Lean codes, hard starting cold

[69 Sportroof]

'95 LX 4.6 -This is driving me nuts. Started with a check engine light, pulled the codes and got 17X; left bank lean/right bank lean. Changed the fuel filter,ran slightly better but cold start symptoms remain.Pinging (lean) under hard throttle. Where do I go from here? I wouldn't expect both 02 sensors to go bad at the same time. Are there any common intake leaks these motors are known for? Help me out guys, I'm a 351C Holly double-pumper kinda guy. This is my wifes car and man oh man, you know the deal!

[BKB]

The EEC has tried to correct the lean condition by increasing the injector pulse times. It is out of range and still cant correct the problem. I would look into the fuel pump, make sure the fuel pressure is good. If the vacuum leak was that large i would think it would be loud as hell and not idle at all. Whats the mileage???

[69 Sportroof]

120K, all highway. Yeah, I hear you you'd think I could hear it sucking somewhere if it was that bad. I'll check the fuel pressure at the schrader next, what is normal psi at idle?

[BKB]

around 39psi with vacuum hose off regulator. With that mileage i would either use some kind of tester like a Ford Star or a Meter to check the 02s. They should be switching very fast once up to temp. 02s make there own voltage so put you'r meter on DC volt 0-5v range and unplug the 02 proble the wires untill you find the 2 that have voltage. The other 2 wires are for the heater. like i said they should jump from around .9v to .4v or something like that its been awhile since i did that.

[69 Sportroof]

After I check the fuel pressure, I'll do that. Had a thought, if it turns out that they both don't seem to respond meterwise, what would happen if I provided a "fake" 02 signal from a separate voltage source. My background is in electronics, so would rigging an 02 reference voltage for what the computer wants to see make it richen the mixture?

[BKB]

Originally Posted by 69 Sportroof

After I check the fuel pressure, I'll do that. Had a thought, if it turns out that they both don't seem to respond meterwise, what would happen if I provided a "fake" 02 signal from a separate voltage source. My background is in electronics, so would rigging an 02 reference voltage for what the computer wants to see make it richen the mixture?

Haha its not that easy. I am also an electronics engineer. Either buy new 02s or get a tuner and run in OL like i do. My car a 94 stang and has no 02s.

[69 Sportroof]

On a related note, I just received the Ford manual for the 95 t-bird/cougar. Everything BUT fuel injection related other than a description of sensors as they relate to the transmission operation. What is the name of the Ford manual that goes into the specifics of the emission/fuel injection? Is it the Powertrain Control/Emissions Diagnosis manual?