GTX motor cutting back at 4.5k

[Maz1.8T]

Glad to hear you got her going.

A surge tank is a device that you put inside your gas tank that is taller than the "cup" your fuel pump currently sits in. It prevents fuel from sloshing out of it while taking hard turns and during accel/braking and therefore prevents the pump from losing the fuel around it. I heard guys on fordlaser.com have built them themselves or have had them done professionally

Actually you can put a surge tank almost anywhere you want. It is used in EFI conversions where the stock low pressure fuel pump feed the surge tank. From there the high pressure pump feed the engine. The fuel pressure regulator dumps in the surge tank too and there is a return from the surge tank to the gas tank. Here's a link on how to build one and the theory behind it:

http://toyotaperformance.com/surge_tank.htm

[jacobrussell]

The boost cut is built into the ECU, not the AFM! Once the AFM reads a certain value (on the 0-5 V potentiometer which it is), the ECU will assume it has reached too high a boost and cut out. That voltage value is based on the stock GTX vaf which just like any other vaf can be tuned by tightening or loosening the spring..

so i guess im one of the very few poeple who has read the shop manaul


over boost is a calculation done by the ecu it uses the vaf AND the tps

i sujest you replace the VAF with a rx7 B series dont dick with the spring just put it on set plugs to a gap of .030 fill her up with premiem NOT av gas or Trick fuel these are high in lead and will kill your o2 sensor..

you also didnt go enuff into depth on why you tune the vaf or how to

to tune it correctly at idle with all accessories off you test the o2 sensor for .5 volts tune for .5 volts if its off.. but i sujest you do not do this until you have put in a brand new o2 sensor.

if you wanna get good milage replace it with a 3 wire

wire the sesor out put up like normal then ground one of the heater wires and put the other on a ignition source

oh and RTFM guys