Hi All,

I own a 2002 mazda familia sport20 4wd, with the 2.0L fe-ze engine.

This problem has been on going for the last 6 months, and i am failing to diagnose it.

When cold it runs fine, but once it is up to running temperature, it appears down on power, and when the revs reach 2800rpm, it looses power untill 5000rpm, and has a random hesitation/surging at any point on the rev range.

I have changed plugs, filters, cleaned the MAF, checked for vacuum leaks, checked fuel lines.

I took it for diagnostics, and it showed a fuel starvation issue, and even though the filter was only 500km old, we replaced it anyway, and this cleared the code. however the problem still existed.

The tank is clean inside.

There is also a very small rev fluctuation at idle.

Any ideas as to where to go from here?

Decent fuel (and maybe something like cataclean) and give it a good ragging. Fuel pump would be next one on the list after that.

If I remember correctly, I had a fuel pump seize up in my BJ, I removed it and freed it off. Might be worthwhile having a look, it could be sticking a bit.
I'd also have a good look around all the vacuum pipes in the inlet manifold area.

hmm.. i think that you have to see the pressure at the fuel rail.Does it fall down when you press the pedal..
It has to go up by 0.5 bar or so..