1998 V70 - Rough idle, hesitation, stalling

robisindy · Post by **robisindy** » 30 Mar 2016, 10:01

I recently purchased a 1998 V70 wagon, naturally aspirated. This is my first Volvo, so I am getting a crash course when reading these forums and trying to figure out my issue. I apologize if this post is too long, but I want to be as thorough as I can to try and answer some possible questions without them having to be asked.

The guy I bought the car from told me that the car had a driveability issue where it would occasionally stall when coming to a light and then take a few tries to get started again. He had just changed the MAF sensor and replaced the thermostat before putting the car up for sale. The check engine light was coming on, and he said it was throwing a code for the MAF.

I took it on a few short trips to try and see exactly what it was doing. It would start right up every time, even on cold days. But after it would warm up, it would be smooth going down the road but want to stall out when I'd come to a stop. Or it would run okay until I stopped somewhere, like to run into a store, but then when I'd come back to the car and try to start it up it would be hard to get it running. It would sputter and die, eventually starting up and idling okay, but if I goosed the gas pedal it would sputter and occasionally stall out. I found that if I held it around 2000 rpm for 1-2 minutes it would start running fine and keep running fine for the rest of the time I'd drive it.

After the first fill-up that I did, the car gradually ran better. For a whole week I did not have one issue with it - no rough idle, hard starts, nothing. It ran perfectly. This included one trip of about 50 miles round trip. Then this past weekend while on a longer drive it started to act up again. It ran perfectly on the 50 miles or so to my destination. But then after it warmed back up on the drive back I noticed as I was going down the road at around 50-55 mph it started to surge under light throttle. If I mashed the gas down it would respond as it should, but under light throttle just keeping it at speed it would be rough. As I came to a stop, the rpms dropped way down like it was about to stall but then bounced back up, then it was idling up and down while I was at a light. This continued on Monday on another trip of about 30 miles, once the car was warmed up (not right away, but eventually) it was surging under light throttle at 55-60 mph. Then it stalled as I was turning into the parking lot where I was headed.

During the time that I've driven the car, the ABS/Traction Control lights and the Check Engine and Service lights would intermittently be on and off. There was no rhyme or reason to when they'd come on or turn off.

Since I'd never tried the "re-learn" procedure, I gave that a shot before leaving my destination to return home. I unhooked the battery before going into my appointment, and when I came out about an hour later I hooked it back up. The car ran smoothly at first, but then eventually started surging again and stalled as I came to a stop at the bottom of an off ramp on my return home. It took 4-5 tries to get it to start back up. During this trip home, no lights came on on the dash.

Upon returning home, I disconnected the MAF sensor to see if that made a difference. It idled smoothly. When I took the car for a short drive yesterday it started acting up again. I immediately pulled over, with the car stalling out as I came to a stop. I got out and unhooked the MAF sensor again and started the car back up. I finished my short drive with the sensor unhooked and the car ran fine the whole time.

So, am I to assume that the MAF sensor that the guy installed is junk? Also, I am attaching a picture of the MAF sensor connector, because it looks to me like a plastic tab inside of it is missing. Does anyone think that this could be the issue? I don't want to buy a new MAF sensor if it isn't going to solve the problem, of course.

One other note: the ignition switch has been a little touchy, but not seeming to be as serious an issue as some of the things I've seen people say about these cars. A couple of times it hasn't seated all the way into the run position, and the shift interlock won't let me get it out of park. A little tap on the key is all it takes to get it corrected, and I've gotten into the habit of just making it sure that the key is in the proper position as I turn the car on. I don't think this would have anything to do with my other issues, but I figured I'd mention it just in case.

Post by **erikv11** » 30 Mar 2016, 12:33

Welcome to MVS, thanks for the detailed post.

If the MAF sensor is not Bosch that seals it, it is junk and must be replaced. If it is Bosch, then more troubleshooting may be in order. The connector looks OK to me but I may be missing something.

The ABS issues are a minor nuisance, rebuilding the module will fix that. The electrical portion of the ignition switch can be a safety hazard, e.g. if it fails at night on the highway all lights could go out.

Post by **misha** » 30 Mar 2016, 17:24

Disconnect the maf,start the car and if it runs better without it....that's it.
Also,like Erikv11 said...if the maf isn't Bosch....it MUST be Bosch 0 280 217 107.
Aftermarket maf will NOT work on these cars.

Post by **abscate** » 30 Mar 2016, 19:04

If that connector is bad you will waste money on a new MAF

Can someone with a 1998 snap a pic of your connector to compare please?

Your ignition switch could be the source of the intermittent lights and warnings

Don't let peopl read code son your car without telling you the actual code,format P1234. Most people who say there is a " MAF code" get it wrong

Post by **chrafael** » 31 Mar 2016, 18:05

Mine is a 98 v70 glt. Looks like it needs cleaning but otherwise the same.

Post by **abscate** » 31 Mar 2016, 20:53

Is that green gunk corrosion? If so, you have to get that off those connections

robisindy · Post by **robisindy** » 01 Apr 2016, 07:31

So, an update on the car...

Yesterday I started it up with the MAF sensor still unplugged. It started fine, but as I backed out of my driveway it sputtered and died. It started back up but if I gave it gas it was not very responsive and would run rough. I shut the car back off and plugged the MAF back in, and it started and ran okay to my destination, which was my barber (just 2 minutes from my house, so not necessarily far enough for the previous problem I've been having to definitely manifest itself). I will be taking it on another longer drive this morning. I'll report back on how it does. But the fact that now it ran rough with the MAF unhooked has me scratching my head.

Post by **abscate** » 01 Apr 2016, 08:14

Time to get into diagnostic mode. You need to evaluate fuel spark timing systems and figure out where the fault(s) is (are)

These cars are too complex to troubleshoot by symptom (i.e. stalls at stop light, must be MAF)

Skip the MAF
Fuel pump relay, wiring, fuel pump?

For a new to You car, I would check compression before putting any money into it to know where my engine is.

Post by **erikv11** » 01 Apr 2016, 11:11

Stalling at idle is most commonly associated with vacuum leaks. Check all of the vacuum hoses for condition (20 year old rubber is often crumbly and leaky) and proper connections.

Fuel pump relay is a good idea too, I would check that.

Actually I would not skip the MAF at all, this basic question is still a key one: what brand is the MAF?

Post by **misha** » 01 Apr 2016, 13:28

While vacuum leak can cause stalling at idle....rich condition can cause that too.

Is there a black smoke from the exhaust while engine is idling?
Do you smell unburnt fuel from exhaust?
Read the codes and post them here.

Again...what brand is the Maf?
Also,it could be iac valve that needs cleaning since all of the problems happenes at idle.

Cap,rotor and spark plugs....what is their condition?

Ect sensor.
Could be anything!Read the codes.