90 351 fuel problem
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90 351 fuel problem
i just bought a 90 f150 351 auto. problem is the truck wont build fuel pressure to start. pump is new and so is rear tank. front tank was removed by prev. owner and pluged off. no leakes around plugs. usually i have to use either to start but if i do it idles rough and check engine light comes on untill it warms up then it runs fine. tried pulling codes but got some wierd numbers that didnt make any sense. if the trucks been ran for a little bit and it doesnt sit for too long it starts back up. im at a loss for what it is.
Fleet Owner
Joined: Aug 2005
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From: Easton,Ks
When the ECT sensor is bad a lot of the time it will not throw a code.
The computer just looks for something being outside of a high and low voltage range.
As long as it is in this ballpark range even if it is wrong the computer is happy and will run with that voltage.
You can try testing the ETC sensor over a heat range and see if the readings are right.
Put it in a pan of water with a thermometer and hook a ohm meter to the sensor and see if the resistance is right for that temperature as the water gets warmer.
You can go to this link for the values:
http://fordfuelinjection.com/?p=28
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The computer just looks for something being outside of a high and low voltage range.
As long as it is in this ballpark range even if it is wrong the computer is happy and will run with that voltage.
You can try testing the ETC sensor over a heat range and see if the readings are right.
Put it in a pan of water with a thermometer and hook a ohm meter to the sensor and see if the resistance is right for that temperature as the water gets warmer.
You can go to this link for the values:
http://fordfuelinjection.com/?p=28
/
