged if there isn't any significant positive pressure.
The oil consumption could possibly be attributed to a clogged PCV. Remove the intake elbow (just past the MAF sensor/air box) and see if there is oil in the bottom and in the turbo inlet. You may notice a spray around the PTC, meaning it's time to replace the PCV. Also go ahead and check for shaft play on the turbo CHRA, which would indicate a bad turbo, especially since you have oil consumption. Just reach into the turbo and try to move the wheel back and forth on the shaft.
Put some fresh 93 octane in there... the old gas probably has a bit to do with it running badly. A bottle of Lucas or Techron couldn't hurt either.
The fuel pump itself can be replaced. Just order the OEM Bosch insert (JUST the pump) and replace it, no sense in replacing the whole assembly. They usually go out around 170k-180k, but it couldn't hurt to go ahead and replace it now anyway, especially considering how long the car was sitting.
Also go ahead and replace the fuel filter.

 

I did replace the ETM in this car after utilizing the diagnostic PDF's on XEMODEX site; which were very helpful. If I end up keeping the car to drive and not selling I plan to buy the XEMODEX unit.

I got an ETM at a junkyard; it is from a 1999 V70 XC, so the same car, basically and it works excellent. I have about five hours running time on it in my garage and driving around my property, I haven't tried to register it yet due to more work that needs to be done. Anyway, the car does have an open recall for the software at the dealer, so I may get that done although, like the junkyard, it's a good distance from me.

I don't know, but suspect from my research online that the '99's have less discrete match programming and maybe the 2000's have more variants? But the one I got seems to work flawless.

I did replace the PCV system except for the plastic box and the "expensive" line, which I reamed out with some cable and it seemed fine anyway. The car does now have vacuum and I did replace a few vacuum lines as well, so I can't say as the PCV was the culprit, but it is now done.

I just received new fuel o-rings and got a set of injectors from the JY car which seemed to be in great shape except for the head gasket, so I will try those to see if the rail will hold pressure.

Good times!

 

Glad to hear the ETM is working now. I might have misread this in the past, and it has to be the same model and year, like the one you got (LPT, 1999).
As for the PCV, the oil trap is one of the more important things to replace in that job, but being you have lower mileage, you may be good. The "expensive" line, being that your car is a '99, is not as important to replace. On -1998 cars, it's made of plastic and cracks from engine heat. Volvo corrected this for the 1999 MY, and it's not as much of a problem.
Make sure the vacuum lines on the sides of the intake manifold are connected. Also check the TCV hoses and the purge valve/evap vacuum hoses. Most likely, that's where your leak is coming from.