TRE-340 conversion

[rvaughnp]

As of - 11/23/2013 Working fine.

Unfornately, the first thought process didn't pan out... the good side of it that i am working out the bugs before you get started.
I will edit this thread as things unfold. I will try to remember to date and state changes as well.

10/3/2011
- Took off the rubber/foam sleeve. Added hose clamps.
- Realized that the TRE-340 has a check valve in it (have pic) but it didn't work; even after installing a spring to force in shut upon no flow.
- Installed fuel resistant fuel line. Part number below.
- i will be adding an after market check valve.

10/8/2011
- Installed check valve where old fuel pump and filter were.

(Edit)I just have the issue of the slow pressure drop upon shut down. With new check valve i still get a pressurte drop, but the drop is about 1# every ten minutes. The pump runs so quite that you don't know it is running unless you have the carpet up in the trunk and you put your head inside the trunk.

Thanks Chris, for your input.

Items needed:
- TRE-340
- 3 Bar fuel regulator. I used 0280160249
- BMW check valve 16149068988
- Solder, flux and torch or solder gun
- 3/8” mip x 5/16” barb fitting
- A couple of 5/16” hose clamps (some come with the kit)
- 18 ga. and 20 ga. heat shrink, about 4” long
- (4) - small zip ties
- Gates 27097
- (1) 1 1/2" hose clamp

First, take fuel panel in trunk off. Located under the mat, assuming you have one, to the right (3 screws).
Next, disconnect the two plugs. The plug towards the tail lights is the fuel gauge plug, the one closest to the rear seat is the pre pump power.
Next, take the 6 bolts and 4 screws loose. Do not pull the sensor out first as one of the nuts or bolts could easily drop into the tank.
Next, lift the sensor out.
http://forums.bimmerforums.com/forum/picture.php?albumid=1965&pictureid=10792
Next, pull out the pump assembly.
http://forums.bimmerforums.com/forum/picture.php?albumid=1965&pictureid=10793
Here is the assembly as it came from the factory.

Here is the factory pump and the TRE-340 side by side and a pic to get an idea of how it will fit next to the factory pump while maintaining the factory distance to bottom.
http://forums.bimmerforums.com/forum/picture.php?albumid=1965&pictureid=10794

Keep in mind when putting all this back together… you want the sensor to go back in.
http://forums.bimmerforums.com/forum/picture.php?albumid=1965&pictureid=10795
Keep this area clear so that the gauge will slide through.
http://forums.bimmerforums.com/forum/picture.php?albumid=1965&pictureid=10796
Unscrew this screw.
http://forums.bimmerforums.com/forum/picture.php?albumid=1965&pictureid=10797
Unscrew this screw.
http://forums.bimmerforums.com/forum/picture.php?albumid=1965&pictureid=10799
Pry up screw bracket.
http://forums.bimmerforums.com/forum/picture.php?albumid=1965&pictureid=10817
Pull pump from assembly. Notice the clean spot were the rubber was around the pipe…
http://forums.bimmerforums.com/forum/picture.php?albumid=1965&pictureid=10800
Cut wire in half.
http://forums.bimmerforums.com/forum/picture.php?albumid=1965&pictureid=10801
Cut pipe off on that line. If you don’t feel too comfortable and think that maybe it’s too close to the cross bracket then get a small hose bib clamp, two should have come with the kit, and place it over the metal tube to be cut against the cross bar and add about an 1/8”. You want to make sure that a hose clamp can fit over the rubber tube without “over hanging” and pinching the rubber on the edge of the cut tube.
Do not use the hose that comes with the pump. Use the same length in this pic of 3/8” pressure tube (Gates 27097).
http://forums.bimmerforums.com/forum/picture.php?albumid=1965&pictureid=10802
This is why. It apparently isn’t for pressure.
http://forums.bimmerforums.com/forum/picture.php?albumid=1965&pictureid=10803
Next we hook up the wire.
http://forums.bimmerforums.com/forum/picture.php?albumid=1965&pictureid=10804
I unsoldered the factory wire, cleaned the contact and pushed through about 2/3rds of the connector wire. Wrapping the two ends on the other side then soldered with soldering gun. The black wire I had to use a map gas torch by heating the tube and applying solder to the tube, then heating the wire and applying solder to it, then putting the two together and lightly heating them so that the solder “gels” and then letting them cool forming a solder joint.

