Poor performance under load

robsmed · Post by **robsmed** » 10 Jul 2012, 16:52

1996 850Turbo.
I have just replaced the PCV box & plumbing and replaced worn & deteriorated vacuum lines. I had been getting a "bad MAS" code on the scanner and a failure to idle. The new MAS made no difference, but identifying and replacing bad vacuum lines did. I also decided to tackle the PCV task as well.

Got it all back together using the IPD kit, but now the engine bogs down or hesitates badly as I try to accelerate past 40mph or so. Almost feels like cutting out. At idle, all is fine. I have checked spark plug gap and noted all is good, well within spec.

I considered possible crossed vacuum lines at the turbo, and swapped them around. No difference noted.

Any new suggestions concerning what might be causing this would be appreciated.

Zdadgeezer · Post by **Zdadgeezer** » 10 Jul 2012, 17:25

Although I do not have an 850 my codes also pointed to a possible bad MAS among other things. I identified that my fuel pressure(main in-tank pump) is most likely the major culprit. I also had replaced my vacuum lines due to deterioration. I found that many of these year/ models share the same bugs if you will. So don't overlook a thread if it is not specific to your car. My car has sluggish acceleration and wouldn't maintain a steady RPM above idle also throws a code with several possibilities. That's why I checked your thread to see what you had done.
Good Luck , If I find anything similar I will send it your way.

robsmed · Post by **robsmed** » 10 Jul 2012, 20:04

I appreciate the input. I wish the condition would throw a code, but it does not. Very frustrating.

Post by **jmailloux** » 10 Jul 2012, 20:09

I will have to agree with Zdadgeezer.....You may want to check the in tank fuel pump. My V70Rm (1998) wasn't quite that bad, but it had some similar issues, and the new fuel pump fixed it. I had a mechanic do that job, though, and wasn't cheap, unfortunately.