Running WAY too rich

[banditmwp]

Ok, i checked the TPS voltage because my 91 was running rich. It read 4.9 volts with the engine off. The 5 volt reference was there too. So I replaced the TPS. Same reading. Different one. Same reading. I really don't think that I had four bad sensors. So what could cause the TPS to read wide open all the time??

All the induction components are stock...intake, MAF, TB. The injectors are stock, as well as the fuel pressure regulator.

I checked the grounds in the engine compartment, and at the ECM. The car is an AOD to T-5 swap, if that helps.

 

[Sevan]

are you using a special tool to measure the voltage? I want to check my voltage but have no idea how.

 

[jrichker]

You have a missing ground for the TPS? The black/white wire is the ground and should always be used to take readings for the TPS. If the black/white wire does not connect to ground at the computer, the TPS voltage will always be high.

With the engine off, if the resistance between the black/white wire and battery ground is more than 1.0 ohms, you have a problem

A good DVM (Digital Voltmeter) is a must have item to check the TPS voltage.

See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host)

http://www.veryuseful.com/mustang/tech/engine/images/88-91eecPinout.gif

 

[banditmwp]

the ground is in place at the computer