If you look inside the TRE you will notice a check valve inserted into the outlet side of the pump. It's just for show.lol. Mine didn't work as it came from the factory. Nor did it work after inserted a spring to force it closed when the pump was shut down. You can choose to leave it or pull it. as of the last edit, mine is in and will stay there until i need a reason to pull the pump back out.
http://forums.bimmerforums.com/forum/picture.php?albumid=1486&pictureid=10924


http://forums.bimmerforums.com/forum/picture.php?albumid=1486&pictureid=10925
I broke the "flange" bracket that held the screw for the old pump off before installing the hose clamp.
Install an 1 1/2" hose clamp.
Here is the final product.

Notice:
- Hose clamps to the inside.
- Electrical connector centered under the cross bar.
- The nut part of the hose clamp should be 90 degrees from the tube.
- The return tube was slightly bent to the outside as to not cause issue with the suction of the pump.
- Do not bend the return directly to the outside as the pump will not go back into the hole in the tank.


http://forums.bimmerforums.com/forum/picture.php?albumid=1965&pictureid=10807
You will be utilizing the notches to slide the pump through.
http://forums.bimmerforums.com/forum/picture.php?albumid=1486&pictureid=10923
http://forums.bimmerforums.com/forum/picture.php?albumid=1965&pictureid=10809
Insert gauge before installing any bolts… this will close the hole that a misguided bolt would find its way to.
Put the hoses back and the plugs back on.
Next is under the car.
You will have to remove the outside pump from underneath the fuel tank and behind the passenger rear wheel.
You may choose to also disconnect the fuel filter down there as well as it is difficult to get to and install one in the engine compartment before the fuel rail.
Now onto killing the power for the underneath pump.
Here is the feed line (larger line) and the supply line (smaller line).
http://forums.bimmerforums.com/forum/picture.php?albumid=1965&pictureid=10810
I used a 3/8” mip x 5/16” barb fitting to hook the two hoses together.
http://forums.bimmerforums.com/forum/picture.php?albumid=1965&pictureid=10811
http://forums.bimmerforums.com/forum/picture.php?albumid=1486&pictureid=10946
Cut the hose holder and pull the large hose out so that you have room to work. Install check valve kit.
Now onto the electrical connections of the pump
http://forums.bimmerforums.com/forum/picture.php?albumid=1965&pictureid=10813
Cut the two wires. The power wire has two wires so you will need to solder them together.
http://forums.bimmerforums.com/forum/picture.php?albumid=1965&pictureid=10814
http://forums.bimmerforums.com/forum/picture.php?albumid=1965&pictureid=10815
Add heat shrink to both wire and heat
http://forums.bimmerforums.com/forum/picture.php?albumid=1965&pictureid=10816
Now zip tie to the other wires above.

Done.

[eric1ono]

This sounds pretty good. Thanks for doing this. I love the idea of going to 1 pump and simplifying the fuel system.

I have a few questions:
1. How did you bend the end of the return tube?
2. Have you run this set up with a low tank of fuel? Just asking because the head pressure will be different.
3. Just double checking, the OD of the metal pipe coming down and the OD of the exit port on the fuel pump look to be quite differerent in diameter, did you do anything special to the 3/8" hose to make it work or just clamp down a good bit until it closed on the fuel pump port? Did the 3/8" hose slip over the metal pipe easily?

Sorry for the questions, just want to make sure I understand.

Thanks again for putting this together.

Eric

[rvaughnp]

1. How did you bend the end of the return tube?

Phillips head screw driver and a gentley bend.


2. Have you run this set up with a low tank of fuel? Just asking because the head pressure will be different.


I actually did run it with the reserve light on and yes it did starve for fuel. I put 2 gallons in and it ran normal.

I should state that i have an issue of her durging at around 4000 rpm. First time i rev'd that high since getting back on the road. I am hoping that is a seperate issue, as i can rev the motor in the drive and watch the fuel pressure rise to aroung 47psi.



