OTTP return fuel system
 

This will be a write up on how to install the Return style fuel system by OTTP, as well as how to modify the fuel canister for a larger fuel pump

First off, I am not responsible for any wrong information given here on or any damage you cause to your car.

Start by removing any built up pressure in the fuel system, I suggest pulling the fuel pump relay and cranking the car.

Jack up the car and safely support it. You will need to remove the exhaust in order to drop the tank.

Step 1- unplug the electrical connections for the fuel pump, level sensor, and evap

https://cimg8.ibsrv.net/gimg/www.cob...7c99585508.jpg


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Step 2- remove the 2 fill lines from the tank to the fuel neck

https://cimg2.ibsrv.net/gimg/www.cob...8578d1867f.jpg


https://cimg3.ibsrv.net/gimg/www.cob...e78f32a85c.jpg

Step 3- remove the 2 fuel lines to the fuel filter and the one leaving and remove filter itself, also the clips that hold the wires to the body

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step 4- double check that all lines and electrical is disconnected and the tank is ready to drop. If ready remove the 2 straps and take the tank out.

step 5- spin the locking ring off the tank, take note to use a brass punch or simular tool so you dont create any sparks

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step 6- remove the canister and the outer part by popping the 3 tabs

https://cimg1.ibsrv.net/gimg/www.cob...2d4de6da50.jpg


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Time to modify the canister for a larger pump

you need to cut out this portion depending on how big your pump is

https://cimg5.ibsrv.net/gimg/www.cob...9f3d9f9f06.jpg

It should look something like this

https://cimg8.ibsrv.net/gimg/www.cob...7a926b217c.jpg

now you need to cut down the top plastic that goes on the fuel pump exit to a length depending on the pump you chose

Before:
https://cimg6.ibsrv.net/gimg/www.cob...ed463204dd.jpg

After
https://cimg8.ibsrv.net/gimg/www.cob...e310cb4860.jpg

Now to wire up the new pump. If you have the option to get new clips I suggest that route as shown

https://cimg7.ibsrv.net/gimg/www.cob...d92a18ab9a.jpg
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https://cimg1.ibsrv.net/gimg/www.cob...ed002fce87.jpg

The final step for the fuel tank is to remove the stock regulator, which is just a piece of spring steel and ball


https://cimg3.ibsrv.net/gimg/www.cob...9e09c561b4.jpg
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put the cover back on or some people like to run a line to the bottom of the canister, its up to you.

Everything is done and you can reassemble and install the tank again.

Next mount the new fuel filter

https://cimg7.ibsrv.net/gimg/www.cob...e1d09052b3.jpg

hook up all the electrical and fuel lines except the line on the tank for the return, that will be connected to the return line we will mount later

Now for the fuel rail, take the fuel line off that feeds the rail

https://cimg0.ibsrv.net/gimg/www.cob...ff8c709978.jpg

unplug the fuel injectors, unbolt and remove the rail.


https://cimg1.ibsrv.net/gimg/www.cob...d865f8ca83.jpg

Now is a good time to put bigger injectors on if you want for your build

https://cimg3.ibsrv.net/gimg/www.cob...346b85b16e.jpg

Now assemble the fuel regulator

https://cimg6.ibsrv.net/gimg/www.cob...4c3548e81f.jpg

Remove the end cap on the rail and mount the regulator

Reinstall the fuel rail and route the return line somewhere safe and away from the exhaust.

Connect the vacuum line to the intake manifold

Fasten the fuel line to the body of the car with the supplied hangers and self taping screws, taking extra care to keep it away from the exhaust on the rear twist beam.

install the supplied fitting to the line and attach to line going into fuel tank

Final steps

make sure you have all fittings tight and electrical plugs connected securely.
Reconnect battery and fuel relay
turn on car to prime the system and look for leaks, do this a few times and set fuel pressure

You may want to get a tune before going into boost or even driving any distance especially if you have different injectors


That should be it!!!

