I pulled the A2: 231 on my 94 850 turbo wagon. A few weeks ago I noticed a lot of hesitation under load and the engine started to misfire in every cylinder. So, I gave it a complete tune up - replaced all of the vacuum lines (some were bad), new plugs, wires, cap/rotor, coil, fuel pressure regulator, and fuel filter. Car is running great at idle, but it still seems to bog down under load. If I give it gas it chokes and the stock boost gage doesn't want to get past 12 or 1. Is my Turbo going out? Is it running rich because there isn't enough air? Could it be the MAF? Also, I stupidly replaced the fuel pump a few months ago with an aftermarket pump from Groton - Could it be a bad pump? Where should I start? Is there a vacuum line that I may have missed?
Astroubled as I am about this, I just replaced all of my suspension, so the new comfort from that is keeping me from being to upset - what a difference new suspension gives.
Thanks,
dedicated volvo driver

 

Could possibly be a clogged air filter, or a faulty O2 sensor. Might want to givea look-see in that direction

 

Thanks for the reply. I changed the air filter, too when I did the tune up. I also replaced the whole exhaust system and both O2 sensors two years ago. However, I have had an exhaust leak inbetween the O2 sensors where the pipes connect. Could that leak be causing the O2 sensors to act up? I have a correction on the last post I havebeen watching my boost gauge and it does seem to be functioning properly and I can hear the turbo whistle under boost when the car seems to die/hesitate. I read on here that to test the MAF I can disconnect it and try to start the car and if it starts then the MAF is bad - is that correct and is it always true??

Thanks,
Wes

 

I also have not been pulling any other codes since the tune up, just the 231. I would think that I would be pulling other codes if it was the O2 sensors, MAF sensor, or TPS sensor, right??

 

If it's running rich then there would be,

1. a fuel pressure issue? As in too much fuel coming in on it's own,
2. an air issue? Not enough air coming in to mix with the right amount of fuel, therefor making it fun rich,
3. an electrical issue, MAF, TPS, or O2 miscommunicating?

Okay, I guess I should wait for a Moderator now

Wes

 

231 Is long term fuel trim. (usually somekind of vaccum leak)
Maybe an intercooler hose is bad.
Maybe a bad Mass flow sensor. Can trip this code as well.
It could be many things.

 

Thanks for the response Tech. I just checked all of the vacuum lines again and I did find a cap that was bad on an unused port located on the intake hose going into the turbo where multiple lines connect. There is an electrical connection to something inside the hose there and I'm not sure what it is, wonder if it's caked with oil and needs cleaned?? I'll let you know if that was it. There was also a line coming from the manifold that curved under the air intake above the radiator. It wrapped around the battery and disappears. it had been cut at one time and someone connected the hard line with a flex tube and it seemed loose. when I sucked on the line to the manifold I sucked air, but when I sucked on the other line going nowhere (maybe EVAP canister) it was blocked. What would this line be? Also, how can I check the MAF? Thanks Tech!

Wes

 

Also, what does long term fuel trim really mean? Is it constant, over the "long term" or is it just on the "upper limit", meaning under load?

I love learning about my car on here! Thanks for the education.

 

The one that goes under the battery tray might be the cruise control hose.
The electrical connection in the big hose just before the turbo I believe is like a heater. Have never found any info that tells exactly what it is for.

Are all the hoses to the inter cooler and throttle body really good?
Also if any feel really soft they might be sucking shut and cutting off air flow to the throttle body not allowing the boost to build up.
You can check the MAF with a meter but I don't have teh specs.

 

NO WAY! Yes, the hose that goes into the throttle body is really really soft and I ment to post that and forgot. Is there anyplace other than volvo to buy those hoses. the wierd 90 degree hose that connects to the idle air control valve had a crack and I super glued it shut - seems tight. I did that because I couldnt' find anything to work. where would a good place be?
Thanks again,
Wes

 

http://www.fcpgroton.com/product-exe...ategory_id/216

That looks like a pretty good price.

 

nice, I didn't even see it on there. Thanks, Tech. I'll let you know when I get it. Enjoy the holiday.
Wes

 

You enjoy the holiday as well.

 

Congrats on your 20,000th post

 

Well done Tech, well done.

 

THANKS!!!

 

20,000 ??? Good Lord that'sa alotta typin'[sm=happy046.gif]

And one big Brain[sm=icon_ladiesman.gif]

[sm=icon_cheers.gif]

 

Tech!!!

Okay, so I got my new intercooler lines today and installed them. I reset the codes and drove it today and it seems worse!! As soon as I give it a lot of gas it will barely move, the rpms go high and the boost goes high as if I should be taking off but i don't go anywhere and it won't shift into the next gear until I let off the gas. As long as I baby it very slowly I can drive fine, but as soon as I put the pedal down a little it seems to stay the same speed while the rpms, boost rise and I now I'm wasting a ton of gas. I drove to chicago this weekend and got 18 mpg!!! I'm pulling 231 AND now I'm pulling 452, 454 (misfire in cylinders 2 and 4, Emission levels exceeded) and 543, 542 (misfire in at least and more than one cylinder, Emission levels) codes. What is going on?? I've been dropping a lot of money on my car and can't seem to fix it, I'm about to flip out. I'm driving to Maine in two days and I have to get this thing fixed, please help.

Wes

 

Now I can't get it to start. I turn it over and it starts and shakes and misfires and then dies.

 

Update. I went out and got the car to start, I'm not sure why it was giving me problems earlier. I tried spraying starting fluid around all of my vacuum lines and hoses to find a leak and nothing. I figured as much since I replaced them all. I also sprayed around the injectors and manifold, everywhere actually and nothing. I also just tried starting my car with the MAF disconnected (I read on here that is a way to check it) and it did start and ran for a few seconds before it started to choke. Is my MAF bad, would that be causing these problems? I'm not pulling a 121.
Wes