3. Just double checking, the OD of the metal pipe coming down and the OD of the exit port on the fuel pump look to be quite differerent in diameter, did you do anything special to the 3/8" hose to make it work or just clamp down a good bit until it closed on the fuel pump port? Did the 3/8" hose slip over the metal pipe easily?



Yes. the tubing is around 3/8" and the exit of the pump is around 5/16". It really isn't that big of a step down when tightening the 3/8" hose down to the 5/16".

Sorry about the title. I sent a message to the administrator to see if it can be changed. Didn't pay attention before i sent it.

[CW6er]

Nice write-up ! :cool

Just wondering what is the black wrap on the new pump was and why?

I don't suppose you have another shot of the pump going into the tank? So there is no room for those small headed hose clamps?

I hope zip-ties don't soften or dissolve in gasoline !?! You might drop a couple of them in a jar of gas so that you can monitor them to be sure?

And I'd worry about them coming loose with the vibration (or if they soften).

[rvaughnp]

Just wondering what is the black wrap on the new pump was and why?
I assumed it was to deaden the noise.

I don't suppose you have another shot of the pump going into the tank?
I don't but i could.:)


So there is no room for those small headed hose clamps?
It would have to be really small. Do you have a part number in mind? I wouldn't ordering one and trying it. The head of the zip tie fits with just about 1mm or 2mm.


I hope zip-ties don't soften or dissolve in gasoline !?! You might drop a couple of them in a jar of gas so that you can monitor them to be sure?
I hope not either. It's one of those "wait and see" things. I plan on checking it about every other month or so anyway. It only takes about 1/2 an hour to pull and reset.


And I'd worry about them coming loose with the vibration (or if they soften).
yeah, i thought about it. But when you get to a point of no return... you say "screw it, lets see what happens."
If anyone can think of an alternative way of mounting it... I'm all ears.
Ultimately, if anyone is hesitant about having zip ties hold their fuel pump in, along with the pressure hose, then that would be something to obviously think about.

[bimas]

I think that zip ties in gasoline will be fine for many many years as long as you don't mess with them. If you wanna check them for good measure, I would always replace them while in there.

[carsnplanes]

In aviation, there are zip ties (ty-Wraps) that are fuel and oil proof. May want to look into using those.

[CW6er]

I was thinking the head of a small hose clamp might fit above and below the original mounting bracket that is welded to the return tube. Stant makes a small headed hose clamp and the pack I have lists one that extends to 2-3/4", is that enough? (I don't know, however, if the head size stays small on the larger reach clamps?)

The black wrap might take up too much space with a hose clamp, I thought it was a spacer or shim for a mounting bracket on other applications?

http://forums.bimmerforums.com/forum/picture.php?albumid=1965&pictureid=10797
(http://forums.bimmerforums.com/forum/picture.php?albumid=1965&pictureid=10797)

[eric1ono]

Another question for you (this is really more generic to the fuel system no matter the pump), after you turn the car off, is the fuel pressure supposed to drop back down or should it maintain pressure all the time?

Thanks,

Eric

[86GT635]

It should hold the pressure. I think that is the job of the fuel pressure regulator; it's operation determines how much fuel is cycled back to the tank.

[carsnplanes]

Don't let the "fuel pressure regulator" name fool you. it is not designed to "hold pressure" off line. Unlike some Bosch Fuel "Constant Injection System" (CIS) injection systems which are designed to maintain and hold pressure at a high pressure reading that varies between 30 and 45psi all time. It then has a air door that is attached to a fuel metering valve that sprays fuel to each cylinder.
Our cars just use the fuel pump to run when we crank the engine. The pressure in the fuel rail is there all the time as long as the pump is running and there is vacuum to the FPR. The electronic injectors do the work of injecting the right amount of fuel from ECU data. Fuel pressure drops off when we shut down. It may have a little residual when we first shut down until the pressure and return lines dissipate pressure.
The FPR only regulates during engine operation because of the vacuum valve inside. It either lets more or less fuel through depending on engine demand (manifold pressure/vacuum) but never completely blocks fuel.

[86GT635]

Right, but the system is designed to hold the pressure after shut down. I think that is why the fuel pump doesn't prime the system when turned to acc.1 or even acc.2, it only begins to pump when the key is turned to start. It's supposed to maintain pressure indefinitely, to prevent vapor lock.

