Fse boost valve on a 106 xsi help

[killerscum01]

Hi all,

Just aquired a 106 xsi, and when cold it missfires, and also when trying to do a constant speed it hesitates badly, someone has fitted an FSE boost valve to the car and also a stupid volume type switch to the air temp sensor.

Firstly do you think this could be causing the problems??

Secondly has anyone got a photo of under the bonnet or can explain to me in graphic detail where the fuel pipes are supposed to be connected??

Thanks in advance: Bart

[Stu R]

Bin the volume style switch first, if i'm reading you right it sounds like he's done the "power resistor" type mod but using a variable resistor to fool the ecu by changing the signal.
as for the FSE valve, personally I'd ditch that too.

[AntMat]

Why would you bin the FSE rising rate fuel pressure regulator? If set correctly it can help tractability and in some cases top end performance.

[Rob_the_Sparky]

AntMat said:

Why would you bin the FSE rising rate fuel pressure regulator? If set correctly it can help tractability and in some cases top end performance.

It richens the fuel mixture by increasing the rail pressure (and IIRC is adjustable). If running closed loop then the ECU will back off the fuel to compensate (e.g. on the cruise). When in open loop it may help a little but this depends on the original set-up. If it was a bit lean to start with it can help power, if rich then it will not (and can even drop the power output). Depends on the car and the set-up but not something I'd fit on a 205 GTi, not seen feedback on a 106.

Spend cash on proven (e.g. not marketing bull) performance mods. E.g.on a 205 (may apply to 106) forget bling air filters, noisy exhausts, electric "turbos" etc and get some headwork done to the engine or fit a turbo/super charger.

[killerscum01]

Agreed with all, and i want to ditch the fuel regulator and put it back to standard but i'm not sure how it is plumbed, There are 2 pipe fittings on the fuel rail one is directly above the standard regulator and the other is slightly higher and to the right but which is feed and which is return?? and also the one that is directly above the regulator has just been left open to atmosphere, as far as i can tell all the vacuum stuff underneath it is still connected, So why isn't fuel pi**ing out of that pipe.

[Rob_the_Sparky]

Don't know the 106 but the high pressure fuel comes from the fuel tank to the rail. The regulator then returns any spare fuel to the tank. E.g. high pressure comes from rail to regulator, low pressure from regulator to tank.

Regulators normally have 3 pipes, high pressure fuel, loew pressure fuel and manifold pressure (vacuum).

Hope that helps

Rob

[killerscum01]

Also does anyone know if this car has an OBD socket and where it is, it is a 'K' reg with a bosch motronic ecu