Oh boy. I screwed up today, a full tank of 87 regular into my 98 V70R. It ran OK most of the way home (40 miles). I had to stop at the end of an exit ramp and when I pulled away the car bucked and snorted, no power, a FLASHING check engine light (which I'm pretty sure means a nasty skip) thought it would stop dead. Flashing stopped but the light remains on. At one point during the remainder of the drive home I gave it about half throttle and it started the bucking and flashing again. Maybe a bad tank of gas, but I doubt it as I get gas there regularly. Could regular grade make this happen?? I'll have to pull the plugs and have a look-see but this was a pretty drastic effect for just a lousy tank of regular gas. Car is definitly not running very well even at idle. I had a OBD2 scanner on it today to clear my P0410 code. While I was doing that I was watching the engine timing at idle. It was fluctuating between 4.5 and 6 degrees at idle. Could any of this be telling me the timing belt is getting ready to give up the ghost?
Advice greatly appreciated.

 

Sounds like you might have water in the gas. No way would just a tank of regular cause that much of a problem. I use regular all the time in both of my Volvo's. I don't see the need to spend the money on higher octance when mine run fine on 87.

 

I just went outside and started it. It really is skipping pretty bad. The motor sort of shakes and feels like it wants to stall out. I'm going to throw in some dri-gas, but I'm not sure about the water in the gas since they have ethanol in it now anyway. That should have mixed any water in pretty well. The gas staion is a high volume Mobil too. Damn!

 

Did you ever get the tune up done on it yet?
Flashing Check engine light means Missfiring.

 

Just ordered a set of plugs, a cap, a rotor and new OE wires. Do I have to take the turbo tube that runs over the motor off to get at the plugs? I do know to remove the cover. The job looks easy and hopefully I'll be pulling out some well worn plugs. I'm also going to clean the MAS and TB. CRC makes something for the MAS and I'll try that. I'll pull the codes again tomorrow which may lead me where I need to go. Tune-up regardless since it probably needs it. Yeah, it'd be nice if the car was a "turn-the-key-and-go" model, but at least I'm getting baptised in fire and should be well versed in Volvoese by the time this thing is running right. Glad it's not winter :-)

 

You can sneak it out without removing the tube.
I never remove the tube to get it out.
Alot of people do but I never do.

I will bet it is missfiring due to needing the tune up.

 

You don't have to take the tube off as tech says. I like to take the 10mm nut off the bracket of the pipe and that will give you a little more working room. When removing the plastic spark plug cover, go easy on the torx bolts as they are known to strip if you don't get a good grip on them. When I put them back in, I use a little anti-sieze on the bolts and don't torque them too tight.

 

I pulled a P0301 - cyl 1 misfire code. That was the only code stored. Is cylinder one on this engine like cyl 1 on some engines where a lot of calculations originate like for firing the other plugs, timing, engine load etc? I ran the engine for a bit with tool attached. I was monitoring the two O2 sensors. The one closet to the engine showed a regular ticktock type fluctuation in voltage output. Number two though showed very little fluctuation and held pretty much at .495 to .525 volts. # 2 is after the converter I think. Is it's only reason to live to see if the converter is working properly? The car wasn't being driven, just idling in the driveway with me revving it up and down. I guess what I'm asking is if cyl 1 is having problems could it make things seem a lot worse than a simple misfire. I'll change plugs as soon as it stops raining.

 

#2 sensor is there to make sure #1 is doing its job.
No every cylinder has its own info.
You just have a problem with #1 cylinder.

 

I'm pretty sure it was the plugs. I changed them this afternoon (finally an easy job on a Volvo!) and the car seems to run much better. The plugs I pulled out maybe weren't the originals but I sure it wasn't any more then the second set. 1/4 inch gaps, center burnt almost to the porcelain. I put DENSO's in it beacuse I had ordered a set a while back. I have wires, a cap, a rotor and Bosch Platinums coming and I'll probably swap these in for the Densos. Running fine on 87 octane now. Timing belt and water pump next!

 

Cool glad it was simple for you to figure out.