[rvaughnp]

Mine looses pressure. BUt it starts within a couple of seconds. Can anyone verify through print or visual sight of a gauge, of their own car, that they don't loose pressure? I have tried researching this and have come up with nothing so far. With all due respect to anyone stating that the pressure should hold, i would hate to spend a couple of few hours looking for a leak to find out the regulator is made to leak down.
Ultimately it wil loose pressure from the check valve in the pump, these injector(s), the CSV, the regulator or a leak. Lets assume we could rule out the leak. The first three i believe would not be made that way from the manufacture.

[eric1ono]

I second the request on verification of whether or not a properly running car maintains or loses pressure after shut down.

I have an adjustable fuel pressure regulator on my car, and my fuel pressure drops after the car is turned off. Maybe not immediately, but fairly soon after. However I have an issue that I believe is fuel related, and I'd like to know if this loss of fuel pressure is an indication of something or if it is normal.

Thanks,

Eric

[CW6er]

Don't let the "fuel pressure regulator" name fool you. it is not designed to "hold pressure" off line.

Actually the FPR is designed specifically to hold residual pressure (not full) in the fuel rail to help prevent vapor lock (but not indefinitely, it will eventually bleed off). The FPR has a simple spring loaded diaphragm that acts as a pop off valve. When the fuel pressure matches the spring pressure the diaphragm uncovers the fuel return line maintaining a constant fuel pressure. The vacuum line goes to the backside of the diaphragm and essentially "lightens" the spring pressure. When the vacuum is high (closed throttle), the spring force is less due to the vacuum and the fuel pressure is lower. When the throttle is opened, the vacuum decreases, the spring force is higher and the fuel pressure increases, increasing the mixture.

See Pg. 7-10, Fig. 5-4 of the Bentley Manual for FPR cross section.

When the engine is off, the FPR spring loaded diaphragm closes and acts as a check valve. The Main Fuel Pump also has a built in check valve to maintain a residual pressure with the engine off.

Hmm .... This is a good question, I wonder if the TRE-340 pump has a built in check valve since it is replacing the Main pump containing the check valve? Its not a big deal if it doesn't, as there is an inexpensive external add-on check valve available.

[rvaughnp]

This one?

http://img.photobucket.com/albums/v355/dark_islight/fuelcheckvalveinstalled_2copy.jpg

http://www.ecstuning.com/Search/16149068988/
I am showing it to be $2.90.

I did research the tre-340 pump for a check valve but can't find any reference to it having one.

[CW6er]

That is the same part number I have.

[Flash635]

D'ya think the check valve would be better right up at the injector rail?

[rvaughnp]

D'ya think the check valve would be better right up at the injector rail?
No.
http://forums.bimmerforums.com/forum/picture.php?albumid=1965&pictureid=10862
As per the picture you will loose pressure behind the checkvalve. The closer the check valve is to the source, the less the pressure has to build back up.

[Flash635]

You only need the retained pressure to get the engine started, after that the pressure builds up almost instantly.
I just thought it might be better to have low pressure in most of the line while the car is sitting idle.

[rvaughnp]

There might be something to that as I believe later series of BMW's had a check valve in the regulator at the fuel rail.
I'll try it when it comes in and see if it works.

[eric1ono]

That does sound reasonable, please let us know after you've had a chance to check it out.

Thanks,

Eric

[rvaughnp]

ordered tonight. probably won't be in until end of the week.

[rvaughnp]

Just encountered another pressure issue... started the car up, after about 10 secs of turning over the starter, and she was idling pretty rough. Popped the hood to see around 20 psi.:mad:mad:mad:mad. I was swapping on the new rims so i will wait until the check valve comes in and look inside the tank to see if it blew the hose apart, as it had before. The pressure droppped off in the same way.:(

[86GT635]

There is some special submersible fuel line for those things.

[eric1ono]

Sorry to hear you having these kind of annoying issues. Glad to see you sticking it out though and working through them. Did you use high pressure 3/8" fuel hose before or some other type of hose?

Hang in there!

[eric1ono]

Hey, just doing a follow up check on this. Are you now satisfied with the performance of your setup? No issues at any levels of the tank being filled, or under any throttle situations that you've seen?

