Re: 1999 S70 runs then dies (1Wagon post)

[abscate]

Okay,we are getting somewhere. no idle. Unlike the earlier cars, you don't have an Idle Air Control valve on your 99.

Experts, I'm thinking a Mass AIr flow sensor (MAF) replacement might be indicated- what do you think?

Amy - a MAF from IPD runs about 150 USD for your car. I dont want to dive in and replace it quite yet so I will try to find the diagnostic procedure to see if we can test this before jumping. You can disconnect the MAF and see if the engine will then idle - but the car can take 10 minutes or so to relearn the MAF/ECU combination so don't do it with your patient in cardiac arrest in the front seat.

To disconnect MAF - see link here...

https://www.matthewsvolvosite.com/forums ... hp?t=11193


.... on locating it and the connector (just remove connector from MAF body, leave MAF in place).



I have these test specs from AllData but unless you have a air flow sensor these arent too useful. Someone recently posted the pinouts and resistance readings so I will try to find these.

Test specs

Mass air flow (MAF) sensor resistive film.
Measurement range 12-640 kg/h.
Q (kg/h) 12.0 15.0 30.0 60.0
V (volt) 1.31 1.39 1.69 2.11

technical info on MAF here

https://www.matthewsvolvosite.com/downlo ... irmass.pdf

[1Wagon]

I did replace the MAF myself about three years ago. Not to say that it doesn't need to be replaced, but how long do they normally last? Before I replaced it, my wagon's "symptoms" were different than they are now. Back in 2010, it was more of a bucking of the car than stalling out dead when no idle pressure.
Could it possibly be the battery? The gas pedal sensor? When I do drive around town, it will intermittently operate like it's going against a good headwind but will die when taking corners or at stops. It became a little on the dangerous side for me yesterday in an intersection.
As I mentioned before, if I am at a stop light, etc. I have to really rev the engine to at least 1500 rpms (and yes, I get looks like "What is that idiot doing? Does she want to race??" ).

Wow, we are already 6 pages into this topic. We shall find a remedy soon! Even my 5 year old son asked if my "junkie car" was sick or had hiccups. I said, "No, she's just a little down and out lately."

Please keep me posted on what I shall do next.

PS It couldn't be anything very simple like fluids, filters, etc.?

Thanks,
Amy

[abscate]

Its something simple like a broken hose or a bad component, but not a filter/fluid IMHO.

Ive replaced my MAF 2x on the way to 150k miles, so 3 years/50k (?) isn't outrageous to consider.

Let's try unplugging it and running the car in safe driving place. If the MAF is unplugged, the car defaults to a set of parameters that will make it anemic but run ok. If the bucking/stalling stops, we are onto something. See the link above on how to unplug but it is simple - just squeeze wire bail and pull plug on MAF, once you have located it.

6 pages ?? We are just getting warmed up...

For Junior - "She' sick, but remember she is paying for your college in non-new car payments..."

[1Wagon]

I disconnected the sensor, ran okay. At stop lights I just kept it in park and didn't rev, thought I would just let we do her thing. She shuddered on two different stop lights only when it got below 1000 rpm, but did NOT die/stall.
I never revved as I wanted to determine if the unplugged MAF sensor was leading us somewhere.
I have a few more errands to run so I al going to leave it unplugged and see if anything changes.

To be continued...
Amy

PS I will add that the only light (in addition to the check engine light) that came on since I unplugged the sensor was the TRAC light/icy road.

[1Wagon]

Sorry for the typos, iPhone didn't pick those up....so goes the "smart phone".

[abscate]

Okay, drive it for a few days and see how it does. Sounds like we are making progress!

My teens are so great I added another one the easy way- exchange student from Europe with us for a year.

[1Wagon]

I drove around yesterday and it never stalled/died, even when doing the lazy Ametican coffee run through Starbucks drive thru.
Since disconnecting the MAF the car somewhat resembles the sound of a 71 CUDA idling.

Major problem this am when trying to leave for work:

Car won't start! Lights on dash on, headlights are on yet dim, and when I try to crank the engine over, it sounds identical to a 1940's gangster movie shoot out.

Is this te battery? Starter? Should I get the at towed to my mechanic at this point?
Help!!
Amy

[abscate]

Chatter chatter chatter chatter - the musical sound of a battery too weak to engage the starter and the solenoid going in/out.

The solenoid does two things - its a 'relay' that handles the big current (100 Amps+) that runs the starter motor. It also pushes the starter motor gear into the right place onto the engine to turn it over, then removes it after the engine starts, so that the engine doesn't spin the starter motor into little pieces.

First stop is battery - how old is it? I would buy a 12VDC charger at Sears/Autozone/whatev for under 50 USD and charge the battery overnight and see if that fixes it temporarily

Starting issue is unrelated to your idle issue, by the way, but I like that the MAF disconnect is helping diagnose that problem.

[1Wagon]

This battery is about 3 years old and it has caused me problems in the past year. I have been towed to my mechanic a bout 2-3 times when it doesn't start only to find out but he time it arrives to the shop and he takes a look at it, it starts up fine (or tests fine: voltage, etc). AAA has told me that they can't tow me again if its related tot his particular battery in my car. I say just replace with a new battery and see what happens.
I don't have the time to buy the 12VDC charger and sit on this all night on;y to find it won't start up tomorrow.
(Too much detail but I am home solo with just this one car for the next 7 weeks and need to figure this car thing out pronto...).

[1Wagon]

I apologize again for the typos (hopefully Matthew doesn't see this!). I am very meticulous with spelling and grammar (spelling bee winner extraordinaire) but seem to type so fast on here with my iPhone and not all the errors are caught. Sorry guys.