runnermedic

im thinking that if the fuel is dripping back to the tank with the engine off it may be a faulty fuel pressure regulator and this is causing the pump to keep on building pressure and not turning off after priming it keeps priming endlessly.
the hesitation is when i press the pedal from idle and then in heavy load also pinging in heavy load, if i push the pedal to the floor it will hesitate then slowly build up speed.
im going to pinch the fuel return line and see what happens,maybe this is why rpms are low while idling

plugs are new
fuel filter new
no additives to fuel
maf cleaned
all vsv's tested and all good
tps good
iac good
no coolant leaks
no vac leaks
coils are good
spark plug wires are good

the older spark plugs were light tan in the tips and the ceramic, the tip a little black and the first ring a light tan.
normal or lean condition??????

runnermedic

update here
pinched the fuel return line today and the pump stills running while engine off
tested cor again and its ok still hearing the fuel going back to the tank

hesitation resolved found 2 problems that miss before
the internal boots of the spark plugs where cracked at the end with evident marks of arc
so i replaced them/i verified the maf again (cleaned with rubbing alcohol before) and found that still have some grime in the wires so i picked up a can of maf sensor cleaner and done the hesitation is gone,now the engine runs like new.
also found something if i replace a light bulb or anything that is electrical the cel will come on but specially with the light bulbs, don't know if this is normal but everything is ok now.

STILL GUESSING THE FUEL PUMP ISSUE
to do: replace the evil fuel sending unit mine is stuck at 1/4 near empty, low fuel stills warns.

runnermedic

what is the point with the fuel pressure regulator line connected to the airbox (per diagram)
there is no measurable vac there,i was looking at my others cars and the fpr line goes directly to the intake and if i disconnect the line there will be a vac leak
so whats the point?

take a look at this picture from another member who did the isr mod,this one makes sense for me
tell me if im wrong
http://i827.photobucket.com/albums/z...3/100_2600.jpg