1994 850 Turbo Running rough and threw a lot of codes

GDiode · Post by **GDiode** » 27 Jun 2015, 20:38

My daughters Volvo 850 started running really rough just when I got the new PCV kit to install. Here are the codes;
2-3-2 long term fuel trim, idling
1-4-3 front knock sensor signal
4-4-3 3-way cat. efficiency
3-1-5 EVAP system
4-3-3 rear knock sensor signal
5-4-3 misfire at least one cyl.
4-5-5 misfire cyl. 5
5-4-5 misfire at least one cyl, 3-way cat. damage
5-5-5 misfire cyl. 5, 3-way cat. damage
4-5-3 misfire cyl. 3, 3-way cat. damage
5-5-3 misfire cyl. 3, 3-way cat. damage
5-4-4 misfire more than one cyl, 3-way cat. damage
5-4-2 misfire more than one cyl.

We bought the car about 3 months ago and I don't know when the plugs were changed last. So I was going to start there. Any other suggestions on how to proceed from there. I do have a parts car a year newer with the same engine.

Thanks,
Shannon

Post by **Ozark Lee** » 28 Jun 2015, 11:35

When I have a gob of codes like that I usually clear them and see what comes back. It sounds a lot like a problem in the ignition system.

Spark plugs would be a good first step and while you are changing the plugs check the distributor cap and rotor. We have had several posters with similar problems report that the coil wire socket on the distributor cap had burned up. Another common problem with those symptoms is a camshaft seal leak behind the distributor that fouls it with oil.

Don't get real fancy with the spark plugs and stick with a single electrode type. The gap is critical and it should be 0.028 and error on the small gap side. The multi electrode types like the Bosch +2 and Bosch +4 don't have an adjustable gap and it is way too big.

If you need a new distributor cap and rotor make sure they are Bosch and if the ignition wires are bad replace them only with Bougicord wires. The latter are tough to find at the usual auto parts stores.

...Lee

Post by **abscate** » 28 Jun 2015, 12:02

Ditto that. Once they start running crappy, you get lots of codes.

All new ignition parts
When you did PCV, did you replace all those vacuum hoses? A leak can easily cause all this brouha...

Belated welcome to MVS, too!

GDiode · Post by **GDiode** » 28 Jun 2015, 16:56

Still the same. I changed the plugs with AC Delco copper, I didn't have a .028 gapper. Mine had .030 and .025 so I made do adjusting so it wouldn't go through .030. I cleared the codes before I started the job and will go out and see what it throws now. Next I'm going to try the cap and rotor from my parts car. The current wires on my duahghters are Bougicord wires.
Abscate- I only received the PCV kit I hadn't run installed it yet. That was what I was going to do this weekend.

Post by **rspi** » 28 Jun 2015, 20:42

What codes came back? Could be a fuel pressure problem. When my car ran out of gas once (on a slant) it threw about 7 codes.

Post by **Volvofan94** » 28 Jun 2015, 21:20

It may be a torn intake manifold gasket on cylinder 5. When the engine runs at idle do you hear a hissing (similar to a vacuum leak) sound where the IAC valve is located?

The link below may be able to point you in the right direction.

https://www.matthewsvolvosite.com/forums ... =1&t=68306

Good luck!

-volvofan94

GDiode · Post by **GDiode** » 09 Aug 2015, 18:32

Sorry all for the long pause between posts. This is my daughters car and since I couldn't get it running properly I had to focus on our other 850 that was running good but needed the TB changed since we have never done it in the 10 years that we owned it. So that's done thanks to Robert's videos and the cam gear locker for the added piece of mind.
So I got the codes cleared and these are what it shows now.
3-2-5 memory failure
5-4-3 misfire at least one cyl.
5-4-5 misfire at least one cyl., 3-way cat. damage
5-5-3 misfire cyl. 3, 3-way cat. damage
1-2-1 MAF sensor signal
I removed each spark plug wire while it was running before checking the codes and cyl. 3 was the only one that didn't change how the engine ran.
I then swapped that spark plug wire with one off my parts car. No change. I am getting spark from that wire.
Could it be an injector gone bad?

Post by **erikv11** » 09 Aug 2015, 20:17

It could be an injector, it could be a burnt valve.

You can test the injector by swapping them around, like you would do with a plug or a plug wire. Just be careful to not ruin or lose the o-rings and sealer rings on the injectors. If you want to test the pulse to the injector you can swap the connectors around, the injectors all fire at the same time on an 850.

Burnt valve you can test for by checking compression.

Post by **j-dawg** » 09 Aug 2015, 21:44

Sounds like you've isolated cylinder 3, but it's worth checking fuel pressure. I'm having similar problems (rough idle, low power, sounds like a burnt valve, MAF code, lean code, EVAP code). I checked fuel pressure today and it was 15psi.

It takes a very short time to test, and it's free if you rent the tester from a parts store, so it's worth a shot. Might as well do it while you're testing compression.

Post by **abscate** » 10 Aug 2015, 02:50

Compression test , all cylinders. Fingers crossed.