Right after i start the car it seems to have quite a bit of low end... i can drive around town fine keeping it under 3k (untill its warm), even after its warm it seems to drive fine.

Basicaly after i have been on the highway for about 10 minutes the car seems to lack power. This continues once i am off the highway and i basicaly have to downshift to go up hills a lot more than i normaly used to.

The car is a 91 n/a with a CAI and True Duals, radiator has been flushed recently, the oil is new, plugs are new, wires are less than a year old.

This weekend im planning on replacing the vac hoses and regrounding... but i dont know if that will have any effect on this.

I'm not getting any CEL's so if anyone has any idea what would cause my car to do this lemmi know. Also are there any sensors (particularly temperature related) that would cause the engine to go into limp home mode without throwing a CEL?

 

Fuel pump inlet filter...

 

I have been meaning to clean that... would that only cause a problem after its been running for a while though?

 

Classic symptoms are what you described- mine got to the point where it would start, and I could accelerate up through 5th gear, then she'd slowly lose power till I couldn't go faster than 20 mph or so.

Might as well change your main filter also, if you haven't already...

 

main filter is a year old, so i doubt thats the problem....

would you recomend buying a new in tank filter or cleaning the old one...

if i should buy a new one, where would you recomend getting it (dealer?)

 

They don't seem to take to cleaning very well, but guys have done it...

Got a Mazda dealer close by?

 

yeah, ive got a dealer close by, i guess ill go there tomorow and order one

also, what would be the reason for a clogged filter causing a slow decrease in performance, just the restriction causing the fuel pressure to drop slowly or something else?

 

Have you pulled the pump/filter assy out of the tank recently?

Have you added any injector cleaner recently?

Have you started premixing recently?

 

ive never pulled the assembly out

i dont think ive added any injector cleaner recently

i premix periodicly with a casterol outboard oil (tcw3), but ive been doing it on and off for a while

although a few weeks ago it did feel like it was about to cut out when i made a hard left... so that seems to point to that filter as well