also, someone above said about clamping the return line, to see if your pump is dieing, this is also used to see if injectors are fucking out(full of shit), and clamping the return line jacks up the fuel pressure thus pushing more fuel through the injector(conpinsating for blockedge), either uncloging it or if problem still occurs after unclamping return line, injectors are removed and sonic cleaned and flow tested, i often use this, and as my boss calls it "lebo injector service" clamp return line and take it for a thrash around the block