only starts with fuel in throttle body
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Junior Member
Joined: Jan 2006
Posts: 3
Likes: 0
only starts with fuel in throttle body
i just got a 93 f150 5.0 it has been sitting for awhile, to get it to start you have to put fuel in the throttle body then it runs fine but if you turn it off you have to put more fuel in to get it to start back up. what could cause this? also it idles fine till it warms up then goes real high there is a unit of some sort in the left corner of engine compartment with an electric conector and a throttle cable going to it that was unpluged but doesnt change anything if it is plugged in? any help would be greatly appreciated thanks
Senior Member
Joined: Jul 2004
Posts: 6,200
Likes: 39
From: Easton, Pa.
If the plug goes on a device bolted to the throttle body, you need that connected.
If it does not do anything then the device is not working (IAC).
Some one may have adjusted 'up' the throttle stop to keep the engine running. This is not proper.
Clean the throttle body, the IAC and check for the stop screw being set up, then go from there to see what you have.
Test fuel pressure at the fuel rail with a gauge. It should be about 39 psi +/-.
Fuel fuel filter etc.
If it does not do anything then the device is not working (IAC).
Some one may have adjusted 'up' the throttle stop to keep the engine running. This is not proper.
Clean the throttle body, the IAC and check for the stop screw being set up, then go from there to see what you have.
Test fuel pressure at the fuel rail with a gauge. It should be about 39 psi +/-.
Fuel fuel filter etc.
Member
Joined: Jan 2006
Posts: 50
Likes: 0
From: IL
sounds like a fuel supply problem... test your fuel pressure mechanically.
sounds like you either have a weak fuel pump or bad regulator. take the vacuum line off the regulator and see if gas comes out the vacuum hose... if it does, replace it. if you have weak fuel pressure... replace the pump.
sounds like you either have a weak fuel pump or bad regulator. take the vacuum line off the regulator and see if gas comes out the vacuum hose... if it does, replace it. if you have weak fuel pressure... replace the pump.
Senior Member
Joined: Jan 2003
Posts: 150
Likes: 1
I have seen this exact symptom caused by a faulty throttle postion sensor.
The sensor will fail in the wide open throttle position, causing the computer to go into flooded engine mode. In this mode it cuts the fuel off while you are cranking.
The sensor will fail in the wide open throttle position, causing the computer to go into flooded engine mode. In this mode it cuts the fuel off while you are cranking.
