Vapor Trails: code FD, evap valve stuck closed

[m3f_Jrrrrrrr]

For the past several weeks I have been dealing with a regular CEL and accompanying Peake "FD" code. In case one doesn't know, that code states that the evaporative purge valve on the charcoal canister housing is stuck closed. Needless to say, I am sick of resetting the CEL every 2 drive cycles, but can't shake it off.


Facts:

1. It comes back every second run cycle (start engine, drive, shutoff engine) when that run cycle involves at least a short trip on the freeway (5th gear).

2. When I am only driving around town, it can take a number of run cycles to reappear (4-6).

3. If I ignore it, the code and CEL will go away after several run cycles, but always returns within several more run cycles.

4. Both the original purge valve and the replacement I got ARE NOT stuck closed and open smoothly with 12v applied across the terminals. They also close when 12v is taken away.


What I have tried so far:

1. Replacing the valve (no joy).

2. Applying 12v across the terminals of both valves -- the plunger inside both valves open and close fine.

3. Lubing the original valve with WD-40 -- no apparent difference in its operation.

4. Testing for continuity between the ground wire on the valves harness plug and the DME terminal specified by the Bentley -- good continuity.

5. Testing for 12v at the harness plug. As per the Bentley, the valve is normally closed and should open in pulses when the DME allows it to ground. I set up a multimeter apparatus and watched the voltage while I was driving. In fact, there is varying voltage going to the harness plug.


Some random post at BFC references a BMW order that this problem is known and is caused by a too-low voltage threshold in the DME. The alleged fix is to go to the dealer and have the DME software updated. I'm skeptical because I didn't have this problem at all for the first several months I owned the car. I also don't want to dump exorbitant amounts of money at the dealer for a "fix" that no one has confirmed the effectiveness of -- and that's if the service guy doesn't just laugh at me like I have a penis growing out of my forehead.


Who has actually solved this problem? Is there any other possible silly thing I might be overlooking?

[m3f_Jrrrrrrr]

I tried measuring the voltage again at the plug (unplugged from the check valve) and received a consistent rise from a cold start to fully warmed up with a drive on the freeway.



Voltage starts at 8-10v at cold start and falls on a cycle to around 60Mv when fully warmed.



I would have to say this test is inconclusive, or just me missing something with my multimeter. Is the DME supposed to ground a full 12v through the valve when the valve opens?



What exactly is the "low voltage threshold" issue that is supposedly outlined in that mysterious BMW service notice?

[m3f_magas]

did you fix this?

[m3f_Jrrrrrrr]

did you fix this?

Unfortunately, no.


I have noticed over the months that the CEL frequency coincides with how often I drive the car -- meaning if I'm not DDing the M3 and drive it 2-3 days a week, the CEL may only pop up every 2 weeks.


I really suspect there is a silly issue with the DME, but want to exhaust less difficult options before I investigate that. I have not closely inspected the lines or the fuel tank pressure sender yet, and that's my next move:


http://realoem.com/bmw/showparts.do?...14&hg=16&fg=10


For better or for worse, though, simply scanning for codes and resetting the light takes less than 3min, so my incentive to tackle this issue isn't that strong right now. I would definitely post a solution if I found one, because this seems to be a pretty common issue for OBD-2 cars and there are very little in the way of solutions to this issue reported.

[m3f_magas]

Damn think we have the same mysterious PITA problem.

Think I may just buy a new Evap shut off valve. My light comes on between 50-150 miles.

Same peake code.

99 m3 150k miles

[m3f_Jrrrrrrr]

Damn think we have the same mysterious PITA problem.

Think I may just buy a new Evap shut off valve. My light comes on between 50-150 miles.

Same peake code.

99 m3 150k miles

My 99 also has about the same miles.



Replacing the Evap-shut off valve (16131184235) is a good first course. It's not too expensive new, and used is about $0.00 on OBD-2 e36 cars you would find at a wrecking yard:



http://realoem.com/bmw/partxref.do?part=16131184235



Regardless, I would be sure to test the basic functionality of both the existing and replacement part with 12v applied across the terminals. The valve has a plunger inside that moves up and down in its housing with 12v. IIRC, it is normally closed and opens when the DME grounds the circuit. You can replicate this function with a 12v battery and test wires. It should move up when you apply the 12v, and immediately return to its original position when you remove the power.



Replacing this valve didn't work for me, but I have read about it working for others, so YMMV on this one.

[m3f_magas]

After getting a peake took and finding the "EVAP shut off valve stuck closed" error, I removed it and checked it. Well I took a good look at the evap shut off valve, tested it and it worked fine. It was cycling and allowing gases in. Maybe the solenoid was stuck? Only other thing I did was checked the gas tank cap. and turned the seal inside out.

Then the light went off!... usually it would only go for 50 miles. This time it stayed off for 500 miles.

Now my codes are

Table 11

08 Air Mass Sensor.


WTF. This is a new code now. I also just cleaned my MAF sensor. Wondering how accurate these damn codes are. Next step will be to get a new one. In the mean time I just reset the code and bought a new gas cap.

Will let you know how it goes. I am sick of this damn CEL.

[m3f_magas]

Gonna try this now to verify



http://www.ehow.com/video_5225929_ma...ensor-bad.html

[m3f_Jrrrrrrr]

I believe I have found a lead in regards to solving this problem.


