Alright, so I did some searches on this forum, but didn't find exactly what I was looking for.

My girlfriend drives a 1998 V70 (non-turbo) with 120,000 miles on the engine.
A few months ago, it started to hesitate under acceleration, and stall occasionally at idle. Over a couple weeks, it got worse, and stalled a couple times while driving. The check engine light came on, so I took it to get the codes scanned, and it came up with "System Lean". Then a couple days later it came up with the MAP/MAF code. The really annoying part about it is that it is so irregular. It will be hesitating and stalling, then running perfectly fine a couple hours later. We had taken it to the shop right after it was acting up one day, but they said that when they test drove it, it ran fine. It doesn't seem to be dependent on the outside temperature, but does seem to happen when the engine is warmed up.

I had thought it might be the MAF, so I got a remanufactured Bosch MAF through VASCO. When I installed the new MAF, the car wouldn't even start. It was like it wasn't getting any gas to the engine, so I took it out and put the original back in, and the car started. I made sure that the part numbers were the same, which they were, so I figured that it might just be defective. I returned it and got one through NAPA, same part number. After I installed this one, the car started fine, but there was a lot of smoke coming from the exhaust. I let it idle for about a minute to see if it would stop, but it didn't. I put the original MAF back in, and it started up fine. So we dropped it off at the local shop tonight, but I'm afraid that it won't give them a problem if they just drive it around the block. She can't go too long without a car to get to work, and can't afford to be spending a ton of money replacing everything, trying to find out what is wrong with it.

I don't understand why it would work with the original MAF, but not the new ones.

What are your thoughts on what this could be? Throttle body? Main computer?

Thanks in advance,
John

 

I guess I should have said that when it is acting up, before it stalls at idle, the RPM will drop to 2-300, then jump back up to 900-1000, and then drop again, and so on.

 

Hmm. I've had this issue a bit but it hasn't stalled. I had the ETS software upgraded and that solved my cruise issue and stopped the light from coming on, but it still has that issue when I slow down. It goes down to about 200-300, then back up to normal.

 

I'm not a mechanic but this is acting the same as my 2000 V70 crosscountry was before I had the software update for the ETS. I have not had a problem with the car since this update in this manner. I did have the intake for the turbo hose clamp break and the car would not run, just enough to get it off the street. It was emitting black smoke out the exhaust when this occured. You say your car is not a turbo. I was told by the used car sales man that my car was not a turbo also when infact it was. One thing you should check is that all your air intake hoses are secure because this could effect the MAF which was the code that was coming up on my car when the turbo hose clamp broke.

 

Well, the mechanic (used to work at Volvo dealership) said that it was just the connection to the MAF, and he cleaned and regreased it. It worked perfectly until yesterday, when it stalled again. So it is definitely something with the MAF or the MAF wiring.

Should I just clean and regrease that connection every couple weeks when it starts acting up again? Or will the repeated stalling every couple weeks damage the engine or something else?

Thanks again,
John