lookforjoe Posted March 29, 2015 Report Share Posted March 29, 2015 The other thing that hasn't been discussed here is the MAF electrical connector. The pins themselves can deteriorate, and the harness is supposed to be looped back on itself with a tie wrap to prevent fatigue on the wiring. Either one of those could be your problem. I also believe if the sensor you bought is Bosch & not KO, then it makes no difference that it wasn't in a blue box. Link to comment Share on other sites More sharing options...
3gGT Posted March 29, 2015 Author Report Share Posted March 29, 2015 This is the Bosch MAF, with the exact same P/N that was on my original part and I purchased the car new. One thing I always do is apply silicon grease to any electrical connectors when replacing parts, including the MAF sensor connector. Hopefully this is not causing any problem. I have done this on all my cars for the past probably 30 years with no problem that I recall. When I get back in town I'll have to doubt check vacuum, PCV valve and the flame trap. I have a vacuum gauge, but if you want to test with a smoke machine, don't they cost a bunch or is there some way to do this without having access to the the high dollar equipment? Link to comment Share on other sites More sharing options...
troyhyde Posted March 30, 2015 Report Share Posted March 30, 2015 Please check your fuel pressure after a stall - depress the Schrader valve on the fuel rail. Trickle? Steady spray of fuel for 10-20 seconds? I think your problem is fuel related, these MAF's are plenty tough and reliable. Link to comment Share on other sites More sharing options...
3gGT Posted April 7, 2015 Author Report Share Posted April 7, 2015 Drove ~150 miles this weekend and it was stalling worse than ever. Pulled over and pulled the MAF electrical connection, but it still seemed to run odd and idle high most the time. Tonight I got ready to clean the flame trap and vicinity, when I noticed that the intake hose was cracked and offset a bit. Approximately 60% around was cracked, but barely noticeable. I've ordered an OEM part from FCPEuro along with a flame trap kit. More than likely this is the real problem I've been having. I suppose it has been cracking more and more and thus the symptoms have become more frequent and worse. I'll update the forum once I get the parts on and test it. Thanks! 3gGT Link to comment Share on other sites More sharing options...
erikv11 Posted April 7, 2015 Report Share Posted April 7, 2015 The actual flame trap disc, the little one with the holes in it: just throw it away, all it does is get clogged up. Link to comment Share on other sites More sharing options...
3gGT Posted April 7, 2015 Author Report Share Posted April 7, 2015 Good to know. I used some piano wire to get all the holes cleared. Link to comment Share on other sites More sharing options...
troyhyde Posted April 7, 2015 Report Share Posted April 7, 2015 Cracked intake hose, I think you've found it! Congrats. Link to comment Share on other sites More sharing options...
BlackBrick Posted April 7, 2015 Report Share Posted April 7, 2015 vacuum leak! Link to comment Share on other sites More sharing options...
3gGT Posted April 15, 2015 Author Report Share Posted April 15, 2015 I received the intake pipe and flame trap kit yesterday and installed and tested the car. Believe it or not, I still have the same problem of stalling when at or near idle when stopped or close to stopped. I pulled the MAF connector and it still acted like it wanted to stall. I'll probably put a vacuum gauge on there next. I still need to see about checking the PCV valve. It seems like it is in a difficult place to get to. I wonder if the IAC could be going bad. I had cleaned it a couple of weeks back. Link to comment Share on other sites More sharing options...
erikv11 Posted April 16, 2015 Report Share Posted April 16, 2015 There is no PCV valve on these cars. There is a hollow box (oil trap) under the intake manifold, and then a few vacuum lines. One goes from the oil trap box to the flame trap housing at the intake, another from the box to the top of the valve cover. In looking at vacuum leaks did you check the vacuum elbow from the passenger side of the intake manifold to the flame trap? That one commonly rots and falls off. Link to comment Share on other sites More sharing options...
3gGT Posted April 20, 2015 Author Report Share Posted April 20, 2015 The vacuum label under the hood writes out (T-PIPE PCV), but I didn't see one, same as you mentioned. In looking for the vacuum leak, I pulled the small vacuum line off the flame trap and the plastic line was brittle and broke. I replaced it with a snug fitting rubber hose. I tee'd in to test vacuum here and I'm only showing 5", which seems very low. My vacuum gauge indicates 20" + would be normal. I tried using carb cleaner to locate a vacuum leak, but so far no luck. The stalling has steadily gotten worse and has become a real problem and I don't think I can have my wife drive it any more. I didn't find the vacuum elbow on the passenger side of the intake manifold. I will need to look some more today. Anyone able to verify what the vacuum should be on the 95 850 NA?I've attached the vacuum diagram.Thanks! Link to comment Share on other sites More sharing options...
3gGT Posted April 29, 2015 Author Report Share Posted April 29, 2015 I was wondering if someone could check the amount of vacuum at the connection where the small hose goes to the flame trap. I'm tee'd into that connection and I only show 5 Hg, but if I pinch that small hose going to the flame trap, vacuum goes up to 18-19 Hg. Is that normal? Link to comment Share on other sites More sharing options...
3gGT Posted May 10, 2015 Author Report Share Posted May 10, 2015 Connecting to the vacuum tee on one of the capped ports, I read 19 Hg, which seems ok. I'm still not sure about the small vacuum line going to the flame trap and why that reads 5 Hg and if that is normal or a red flag. On my particular model, there isn't any vacuum hose on the passenger side of the intake manifold. There is a flat spot, where some Volvo 850 models have a vacuum port and attaching hose. Looking from underneath the car, as well as possible, all the hoses to the PCV systems look ok, but I may end up removing the intake to get a complete view. My car had relatively little build up of dried oil gunk on the flame trap piece with small holes, so I'm not expecting the PCV system to be clogged. Link to comment Share on other sites More sharing options...
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