´96 850 engine struggles

[Teddy1975]

Hi Robert.

The exhaust including cat works, as in not clogged. I'll check the timing, I hope the timing belt hasn't jumped a tooth or two as I can still remember the many "spicy" words I had to use when installing it.

I'll look at it when I get the new TPS. Just got a tracking notification from UPS that it'll be here on Thursday. The package is supposed to weigh 6.5 kg or 13-14 lbs. I wonder if they put a lot of wrapping around the new TPS or they sent me a wrong part, will just have to wait and see. I mean 6.5 kg, that's about the total weight of intake manifold with TB on it.

I still can't wait for the day when I can, hopefully, get in my car and drive it out of the driveway!

/Teddy

[Teddy1975]

So, I put in the new Bosch TPS, reset the codes by holding the ground cable against the positive cable and it didn't make the engine run any better.

Read out two codes:
1-2-2
3-1-4

3-1-4 should be for the camshaft pos sensor, which I'm sure if gone bad could be the root cause of all the problems. At least the TPS code has vanished.

Does anyone know what the 1-2-2 code is? The description says "Air Temperature sensor signal absent or faulty" but what sensor is this specifically?

Thanks,
Teddy

[whilst]

Does it run strong when cold?
Or, only after it warms to operating temp?
Have you tried disconnecting the airbox hot/cold flap actuator> so it is always to 'cold air'?
Jeff

[Teddy1975]

Hi Jeff.

Thanks for the suggestion, but unfortunately it isn't just a matter of cold or hot air. It's more a timing issue, backfiring etc, which hopefully is only caused by the CPS being faulty. Oh, on another note, the actuator in my car for some strange reason does work. The flap opens gradually more to the 'cold' side the more throttle it gets and at WOT the flap is fully open to the cold side. I noticed it when I tested other things out and was mystified by the flap moving according to throttle position.

[Teddy1975]

I had to wait for a week for the new CPS to arrive, spent 10 mins to take out the old and put the new in and about 3 seconds to realize replacing it didn't do the trick, apart from clear the code.

I took off the timing belt cover and the timing marks I used when I replaced the timing belt are all right on the dot.
I couldn't get a good picture of the crankshaft mark, but it's where it's supposed to be.

20170721_152118.jpg (5.11 MiB) Viewed 1095 times

I recorded a short video of the behaviour, please disregard the nasty whine. It's from the power steering pump and has sounded like that for the 1½ years I've owned the car. It's on the to-do list but quite far down on it as it works, just noisily. You should be able to hear the struggling engine as soon as I touch the throttle, however.

There are now again no codes, just the 1-1-1.



It idles better warm but that won't get me too far out of the drive and the jokes of driving an old Swedish tractor would be too fitting.

[hausmeister]

@Airbox:
I don't think this is correct. Mine is vaccuum actuated and opens up according to temperature. Maybe you have a vacuum leak somewhere? That could also explain the high idle and crap running.

@Cam Pos sensor:
I had that fail once. Car would not start. You had to try multiple times, and with luck it would start. It also set a code within reasonable time.

I know the feeling. I have had the problems with the intake temp sensor for more than one year. They were not so bad at first, and very hard to get a grip on. Sadly the ECU was not very helpful. It olny set a code after I replaced the coolant temp sensor.
Now I have forgiven the car, it runs perfect and is reliable as ever. But I am not sure if I will go to the same effort for the next issue. Without a good obd2 it is very hard to diagnose them.

The video is not available

[Teddy1975]

Just a quick update on this.

The problem seems to have been revolving around the leftmost pinbolt near the EGR pipe coming out of the exhaust manifold. Or rather, the pinbolt that was sheared off about ½ cm inside the aluminum before I even bought the car. The manifold wasn't held tight to the engine causing exhaust gasses to evacuate the system before they got past the lambda sensor and false air was sucked into the system through the crack between engine and manifold. All of that caused the engine to run rough. I know someone said that already, this is just to confirm that is what was wrong.

I finally bit the bullet and took it to the indy shop who had my car in for the insurance paid body repairs. He told me they'd try to drill out next to the pinbolt, pry it out and put in a new pinbolt and fix it in place with some heavy grade chemical metal designed for ship's engines. They've done so with luck on two other Volvos this year alone.

Unfortunately, the pinbolt on my car, being the very last one of them, sat in a position (almost dead center of the car) where they couldn't get to it with the engine in place. So after a talk with him, I've decided to go ahead with an engine swap. For now, he has sent a request to Volvo in Sweden for a good used engine. One, that in his words, will fire up on the first crank after being installed, otherwise he won't even attempt it.

Though his two mechanics have spent a lot of time, in between working on the other cars they have in the shop, I'm only to pay for two hours for their trouble. I asked about the bill for swapping the engine, asked if it would be around 10 hours' work. For the swap, he told me, he'll work out a good price and it would certainly be less than 10 hours I'd have to pay for, even if they may end up having to spend more time on it.

So yeah, it's been a long travel to get to this point and it'll end up costing a lot more than I would've hoped, but it seems I will get the car back in about a week, with an engine that'll run better than the old one ever has while I've owned the car. (Note to self, trying to fix stuff you have no knowledge of may cost more than just taking the car to the shop.)

Thank you all who have tried to help me with the troubleshooting and fixing it. Oh, by the way, the weld on the manifold I did? It held, but as soon as I installed it, the manifold cracked in another place, 2 inches from where I had welded it. If anyone is considering welding a crack in the cast-iron exhaust manifold, it can be done. I'd advice to remove it from the car and do all the preparations for the weld, put it back in the car and weld it while it's firmly attached to the engine to prevent it from cracking when you later move on to install it.

/Teddy

[VolvoMis]

Hey.
Sorry to bump in like this, but wanted to say Thank you for sharing your experiences with the exhaust manifold. Just found a crack in mine at the exact same spot, which caused the most annoying idle ever.

Congrats on your New engine. May it run forever.

Siw.