MIL light again and again...

850Cal · Post by **850Cal** » 12 Aug 2006, 23:10

My 97 850 wagon has been plagued with not starting or hard starting for over a year now. Even after a major service (including a timing belt) it would sputter before coming to life. The Indy and the Dealer both claim they are getting "Miss-Fire" codes, but my Innova scan tool has consistently given back "Rich Mix" code every time. The Indy did a major service, but didn't replace plugs, cap, rotor and wires. I did this myself after the car left my kids stranded AGAIN, but problems still remain.

I went back to the Dealer and had the codes read. They replaced the MAF sensor but the CEL returned within 50 miles. I checked and the code was "Rich Mix". The Dealer took the car back and reported "Misfire" codes as the problem. They suggested replacing all the wires, plugs, cap and rotor, to the tune of another $400 beyond the $600 I had already spent! I replaced the cap and rotor, but after another hundred miles, the CEL has returned.

The car has 200k and I'm finding baked components everywhere. I replaced the Flame Restrictor and found some hoses that were badly deteriorated behind it. I replaced them, but don't know what else may be suffering in out of the way places. Maybe there are grounding problems in the wiring I need to investigate, too?

Any help would be greatly appreciated!
Thanks, Cal

stoutlogic · Post by **stoutlogic** » 13 Aug 2006, 09:23

I'm a alittle confused. When you say "major service" since when does that not include, plugs, cap, wires, rotor, air and oil filters plus oil change?

Anyway I would at least call FCP Groton and get yourself new plugs, and stock
wire set, do not get the Bosch wires. Cost may be $75 and 1 hour of your time.

Start there and post back.

Post by **MadeInJapan** » 13 Aug 2006, 09:38

Which plugs did you replace with? Also, were they at the right gap? Should be non-Bosch Platinums (everyone has trouble with those it seems) gapped at .028inches. I also agree with NOT using the Bosch plug wires (everyone has trouble with these too). If you by chance used them, switch over to OEM wires....Bougicord makes them (fcpgroton is your source). Other than that, seems you probably did okay on other parts replaced.

White850Turbo · Post by **White850Turbo** » 13 Aug 2006, 16:35

What's the specific alphanumeric code the scanner is giving you?

850Cal · Post by **850Cal** » 13 Aug 2006, 17:42

Thanks for the responses so far. It turns out I am using Bosch plugs and wires. (And I found it incredible that I could spend $1100 on a service that didn't include plugs, wires, cap and rotor! Needless to say, I haven't returned to that shop.) But since I replaced those and repaired the hoses by the flame trap and replaced it (what the **** is a flame trap???) the car has run OK, just hesitates a bit when it starts. The recurring CEL is the real issue now.

The code I keep getting is "P0172" from an Innova 3100. The book says "System too Rich (Bank 1"). I have no idea what that really means. I did find a hose that runs from the intake manifold to something mounted on the fan shroud that was so baked it fell apart when I touched it. If it was leaking, it would be sucking air into the manifold after the MAF sensor and Throttle Body. I'm in there now because of Starter Motor problems, but that's the subject of another thread. Thanks again for the help.

-Cal

Post by **MadeInJapan** » 13 Aug 2006, 20:02

The "bank 1" issue is usually a front 02 sensor going bad, or gone bad, but with vacuum leaks, they can cause it too. Check your other hoses and "elbows," which are the more robust 90degree rubber joiners at the intake manifold. See if they are cracked as well. Once you fix all of your vacuum leaks, reset the service light and see if you still get the code. If you do, then I would suspect the 02 sensor. How is your gas mileage? A sudden turn for the worst is usually indication of that sensor gone bad.

850Cal · Post by **850Cal** » 13 Aug 2006, 22:22

Thanks for your help. I found the PO172 section here and am working my way through it. So many hoses, so little time! I'm sure I'll have more Q's after reading through this. This car has been so good until the last 20k miles from 180. Is there a site with a diagram for the hoses on a n/a 850 as there is for a Turbo?

Thanks, -Cal

l33tDad · Post by **l33tDad** » 14 Aug 2006, 07:25

Try Bay 13

Post by **MadeInJapan** » 14 Aug 2006, 08:25

850Cal wrote:Thanks for your help. I found the PO172 section here and am working my way through it. So many hoses, so little time! I'm sure I'll have more Q's after reading through this. This car has been so good until the last 20k miles from 180. Is there a site with a diagram for the hoses on a n/a 850 as there is for a Turbo?

Thanks, -Cal

The one posted here from an S70 (mine) was found under the hood (on the hood itself), near the passenger side. I suspect your Volvo has the hose diagram for your car too...it's on a white sticker. It's so small that it's hard to read. Take a digital picture of it and blow it up on your computer screen, then print it out if you need it at the car. Good luck!

Post by **pfeener** » 14 Aug 2006, 08:48

To be fair to your car; I'll bet most of the service you've had performed on your car had nothing to do with, and no effect on, the CEL you were/are getting. I'd love to know what was done for the "major service" on your car for $1100. I'll bet most of it is "fou fou dust" repairs.

MIJ is right on; your problem has a high probability of being caused by a vacuum leak. The O2 sensors are usually good for around 100K miles, so if yours is older than that it's a good bet to replace it anyway. I would stick with a genuine Volvo sensor. You can get them for a little bit of a discount from myswedishparts.com.

Changing out the Borsch wires and plugs for OEM parts is a good idea as well. Lots of issues with the Borsch wires and plugs. FCP has the genuine Volvo plugs and the Bougicord are the OEM wires. There are exactly (right down to the stenciling on the wires) what you get from the Volvo dealership.