jumpinthemiddle

Currently half way through building an St170 throttle body project.
Have completed the hard stuff but am struggeling with some of the wiring if anyone can shed some light.
I have had the car running on omex and started the mapping process.

taking one step forward and two steps back as usaul i have decided to do away with the St170 fuel rail due to the fact of the regulator being welded on.
I have now installed an older model fuel rail from a blacktop with an adjustable regulator to up the pressure.

My problem being that the St170 rail that i have discarded had a pressure sensor on it and the blacktop rail doesnt. Now the car wont start.
The plug that went with the sensor is now looking at me saying 'you shouldnt have taken me out'
I have a feeling that with this sensor removed the ECU will not be recieving a signal of pressure/temp which in turn will mess things up.

In short... does anyone know how to get around not using a fuel pressure sensor on the St170? Im sure this conversion with the combination of St170 running blacktop fuel rail has been done in the past.

Any info on St170 with ITB's or any help in general would be greatly appreciated

cjwood555

The problem stems from the ST using a returnless fuel system. Have you gone over to a return system now or blocked off the line?

Either you need to go for a return system, in which case you will need to run a new line in and replace the pump with a normal 2.0L one and remove the pump controller (see ETIS for location - from memory it's against the inner sill on the drivers side, under the carpet).

OR you need to fit the pressure sensor so that the pump knows what to do

HTH
Chris

jumpinthemiddle

I have swiched over to a return now so i could run the new reg.
I will look into switching the st170 fuel pump for a 2.0 zetec pump and see if this solves the problem.

RCCossie

Ive also got a project ST170 on the go. will keep an eye on this

jumpinthemiddle

If i switch the St170 fuel pump for a 2.0 zetec pump will i need to change the sender unit in the tank?
Also if i remove the pump controller for the St170 fuel pump will the 2.0 zetec pump run ok?
These may sound like silly questions but want to get it right the first time round
Thanks

cjwood555

Hi mate,

The sender is attached to the pump so no worries there.

Where did you run the return to? The 2.0L pump has send and return connections on top of the pump. If you've gone straight into the tank then you'll have to blank the return connection, though that may affect the effectiveness of the swirl pot. Best approach would be to use the pump's return connection and blank off any new one you may have made.

Yep the 2.0L pump runs from a straight 12V, so you need to bypass the controller. May be best to leave it in place (to avoid any errors coming up) and link the 12V to the controller to the pump +ve wire. Will dig out ETIS to check the connections for you

Chris

jumpinthemiddle

I ran the return back to the tank with the other fuel lines under the car. I am currently in progress witu replacing the st170 pump with the 2.0 zetec pump and disconnecting the 12v feed to the controller to feed straight into the new pump.

d8vyr

hi there, knows it`s an old thred but just wanted to check, did the blacktop fuel rail fit straight on to the st170 inlet, cheers davy