hey people, tried to search for any info couldnt find a thing. when my car has minimal petrol thats when it runs its best with no restrictions at all!!!!! after i fill up the car goes like a pig with not the same acceleration. bit of info on the car, its a orig turbo, i hav a sard fuel reg pumping a lil extra flow through the injectors, however i have had the fuel tank replced n now im assuming the intank fuel pump is an n/a is there difference?? this was replced 3 or so months back and this issue has become more and more noticeable over the past few weeks. it also sounds like its missing until i put my foot down. im assuming it has something to do with both the external and internal fuel pumps or spark plugs or the leads i am not sure. thanks in advance michael

when was the last time you changed your fuel filter?

have not changed the filter

I have the opposite problem. Over 1/4 tank of fuel - car runs fine. Below 1/4 tank, and can't bring it on boost or it starts running rough. Putt it around off boost and you can run the tank dry if you wanted to. I assumed it was the internal pick-up pump. Replaced it and the fuel filter to have the exact same still occur. Since I intend to upgrade the internal pump, external pump, injectors & fuel pressure regulator, i've just ensured I keep it above 1/4 tank for now.

InsaneVL i have same problem once she gets low it's coughing and farting. I would almost think bluey 87's problem is in his description. "i hav a sard fuel reg pumping a lil extra flow through the injectors" Prolly pumping out a bit of black smoke as well. Lower you run the tank the less fuel you pick up and it starts running well. Might have to adjust fuel reg.

the difference is insaaaaane!!! thanx 4 the input guys!!!!! ill take a look at the whole system!!!! or i mite jst put in $10 in at a time haha

should i raise the fuel pressure or lower it???

Quote: Originally Posted by bluey87 should i raise the fuel pressure or lower it??? if u want to lower the amount of fuel going through the injectors i would say u want to lower the pressure???

I had similar problems going back some time now and was the internal fuel pump, had a spare one in the shed from the vl formula(standard 3lt) and replaced it with that, since then no problems. Plus the mechanic was telling me that the VL(ie turbo or standard 3lt)internal fuel pump are the same. internal fuel pump = low pressure external fuel pump = high pressure

Quote: Originally Posted by bluey87 should i raise the fuel pressure or lower it??? set it at factory pressure with a pressure gauge. dont guess as lowering it to much will starve you of fuel.

thnx 4 the tips and advice guys much appreciated!!! michael