2001 XC70 won't stay running

[kain]

Car was driving fine today, no issues. On the way home it was raining a good amount and the lane I was in on the highway had a good 2-3 inches of water covering at least 1/3 of the lane. Traveling 20 mph or so for a few min I had a good wall of water coming off my front tire the whole time. Not more than a minute later and I noticed my RPMs a little lower than normal at idle (approx 500) and was starting to feel a rough idle intermittently. I was worried I was gonna stall out on the highway in the middle of rush hour so I drove with two feet for a couple miles keeping the RPMs no lower than 1000 to keep it from stalling. I eventually made it to a gas station, put it in park, took my foot off the gas and the RPMs immediately shot down and the car stalled. I was able to start it just fine but it would not stay running. If I start it and give it a little throttle I can keep it running but as soon as I take my foot off the throttle it stalls.

Gas gauge was low and the DIM said 50 miles to empty. I bought a gas can and added a gallon so that I could rule out faulty gas gauge. Still same symptom.

Oil level was fine. Coolant level is fine. Didn't have any blown fuses. After the stall the CEL and oil pressure light were on the dash. CEL light was on prior to the stall though due to emission efficiency code so I am not sure if there is a new code that has popped up. May need to pick up a new OBD reader as I am not getting the thing towed to an AutoZone to have it done and my current reader does not have available drivers for OSX.

Is there an idle sensor that could be faulty? MAF bad? Not sure if the timing is just coincidence with me driving through water but I'm hoping it just a wet connector or something. Gonna give it a day or two to dry out and see if I still have the same symptoms.

[kain]

Quick update: I tried to start her this AM, fired right up and stayed running for approx. 10 seconds before she started to sputter and rumble and then eventually stall. Having her towed to the local indy that works on Volvos this afternoon to have them do a diagnosis.

[guyeye]

Vacuum leak? MAF?

[kain]

UPDATE: Cleaned MAF this weekend and changed out plugs just because I was due anyway then sent the car off to the shop. Just got a call from the mechanic and he said "ummm, I think it was just out of gas". [sly]

As of right now the mechanic said there are no codes in the system that would produce this issue. He also said after putting $20 worth of gas in it "could not be running better".

When this all happened the gauge read "50 miles to empty". I added a gallon (it was the biggest gas can they had) and still had the same problems. After changing plugs and cleaning the MAF sensor this weekend I tried starting it a couple of times and had the same problems; car would start right up and then would stall out after 10-15 seconds. Also, the engine would run as long as I kept my foot on the throttle but when I let the RPMs drop it would stall out.

Is there a possibility that this is evidence of fuel pump beginning to go south or a clogged fuel filter? In the past when my car has been out of fuel I could not even start the thing nevermind keep it running by giving it some throttle.

As always, thanks in advance.

[kain]

UPDATE to the UPDATE: New fuel filter will be here tomorrow from FCP, prob needs to be changed anyway. Also ordered a new MAF sensor just in case the problem rears it's head again I will be able to swap the new one in to cross that off the list of culprits.

[kain]

Not that there seems to be much interest in my thread but I will update to hopefully give someone something to go off of if they run into the same issue.

Replaced the fuel filter (5 min job TOPS) and MAF sensor. Have driven the car 400 miles since and the problem has not come back again, car is running great, fuel economy is even 2-3 mpg better. Not sure what played the biggest factor in that (plugs, MAF, fuel filter) but I am guessing it was prob the MAF.

Will update if anything out of the ordinary happens.

[guyeye]

Excellent!!!
And for the record, I was very interested.
Always learning...

[howardc64]

Chasing bad MAF problem is a pain. No codes, nothing. I only found it by swapping another car's MAF.

My failing MAF would just cut out engine power on me randomly and infrequently for few seconds and then all is running fine. Eventually, car would die coming to a stop. Again, randomly and infrequently.

Wish there was a good diagnostic for the MAF. Probably have to capture and record its output live to find it :(

MAF cleaner didn't help. Tried 2 non Bosch aftermarket MAFs, both were bad so stay with Bosch.

[marbs34]

Could carbon build up on the mad cause the element to retain heat forcing it to send a signal to the ecu indicating that a less than adequate amount of fuel was required hence causing the stalling issue?