Just installed a polished UIM. Had to take all the solenoids off my old uim and also the TB to transfer onto polished unit. That went well without any snags.

Turned the car on and adjusted the idle. Everything was good to go.


Took her out for a drive and noticed my fuel pressure gauge was marking about 28psi. The pressure always marked at or about 36psi. While driving, it hesitate as I try to accelerate,...noticed the fuel pressure goes down as the car hesitates. At WOT the car doesn't really do anything but stumble,... the fuel pressure drops to about 20-22psi. It never did this before!!

Could it be that I pinched a fuel line while putting on the UIM?? Maybe the Fuel Filter?? Are there any other adjustments I can do on the TB??

Any advise/help would be greatly appreciated.

Thanks. -Jimmy

 

Sounds like your FPR/fuel pressure regulator is not hooked up properly.

But it should not have been affected by removing the UIM. It has a hose that goes from the LIM to the FPR solenoid to the FPR.

The FPR solenoid is not really needed as it is another piece of useless junk Mazda put on the car. But you need at lease the hose from the LIM to the FPR to regulated FP as boost goes up.

From you questions it is obvious that you do not know your car! The fuel filter is near the gas tank. The fuel lines under the UIM are too low and thich to have been
pinched.

Take it all off and check it all out.

If the MAP sensor hose was not connected, you engine would idle very rich and the engine would barely run, but the FP should still be good.

I do hope you have the Mazda Service manually. It is your bible to understanding you car!

 

Thanks. I know where the fuel filter is placed. I just thought my acute problem might be associated with a filter gone bad/clogged. Thanks.