My car has a 5.0, gt40 heads, mild cam, aftermarket intake & throttle body, 24 lb injectors, 180 t-stat. The car is running hot the gauge is hitting 250 degrees. I've been playing with fuel pressure and its around 42 psi now. I'm not sure what else to look for, the radiator is an aluminum one and has a hi flow electric fan. Any feed back will be greatly appreciated!
Regards!
Ed

 

check timing. check spark plug gap.


edit:

make sure your water pump isnt old as ****. you might be running lean too, make sure your fuel pump can supply the injectors.

 

there also could be an air bubble somewhere in your cooling system.
did you install the t-stat the right way?

 

always use a mr gasker hipo stat this has a bigger office and a small hole in the side to let water still trickle through.....If the water pump is good then timing or and an exhaust restiction. or a blown HG...are you using a stock gauge or a mechaincal one..

 

I have an autometer electronic gauge.

 

have you flushed the radiator? also are you sure the fan is even turning
on since it is electric.

 

Yes the fan is working and the fluids are new. I ran the codes and got 41 which is exhaust gas oxygen sensor voltage is always lean (low value) does not switch. What causes this?
Regards!

 

what year is your stang?

 

fuel pump might be on its way out and leaning the air/fuel. be careful.

 

A dying fuel pump can do that? What can I do to check the A/F mix if I don't have a A/F guage...anyway?