Thanks for checking this out.

Eric

[rvaughnp]

Give me until next week. I have had to replace both brake master and booster and have yet to install them. I drove her three weeks ago and still all is good. The hose seems to be holding as the regular fuel line only lasted about three days being submerged.
I will post back this weekend on this.

[eric1ono]

Thanks. I understand about having to work on other parts...sometimes it seems like it never ends! Please post when you get a chance. Good luck.

Eric

[rvaughnp]

Ok, a reply on the drivability so far. Runs great. The hose is holding up as it was manufactured to do. Even though she had been sitting all this time... the pressure drop stopped at 10#'s. She took about 2 full seconds to fire up after sitting for about 4 weeks.

[rvaughnp]

A few days after Thanksgiving... I have taken her out on many occassions and everything "fuel wise" is working as it should.

Just wanted to add an update.

[eric1ono]

Great news! Good job and thanks for the update.

Take care,

Eric

[rvaughnp]

March 2nd, 2012.
Still working as it should. The check valves are working to a degree. It will loose about 2-3 #'s over night; but doesn't seem to affect starting at all.
Thoguht i would update again. Enjoy your weekend.

[CW6er]

March 2nd, 2012.
Still working as it should. The check valves are working to a degree. It will loose about 2-3 #'s over night; but doesn't seem to affect starting at all.
I thought would update again. Enjoy your weekend.

That's good, they only have to hold pressure until the engine cools down. The pressure after shut down is only needed to prevent vapor lock in the gas lines on those really hot days when the temp soars under the hood.

[eric1ono]

Man, I was just getting ready to revive this thread. I have finally buttoned up my single pump conversion as well, but I am having a strange running issue. I ended up diverging somewhat from your layout. I'll list out the how and why.

I had a Walbro 190Lph pump available and after looking through various places, and recalculating multiple times, the flow required for a 300hp car (mine's not that much, but I used this as a round number and to give some safety factor) I believe that the 190Lph pump should still be adequate for the job. Having said this, if I were buying a new pump today, I'd probably err on the side of caution and go with the 255Lph pump as you have. They look to be the same size with the same connector so I can upgrade later if needed.

My other diversion was in how I routed the fuel. I tried to set it up like your is, but I had a few issues. First, my tank is slightly different in that instead of 5-6 screws used to hold the in-tank fuel pump assembly in place my assembly simply slots in through the hole with multiple tabs on it, and you use a screwdriver and hammer to tap it clockwise 1/16th of a turn or less to lock it into place. The reason I mention this is I'm not sure if the opening in mine is slightly smaller in diameter or not because I could not physically fit the pump assembly through the opening in the tank. Another issue I had was I don't know if the diameter of the larger metal tube is different between the 2 types of tanks, but I could not get the 3/8" hose over the metal tube. It is made for 12mm (1/2") hose. I didn't feel comfortable trying to use a band clamp to squeeze 12mm hose down to 5/16" on the pump.

With these 2 issues I moved on to plan B, I mounted the pump on the 8mm (5/16") metal line which was originally the return pipe by cutting it short to give me the proper length when installed in the tank. That way I could use a short piece of 5/16" hose and everything fit as intended. I then set the large diameter metal line, originally the supply pipe, as the return line by using the short rubber adapeter piece that was used between the original aux pump and the larger diameter line and on the other end I used the section of 8mm pipe which I had cut off earlier. This gave me a smaller overall package and was just small enough to slip through the tank opening. Here's a few pics to help it all make sense:

http://i183.photobucket.com/albums/x264/ericono/IMG_0207.jpg
http://i183.photobucket.com/albums/x264/ericono/IMG_0208.jpg
http://i183.photobucket.com/albums/x264/ericono/IMG_0211.jpg

From that point I routed the 5/16" hose to a check valve. I couldn't find the BMW part so I got a low pressure check valve from McMaster Carr rated for gasoline. From the check valve to the fuel filter and then continued on to the supply hard line which runs from the back to the front of the car and on to the fuel rail.

I ran the 12mm hose to an adaptor down to 5/16" hose and connected that to the return hard line which runs from the front to the back of the car and connects to the fuel pressure regulator.