I've been DDing the 36m again, and of course the FD code is popping up regularly as I described. This is accompanied by a very intermittent (2-3 months) "e6" from the same table 11 of the peake code -- the "e6" being a "slow response time" code for the precat sensor on the cylinder 4-6 exhaust manifold. The regular FD code is getting annoying, so I am now determined to solve it. The o2 sensor issue is on my maintenance radar and I plan to address that fairly soon as well.


Anyway, I searched more and thought to look at the fuel evaporative valve in the actual engine bay. On my car (11/98 build) it is located on a bracket off of the intake manifold (as opposed to other OBD2 owners who report it being attached to the driver-side strut tower):





The access is ridiculously easy. There is a hose from the trunk area that clips into the side. The hose on the bottom runs to the intake manifold. Pressing the horseshow clip easilly allows the hose to pop loose -- the hose itself simply clips onto the valve and doesn't come off unless one presses in on the horseshow clip:








The next day I head for my garage, I plan to do the following:


1. Test this engine-bay valve for functioning using the 12v test.

2. Test for airflow through this valve in conjunction with the 12v test.

3. Test for blockages in the blue supply hose between the trunk area and the engine bay.


It looks like this valve is P/N 13901744150 and is around $80 new, so if mine fails tests, I will try my luck with one from another OBD2 e36, or e39 at the scrap yard.

[m3f_Jrrrrrrr]

Update:



Still no joy after testing that purge valve today. For the record, I did the following:



1. Tested for functioning of the purge valve -- it opens with addition of 12v.

2. Tested for airflow through that valve with addition of 12v, completely open.

3. Tested for blockage in the blue feed line with my mightyvac vacuum tester -- no vacuum achieved which leads me to believe there is no blockage in the line.



At this point, because the shutoff valve on the carbon canister in the trunk functions fine, I have to move on to inspecting the fuel tank area and the lines that come from there to the canister in the trunk.



It truly amazes me that there are so many people reporting this issue with almost no resolution reported.

[m3f_hpde36m]

I have the same damn FD code on my 99, but I haven't had the time or desire to track it down.



Mine seems to have a little different symptoms than yours... I have pressure building up in my gas tank to the point where it will release like air being let out of a balloon. I noticed this after I filled the tank up one day and the car was sitting in the sun. I was standing there talking to someone and heard a loud 'PFFFFFFF' sound and could see the fuel vapors venting from the gas cap. I recently took the right side rear wheel well cover off and inspected the vacuum lines. There are a bunch just hanging there not connected to anything. I am in the process of trying to find a picture of what is supposed to be connected where so I can hook everything back up how it should be.



What I do know is that the ECU only performs the evap test if the tank is below 3/4 or above 1/4. So for inspection purposes, if you keep the tank topped off it will not throw the code. This doesn't actually 'fix' the issue though, only keeps the light from coming on.

[m3f_Jrrrrrrr]

I have the same damn FD code on my 99, but I haven't had the time or desire to track it down.


Mine seems to have a little different symptoms than yours... I have pressure building up in my gas tank to the point where it will release like air being let out of a balloon. I noticed this after I filled the tank up one day and the car was sitting in the sun. I was standing there talking to someone and heard a loud 'PFFFFFFF' sound and could see the fuel vapors venting from the gas cap. I recently took the right side rear wheel well cover off and inspected the vacuum lines. There are a bunch just hanging there not connected to anything. I am in the process of trying to find a picture of what is supposed to be connected where so I can hook everything back up how it should be.


What I do know is that the ECU only performs the evap test if the tank is below 3/4 or above 1/4. So for inspection purposes, if you keep the tank topped off it will not throw the code. This doesn't actually 'fix' the issue though, only keeps the light from coming on.

The DME performs the evaps tests very early in the drive cycle (first 20-30 seconds) and the gas tank level has nothing to do with the "FD" code being present.


I recently inspected the liquid/vapor separator behind the passenger-side wheel and found every line intact and in great visual shape. I did not attempt to test the fuel-tank-pressure-sender, which is a likely culprit in the "FD" code, because I do not have the connector pigtails on hand to connect to the wiring or sender. The pressure sender is a likely culprit in the "FD" code, because a pressure reading below specs will trigger the CEL. What I did find while inspecting the liquid/vapor separator is a noticeable rattle while moving the assembly in my hands. I intend to inspect the rattling liquid/vapor separator, the actual charcoal canister, and the fuel-tank-pressure-sensor further. If that doesn't work, I'll just have to look into a DME reflash as per the BMW TMS into this specific code issue.


For the record, my CEL issue has moved on to the CEL no longer illuminating as it did before, but the "FD/OBD-2-'253'" code still being present after every run-cycle upon scanning with my Peake tool. The CEL has infact not illuminated for around 10 days at this point, oddly enough.


Read these OBD-2 BMW fuel-Evap-diagnosise documents I found at BFc:

[m3f_Jrrrrrrr]

This issue if still present, though it is throwing codes much less often. By that I mean that the CEL doesn't show up but once every 4 days or so. The interesting this is that the "FD" code is always present upon scanning with the peake tool after a day's drive, but is throwing CELs less often.



At this point I am considering a DME reprogramming, because I'm pretty certain nothing is wrong with my evap system and throwing parts at the problem is stupid, but am laying off until I need to get the car smogged again in 6 months.



This has to be one of the great OBD-2 e36 mysteries that is full of mystery and conjecture and little substance -- hence this thread.

[m3f_magas]

My next move is bulb removal

[m3f_Jrrrrrrr]

My next move is bulb removal

* don't do this.