Knock sensor & Hard cold starts

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Sep 8, 2010 | 01:48 PM

alsiroc

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Joined: Jul 2009

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Knock sensor & Hard cold starts

I remember seeing a thread on here or another forum that if the knock sensor is connected but not installed in the block, it could make the truck hard to start when cold. It had to do with the engine adjusting the timing to the point where it would try to produce a knock to verify that the sensor is working. Does this sound right? I tried to search for the post but I couldn't find it again.

The reason I ask is my truck is hard to start when it's cold. At first I thought it was fuel pressure (problem with check valves) I rigged the fuel pump test lead on the computer connector to a momentary switch in the cab so I can start the pumps and bring the pressure up before I try to start it. This helped a bit, more so when the engine is hot.

I'm not sure why the knock sensor is just hanging there. I'm going to be pulling the upper intake soon and will see if I can get it installed again. Just looking for some input, maybe some ideas why the PO might have disconnected it. I don't hear any ping when I drive it like it is. Thanks and sorry for the rambling post.

89 F150 Custom Longbed, 302, 4spd