Other than this work I also: dropped the fuel tank, cleaned it out and coated it with POR 15 for fuel tanks. I replaced all rubber fuel hoses. I removed the injectors, including cold start, and had them ultrasonically cleaned. I installed a new fuel filer and a new pressure regulator (3 bar). I haven't cut the original main pump wires as I wanted to leave myself a back up plan if I had to go back to a 2 pump system.

Oh, and I installed a T with a schrader valve and hooked up a pressure gauge between the fuel rail and the cold start injector.

When I got everything buttoned up (the car had been sitting for ~2 months, unfortunately), I pulled the fuel pump relay and jumped the 2 wires to cause the fuel pump to run so that I could fill up the system without running the engine. It very quickly registered 44psi on the gauge. 3 bar is 43.5psi so I thought things were looking good.

I went to start the car and it took a number of trys, but she finally fired up. Unfortunately she sounded like a diesel, and I had to keep my foot on the accelerator or else she would not idle. Over 1000rpm the engine sounded smoother, not like a diesel at least, but she would rev pretty slowly. I revved as high as 3500prm. Seemed like she would do more, but I didn't want to push it. If I shut her down and tried again, she'd fire right back up, but the same thing: wouldn't idle on her own and revved slowly. The fuel pressure never wavered from the 44psi.

I didn't work on any other part of the car except the entire fuel system. Fuel pressure looks like it is what it is supposed to be. Any ideas based on what I have described? I really miss driving my car.

[86GT635]

Is it holding pressure after you turn the car off? Kind of sounds like it could be a vacuum leak. New o-rings on the injectors?

[rvaughnp]

- Is the pressure staying up while running and while being rev'd? It may drop like 2-3#'s (can't remmeber exactly what that drop limit is.).
- Did you use the gates 27097 hose (or similar)? If you used regular hose it could have split already.
You might want to go back to your pump and turn the "return" away from the pickup.

[eric1ono]

Thanks for the replies.

The pressure drops ~2psi after I shut the car off, but maintains that level for awhile. I just checked, and now ~3 hours later the pressure has dropped to 24psi. When I start it back up it jumps back to the 44psi.

It is staying up while running and being rev'd. The pressure doesn't change from the 44psi.

It is Gates fuel injection hose I got from Napa. Supposed to be high pressure hose (I paid enough for it, it'd better be). Not sure the Gates number. Napa's # looks like H205. I see C-U-06-002 on the hose itself and 4219D SAE30R9 180psi.

Good point. You can't see in the pics above, but I did bend the return pipe away from the pump filter. (I used your method of the screw driver in the tube to bend.)

And the injectors were completely rebuilt, new o rings, caps, etc. If I installed the injectors incorrectly, would that cause a vacuum leak but not a fuel leak, and would my pressure still read correct?

If my pressure is reading as it should, does this sound like a fuel issue or something else?

A few more questions: since my pressure is reading properly, does that mean I am getting the correct fuel flow amount?

As stated above, I primed the fuel system by running the pump before trying to start the car. Did I need to do something else to prime the injectors?

Is there any way to tell if all my injectors are firing besides taking the rail, with injectors, off and turning the engine over while pointing the injectors into cups or something?

Thanks,

Eric

[rvaughnp]

Pull the pump and check the hose. If it isn't the "submersible" type hose it will rip.
Your fuel pump may be pumping enough to keep the regulator at 44 psi but not enough volume to maintain the injectors to flow properly.
If you didn't use the Gates 27097 hose (or similar) that might be your issue.
I found out that regular high preesure hose wouldn't work with the hose only sitting in the fuel for about 3 hours.

[eric1ono]

OK, have had some time to try and diagnose a few things. The fuel hose in the in tank pump assembly is fine. No holes, tears, etc. I fired the car up long enough to let the headers warm up a bit and then checked. I'm only running on 3 cylinders. 2, 4 and 5 are not firing. I jumpered the main relay to see if that would change anything, but it did not. I don't mean to derail this thread so I'll start a new one and only post back to this one with comments about my single pump setup once the car is running properly. I just wanted to make sure someone reading this didn't think it was a fuel issue.

Thanks,

Eric