PCM voltage question

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Sep 27, 2014 | 12:13 PM

JeffMoore

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Joined: May 2014

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PCM voltage question

I have an 89 F-150 with a 302 and AOD transmission. When I lug it down in 3rd or 4th it bucks until I roll on the throttle and it kicks down into 2nd or I pull it manually down into 2nd. It is worse on a hot day and not so much when cool.

The truck always starts quickly when cold but needs to crank a little more when warm or hot.

The idle is around 800 RPM and the exhaust smells rich to me.

I've looked for vacuum leaks and found none. All the ignition components have been replaced.

All sensors check out electrically and the PCM sends no codes other than 11.

So now I have checked the reference voltages to the sensors and brings me to my question.

Do I have a problem with the PCM or not?

With the KOEO the Ref voltage at the MAP, TPS, and EGR pos. sensors is 5.02 Vdc While the voltage at the IAT and ECT is 4.63Vdc. The Haynes manual says it should be Approx 5.0 volts.

It is just that 4.63Vdc bothers me. Is 4.63 approximate enough or do I have a problem?

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