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Dec 10, 2004 | 08:16 PM

Rubbersoul

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tbs

89 E150 4.9L efi
I was told that I should have .9 Volts key on engine off.
I have 4.98 Volts
they said to loosen screws to adjust.....it did nothing.

I have 4.98 Volts idiling.........at my wits end....HELP!!!!

Dec 11, 2004 | 02:45 AM

Ford_Six

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Joined: Oct 2002

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From: The Big, Oregon

It sounds like you are measuring the sensor hot voltage, which is the power supply for the throttle position sensor. With the connector plugged in, you have to backprobe the right wire with a straightened out paper clip.

Dec 12, 2004 | 01:10 PM

Rubbersoul

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thx jared I'll try that today

Dec 12, 2004 | 03:14 PM

Rubbersoul

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Just tried it Jared, got 1.23 Volts, key on Engine off, loosened bolts,would move a little up down,(the voltage) but never below 1, the reason I dont get how loosening the bolts is it's attached to the throttle body.

Dec 12, 2004 | 03:30 PM

EPNCSU2006

Lead Driver

Joined: Nov 2002

Posts: 9,557

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From: Concord, NC

The two screws holding the TPS down is what needs to be loosened. Then the TPS may be set up so that it can't be moved anyway. With the TPS bolted down, probe the harness and watch the voltage as you gradually open the throttle to wide open. The voltage should steadily increase to somewhere around 4.8 volts at full throttle. If the voltage jumps any, replace the TPS with a new one. If the TPS still reads ok on the voltages, and it won't rotate enough to get it down below 1V, you can try drilling out the screw holes in the TPS so you can rotate it a little more to get the voltage at the correct level for closed throttle.

Dec 12, 2004 | 03:37 PM

LxMan1

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Joined: Dec 2001

Posts: 22,436

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From: Louisville,Ky.

You may also have to back off the throttle stop screw. If it has been adjusted up any, the throttle may not be returning to the closed position which is why it won't drop below 1V.