can anyone could give me some suggestions i have some problems with my mercury mystique 2000 its V6 2.5l The car was working good then on the road i discover that at high speed feel like lack of power i tried to accelerate but instead speed and revs go down ok then i replaced de fuel pump filters, clean the inyectors change the oil and the car was worste i turn on car and on like 3 mins works great but then starst shaking and if i accelerte it may turned off, i have used 2 kinds of fuel pump i dont know what to do its makin me crazy please from your experience i hope someone could help me!!!! 0.0

the sump in the fuel tank might have a blockage. the easiest way to test this would probably be to put a fuel pressure gauge on the Schrader valve on the fuel rail and see if revving it causes the pressure to bottom out. if that doesn''t happen, you may have to check the injectors themselves to see if they are working properly. is the check engine light on? if so, do you have a code? There could be numerous sensors that if they go bad could cause that. a bad oxygen sensor can also cause this on some engines. Might also need to check the plugs and wires or just give it a top end tune up (new wires, plugs, rotor, distributor cap). If it uses coil packs instead of a distributor, you may need to check the cam position sensor for proper function.

(personally, I''m leaning towards the bad oxygen sensor, but this is strictly a guess because I usually work on older vehicles - 10+ years old)Edited by: slymer

but i have changed the fuel pump 2 times still the same, and cleaned the inyectors, but yes the check engine light is turned on, mmm but it says the alternator was damaged and i changed too[img]smileys/smiley19.gif[/img][img]smileys/smiley19.gif[/img][img]smileys/smiley19.gif[/img]