This has happened for about 3 years post rebuild and old ECU to fresh rebuilt and new ECU

This almost never happens when I'm driving during the winter, only during the summer after I beat on it or drive for 20-40 minutes although I've had it happen in less than 5 minutes on a 90° day where it shut my car off completely.

I drove around today for about 40 minutes continuously in 74° heat, fuel was halfway, at about the 20-minute mark car started losing power, after about the 30-minute mark I couldn't rev past 5K WOT (felt like a wall or hard cut), about the 40 minute mark I found out that I couldn't rev past 4K but only when WOT if I slowly rev it I can rev it past and go all the way up to 8k doesn't matter if it's a free rev or while under load/in gear.

What I've replaced so far

fuel Pump(3 times), pump sock(4 times), filter, new plugs, new wires (NGK), readjusted TPS (within spec), AFM is sitting oem position, replaced all vac line caps, idle air screw adjusted to Mazda spec, cleaned fuel pump grounds and wires and replaced my fuel pump Killswitch with higher amp switch (doesn't get hot)

Timing was set when we fired the engine up after the rebuild and hasn't changed or moved.

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And one last important thing is when all this is happening I can shut off the car and start it back 20 seconds later and nothing will happen for a solid 5-10 minutes I will have good power and no issues but then it will come back full force again.


Any ideas will help I have bashed my head against a wall trying to figure all this out and nothing has worked idk what it could be at this point other than a pressure regulator or some hose getting heat soaked or my fuel pump just keeps going bad idk.