Here are more pictures and a link to my photobucket seeing I met the max amount for the original post


Link to Photobucket
http://s897.photobucket.com/user/rob...9/library/fuel

This is the end cap that needs to be removed on the fuel rail
https://cimg8.ibsrv.net/gimg/www.cob...7b194bd732.jpg

and you might have to cut down the rubber depending on the fuel pump you chose

https://cimg0.ibsrv.net/gimg/www.cob...63f1610b61.jpg

Great write up ! About time someone made one.

Would you happen to know where i can buy a new rubber o-ring for the end of the fuel rail ? Where the fitting attaches to the rail.

Im pretty sure I only used the stock seal that was in the end cap. Ottp sends a o-ring with the kit but it caused mine to leak so I took it out and just used the OEM one and no leaks in the 2yrs it's been on.

I've been meaning to do this write up for like 2yrs, so I was thinking hard on what I all did to make sure I didn't forget anything here

wow just the how to i needed at perfect time about to pop on my aem 325 e85 pump

Nice write up.

What if you don't have the stock assembly for the fuel pump and it doesn't have the stock fuel pressure regulator in it instead of it having a box and electrically done it's a manual pressure regulator do you remove that whole thing (wish I had a picture of it) if so then how does the car have fuel pressure from the fuel lab ? Or

Great how to thread!!!

Im not sure what you mean. The stock fuel pressure regulator is just a peice of spring steel, its 100% mechanical. The metal will bend at a certain PSI. On the stock fuel filter it has 1 line going in and 2 lines going out. 1 line goes to the fuel rail and the other goes back to the tank to the stock fuel pressure spring, the aftermarket fuel filter is a single in and a single out fuel comes from the pump and then goes out to the fuel rail. the new fuel lab pressure regulator goes on the end of the rail to control the pressure and the return line off of that regulator goes back to the return line on the fuel tank

Say you bought a fuel pump from Napa advance where ever and it doesn't have the same style you still have to remove it correct because that's where the return line will be feeding back into the tank from?

http://www.carid.com/ic/carter/fuel-pumps/p76252m_6.jpg Mine has this style pressure regulator would I just take that whole unit out then or?

I have the aem e85 high flow fuel pump wired up for return style in a stock canister. Is the only other thing I need is the adapter for fuel rail to make it return style and a fuel pressure regulator with lines? Thanks!

you will have to bypass that regulator unless that one is set lower than what you set it at the rail but that should be avoided

you will need a fuel filter with just a single in and single out with the same type and size quick fittings that are on the fuel lines,

you need to drop the tank and remove the stock regulator

The pressure regulator and fitting for the rail and a return line

and fitting to go from the return line to the stock connection on the fuel tank lines

they are all generic parts you can buy if you know what type and size, which i dont know off hand

Awesome thank you! I bought the pump off of a member on here who had previously purchased the Ottp kit. Wasn't 100% sure what all else I needed to make everything work

So then I pull that whole unit out then if I set the one on the rail higher what does it need to be set to cause it reads 60 psi but it's all the way threaded out what should it be set to or does it depend on your mods if so Tvs 1900 e85 Walbro 450 and 80s with supporting mods

There are plenty of threads on this. Easiest thing to do would be talk to your tuner.

fuel pressure is all up to your tune, anytime you change pressure you need to adjust the table or you could run rich or lean especially under boost

Wow.... The AEM e85 320 pump is a Royal pita. definitely have to cut down the rubber piece sliding into the fuel intake hose, also have to cut the plastic part of the intake hose all the way down to the flat. After that you need to remove the inner canister filter and dremel some plastic down just so it can fit inside the canister. Running just the stock external canister filter.

What i did and a couple of buddies have done is just remove the grey piece altogether and just hose clamp the line onto the outlet of the pump itself.

ya, the pictures I had were from the DW300 I originally had, but that only lasted 2 tanks of E85 so i switched to the AEM pump and had to cut down even more and i dont think i did enough because now I dont read under a 1/2 tank so i think my canister is bowed..

I have to see if the AEM will be enough for my new turbo setup, shooting for 550+, might have to do a dual pump or a surge tank setup next

Yeah I thought about that but the fuel return hose gets in the way. Unless I can just cut it short... I am running an external regulator, but do we need that extra ground from the pump that connects to that return hose??

No you dont. I took the entire stock regulator out and just shoved the hose down into the canister.