All,

I've been fighting this thing for quite some time now and it appears I've circled back. Ugh!

Any ways, this morning, before I did anything I had the following codes:
P0410, P0301, P0300, and P0305.

The car was running like crap and you could feel the misfires, it was awful.

So I replace the CAM sensor and while I was in there I replaced the CAM seal as well as it was leaking.

Took the car out for a test drive (about 10 miles, 15 mintues) with very little to no stopping and no code were pending. Parked the car figured the problem was gone.

Took the car out about an hour later, and all of a sudden I now have a pending P0172 code. This drive was about 20 miles, and took a little over 20 minutes to complete. Before I get home the pending code becomes a real code, and when I started the car up later in the day, I now have a new misfire code, believe it to be P0301. When I did get home from this drive, I checked for vacuum at the FPR and I had none, so this is why my car is running rich, but I do not believe it to be the vapor canister purge valve as I tried a brand new one and it did not make a difference, it acted just like the original one. Sometimes the valve works, sometimes it does not. I'm starting to think flaky ECU, but can't prove it. Thoughts????

In addition to this I now have a better understanding of what it will take to set the pending code, or at least this is what I believe is happening from what I've been reading today. While driving at speed or accelerating, the vapor canister purge valve gets turned off so as to supply maximum pressure to the fuel rail. When you are idling the vapor canister purge valve gets turned on so as to lower the pressure at the fuel rail, and thus keep the proper 14.7 to 1 ratio that is needed to burn the fuel efficiently. However, in my case, this is not happening all the time as is evident when I remove the vacuum line to the FPR when I'm idling, sometime's I have vacuum, sometime's I do not, so here in lies a problem, and the question is why is this happening sometimes at idle the vacuum is there and other times I have nothing. Inquiring minds want to know as I'm getting close to taking this in to see the man.

Thanks in advance,

Matt
--
1989 - 245, 1990 - 245, 1991 - 245, and 1993 - 245

So after much whaling an knashing of teeth, the car let me stranded, so off to the shop it went as I had just had enough with it.

The reason for it leaving me stranded was that the coil had failed. That was a pricey fix, but at least it is now running.

While it was there I had then diagnose the P0172 code. Their diagnosis was that the intake manifold gasket was leaking. I didn't believe it, but they saved it for me like I had asked them to, and wow, I couldn't believe it.

Now I had replaced the PCV system two years ago, and part of the process is to replace the gasket since you have to take the intake manifold off to access the stuff underneath it.

Any ways, I need to post a picture of it so that you can see for yourself, but 1) I believe somehow I put it in backwards, and 2) some how it got folded over at one spot causing the leak. How this got folded over I do not know, but that is what caused the vacuum leak. What I have yet to figure out is why did this not show itself sooner. That is what I'm really trying to understand.

Anyways, there you have it. The car is now running great and I plan to drive the snot out of it.

Regards,

Matt
--
1989 - 245, 1990 - 245, 1991 - 245, and 1993 - 245

Hurry up and do the SAS delete.

The FPR has a couple of vacuum lines, if I remember correctly none go to the SAS.

Check the elbow for the FPR vacuum line at the intake manifold. Mine died internally when it got warm. I used a piece of silicone hose, making a 360 to get the right angle shape and keep it from kinking or collapsing.
--
Keeping it running is better than buying new

SAS isn't the problem any longer.

The FPR has a shared vacuum line with the EVAP canister and nothing else.

The line from the intake manifold to the vapor canister purge valve has already been replaced and is fine. The line from the vapor canister purge valve is the one that snakes down and back to the FPR.

So let me ask you this KlausC, on a cold engine (open loop mode), will the ECU keep the vapor canister purge valve open or closed at idle? Also, on a warm or hot engine (closed loop mode), will the ECU keep the vapor canister purge valve open or closed at idle?

Thanks,

Matt

Yes, but not always?

https://www.matthewsvolvosite.com/forums/viewtopic.php?t=49640
--
Keeping it running is better than buying new

KlausC,

Thanks for the link. I believe it confirms my suspicions, and I quote.

''The ECM will operate the purge valve after idling for a brief time when the engine is in closed loop.
ECM will operate valve at a low percentage initially and the fuel trim correction will be paused so the oxygen sensor can be used as an indicator of whether there are vapors in canister or not. Rich indicated by sensor will cause ECM to continue to operate the purge valve for 40 seconds +/- , lean indication will stop purge for a time until ECM repeats canister monitor. Canister monitor continues while idling and whenever vapors are detected purging will commence.
Purge valve should be sealed until ECM provides ground. Purge valve is provided 12V feed whenever injectors and other components of fuel system are powered.
The canister vent is controlled through a canister vent closing valve. Vent is opened except when vapor loss testing is going on.''

On initial start up the ECM keeps the purge valve closed because you are running open loop. While driving it may nor may not open it. Bottom line, it depends.

However, once you are closed loop, and come to a stop and idle, the valve will be opened to drop the fuel rail pressure so that the O2 sensor does not detect a rich condition. This is where I have screwed up. On the brand new sensor I only tested in on cold start up not knowing what I know now, so I now have another brand new sensor coming to replace my original to the car one. If this does not fix it, then I have two options: 1) buy a three day subscription to Vida and find the troubleshooting steps so that I can walk through this properly, or 2) pay the man to find the real problem and suck up the cost. Not sure what I'll do when I get there, but at least I have options, and options are always good to have.

Thanks again,

Matt