s12045

hi newbie here just wondering if anyone could help or have any idea's.
I have recently got a mk6 1998 escort si 1.8 16v basically since ive had it all it seems to do is stutter pullback sound like its hitting rev limiter between 3/4k ive tryed everything new sensors including maf still no joy, i have also changed fuel filter which when i take it off to check it and then put it back on the car runs ok for a while then the problem come back again!! Im getting really fustrated as i cannot pinpoint whats causing it, im now thinking maybe it could be fuel pump but surely it would just pack up rather than playing up before it dies.Also i have noticed a valve on the injection rail which when i press it fuel just trickles out when car is running or not. dont know if its meant to do that, so if anyone has any idea's please let me know.
cheers

tabetha

There should not be any fuel coming out under any circumstances, whatever you press.
What exactly is the "thing" that you press, it sounds like it could be the fuel pressure regulator, which if duff can cause all sorts of problems with fluctuating fuel pressure as the air fuel ratio will be constantly changing, but if pressing causes a leak it needs fixing like yesterday anyway, unless you are reffering to a little valve the same as you have on a car tyre tp pump up, as these are often the type used to hook up a pressure gauge, it has a "pin" type bit in the centre which if pressed causes the fuel under great pressure to come out.
If you haven't done so look at plugs, for tracking, a fave with Bosch plugs on these engines, for some odd reason, then if not already change the fuel filter for a new one, as no visual check will tell you anything.
tabetha