96 850turbo, 88K mi, very well maintained. It's had a clean history w.no issues to speak of, nothing major or minor replaced, etc. Ran fine this morning. Went to start it now and CE light is on but idles ok till I put in reverse, gets a little rough. Shut it off. Started twice more, ea time much worse. She'd start ok but immediately run very rough, cough, the overdrive off light flickers and she dies.

Any idea what could be going on? Anything I can check before calling a tow?[&o]
Thanks for your help!

 

The codes out of the computer would be a big help.
Maybe a mass flow sensor. But the codes might lead right to it.

 

I did some browsing here and have seen a lot of talk about codes, but how do I access them? Sorry, never done it before. Do I need anything special? I'm a handy wrench but haven't dealt w.these type electronics.

thanks!

 

You would need an OBDII scanner.
I believe you can rent them from some autoparts stores but not 100% sure.

 

I'll check into renting one, thanks. Mean time I'll try to find a used sensor locally and have it to try now. Worst case I have a spare which woulnd't be bad. The sensor on my 740 turbo went at around 180K mi. so I know it can happen w.out warning.

 

OBD-II: On-Board Diagnostic 2nd Generation;a method to access fault codes stored in the car's computer.

'93-'95 850s have OBD-I, which is in the engine compartment and you can access the computer;ECU (on-board Electronic Control Unit) without any special tools/testers. Unfortunately, your 850 is a '96 so it does not have an OBD-I.

I would locate the nearest AutoZone, as they offer free OBD-II diagnostic services. They'll hook up a scanner/tester into the car's OBD-II port, turn the ignition switch to the 2nd position and then the scanner/tester reports if there are trouble codes in the ECU. If there is no AutoZone near you, other auto parts shops may provide the same services. The dealer usually charges approx $100+ for this. And as a courtesy, I usually buy some consumables after an AutoZone does this service (oil, fluids, light bulbs, shop towels, etc...)

http://www.autozone.com/store_locator/home.htm

General maintenance tips:
https://volvoforums.com/m_48928/tm.htm

Best of luck to you,


JPN

[IMG]local://upfiles/6892/9C11C60D02C64BF6B3A0E0C88ACC7019.jpg[/IMG]

 

JPN, thanks for that - very helpful! There's no AZ nearby but I'll figure it out...

 

Knowing what you do about my problem, do you think it's a bad idea to limp the car 10mi to autozone for error code check? I dont know if it'll get out of my neighborhood really but if it seems ok I'll go for it. Just thinking it may work out since when the sensor went on my 740 I was able to drive it 50mi to my shop.

 

If the Mass Flow is bad and you unplug it the car should idle almost perfect.

 

I unplugged the 4-spade connector to the unit and while it improved the idle a bit it still stalled as soon as I put it in gear. If I removed the unit altogether would the car run ok? Not suggesting I would do this, just curious from a dx standpoint.

I had it towed and guess what - it was the mass flow. I'm planning on replacing it w.a used unit for $60 (vs $170 new sourcing from ebay). The shop, which I believe charges $90/hr, quoted me $370 all in. I think either way I'll bring them the part and let them install.

Is this something I could install w.out special tools (electronics I mean)? I know I can put a new unit in- that should be easy - but not sure if there's anything else I need to do from an electronic standpoint.

 

I wouldn't buy a used electronic device. MAF sensor fails due to age & use, and if you buy a used unit it may fail again soon. I know new sensors are not cheap, but a used unit may make you buy another one soon, which would become about the same price (or more?).

I have not replaced a MAF myself yet, but I believe it is an easy job; remove the old unit & install the new one in. Other members who have done this could give you better directions, but in general when you replace an electronic device, make sure that the ignition switch is off and do not touch metal pins in the sensor connectors with bare hands, because some electronic devices are electro-static sensitive and would be damaged from your static discharge.

2 parts vendors some of us have been using:
http://www.fcpgroton.com/volvo850fuelsystem.htm
http://www.eeuroparts.com/searchresu...7&cat=1010

They both are priced at $168, FCP Groton seems to have Genuine Volvo or Bosch. Again, it is expensive but if you plan to keep your 850 for more than another year, two or longer, I would definitely get a new one rather than gamble with a used one.

Also refer to this FYI:
http://volvospeed.com/Repair/maf_secure.php

I would also buy a Haynes repair manual; only $14~$17. It may have instructions for MAF removal & installation and will save you some $ in the future.

Let us know your findings if you would.


JPN

 

After installing a new Mass Flow all that would have to be done is the codes cleared.

 

Point well taken JPN. I'm just going from my past (single) experience w.the 740's (car-god rest her soul) MAF - replaced used and it went at least another 2yrs before the car died.

Any way, I think I'll throw the shop guys a bone and just let them supply the part. Wouldn't want to sour the relationship right off the bat I guess. Ah hell I dunno...could save some decent money!

 

I've found that about half the timethe MAF (AMM) can be cleaned and it will work OK. I would risk $3.00 or $4.00 on a can of MAF cleaner or electrical contact cleaner (both are CRC products and they are available at any chain auto parts store) and give it a try.

The important thing is to just spray it and let it dry.Don'tscrubit, don't dry it, don't even touch it. You may not even want to look at it, they are about that sensitive.


...Lee

 

About three months ago our 95 850 turbo had a similar issue....rough idle, die when you put it in gear, barely start...... I pulled the codes and had a 123 code saying it was a bad coolant temperature sensor. I replaced the sensor, and the car is fine. SOunds like that may be your issue, but as others have said, you really need to find the code(s) setting the check engine light.

Good luck

 

***** FOLLOWUP & RESOLUTION: ******

It was the MAF gone bad. Got a local autoparts store to order (had it in 4 hours!) a new MAF for me this morning. With the returned core ($30) it cost me $125, + $90 labor to install and reset the codes (which can't be THAT time consuming can it?!). Not bad for $215, considering if I had the shop do it all it'd have been $370 + tax. Shop guy was really cool about it and didn't resist installing customer-supplied part.

Thanks again for your help.

 

And the problem solved, right?


JPN

 

Err, yeah, solved. It was in fact the MAF. (sorry, thought I mentioned in a previous post they positively MAF coded it).

 

Well done!!!


JPN