Fuel pressure regulator issue

[DRGTV6]

Hello everyone.

I am in need of assistance with troubleshooting a fuel issue.

I first came across a problem when I started noticing that my fuel pump was not working properly and died. I replaced it with a new fuel pump and fuel filter and all was working well. Then after a while, I started noticing fuel pouring out of the exhaust when I cranked the engine and the bike would not start. I took everything apart down to the injectors. Both injectors seemed to be working well and after getting advice from all of you, I came to realize that the problem was likely a faulty fuel pressure regulator. The bike had the original Weber fuel pressure regulator. I tried finding an original part and I was VERY lucky to find one still available on a shelf in a dealership in TX. I ordered the part and installed it, put everything back together and fired her up. She was running great, fired up quickly, and there was no gas coming from the exhaust. I allowed her to idle for a while in the driveway and I started closely inspecting the engine. I noticed then a steady drip of gas coming from the fuel pressure regulator line that feeds fuel into the regulator (the line directly on top). The bike was running fine and I could not figure out why it was dripping. The clamp was on well and not loose. Then all of a sudden, the end of the hose that inserts into the fuel pressure regulator burst and split and fuel came gushing out of the line. I immediately stopped the engine. I took everything apart again and replaced the hose and reassembled again. I started the bike and again there is still dripping of fuel from the exact hose that brings fuel to the pressure regulator. I am unclear why fuel is coming from here?? The clamp is on well and not loose. It seems to me there may be some back pressure perhaps building up from the return line back to the tank?? I can't imagine the issue is a faulty pressure regulator again, although if it was sitting on a shelf for many years in a dealership, maybe it is faulty??
I'm thinking about purchasing another regulator (perhaps the one that fits the BMW K series) and give that a try?? Could there be excessive buildup of fuel pressure in the lines??

This is driving me nuts!!!

Any help is greatly appreciated.

Thanks.

ANTHONY

[st2sam]

Lets start with something simple first.

A blocked line? Is the tank venting OK? Is the new fuel pump the correct one?
Hang in there Tony, the boys from down under and across the pond are pretty sharp, they'll chime in soon...

Sam...

[907pasonut]

not having much luck there Anthony, I'm just wondering if you have the connections at the tank the right way...delivery to the injectors, from injectors to top of regulator, from rear of reg back to tank, if the flow is reversed pressure will build up.

[st2sam]

Anthony, keep us posted when you get this sorted.
It'll be interesting to find out what the problem was.

Notice I said, "when", because you will sooner or later!

[Bonza]

i have a 92 851 as well as a 907 same pump and regulator the nimrod i bought it from had the fuel lines all cocked up it still ran ok but it eventually blew the pump and regulator go to a ducati and get a tech sheet on the fuel line routing good luck

[ducinthebay]

make sure all of your fuel lines are rated for fuel injection, and the clamps are for fuel injection. Don't use the old style side screw and slotted band. This mangles tubing, and creates leaks. http://www.jpcycles.com/product/7200763 ... QgodLSoAjw

Use the type that have two flanges, a screw and nut. Much more even pressure and less chance to pinch and bunch up the hose.
http://www.jbtoolsales.com/k-tool-05181 ... 8-10-pack/

Ran around the block on my 98 ST2 with fuel lines leaking, and this certainly cured it.

Cheers, Phil

[DRGTV6]

Thanks to everyone for their input and recommendations.

The fuel pump is the correct match, purchased from Euromotoelectrics.com
It is the Bosch replacement for the original weber pump.

The lines appear to be free of any clogging and the tank vents seem clear.
I will check the lines and the tank vents again to be sure.

The hoses are lines up in the right direction based on the movement of fuel in the workshop diagrams.

I was not aware of the differences in the rubber hose clamps.
The clamp that is holding the hose which brings fuel to the regulator (hose to top of regulator) was actually a slotted/braided clamp. I will change this over to the 2 flange clamp and see what happens.

The fuel line coming from the injectors to the top of the regulator may have been changed by the previous owner and the one on there is a Goodyear hose 1/4 inch (6.5mm).
Is this the correct size fuel hose??

I will keep you all posted.

ANTHONY

[907pasonut]

the FI hoses are 7mm