91 stang 5.0

Hey guys im new to this forum. I have a 1991 hatchback with a small built 5.0. When i go to crank it the fuel pump dont click on til i get into the spring of the ignition and wont stay running. If i hold the key all the way forward and jump the started and continue to hold the key igt will run. Any suggestions?

mattdel

Ignition switch on the column is bad. Not the key cylinder, but the switch that it attaches to. Take the column shrouds off, you'll find it.

91 stang 5.0

I have replaced it 4 times now. Also replaced the fuel pump, relay, and checked the cut off switch.

mattdel

Well then maybe the key cylinder is bad. Clearly its a column issue, not anything else.

91 stang 5.0

Replaced that too. Its not getting power to the fuel wire on the ignition switch until the key is all the way forward.

mattdel

Is this a problem that developed while you owned it, or did you buy it like this? I ask because it sounds like maybe someone switched a wire in the harness for the switch to a spot it shouldn't be in, in some lame attempt to hotwire it or whatever... Im gonna go look at some diagrams and post again with what to look for.

mattdel

Check the red/light green wire shown here. Well, check them all actually.

91 stang 5.0

They are all in the right place. The red/green wire has power one u turn the key but the fuel pump doesnt click on until u get into the spring of the ignition. This happened after i got it. It just shut off one day

mattdel

Well the FP relay is triggered by the ECM, which is powered by that EEC Power Relay you see at the end of the red/green wire. I have no answer as to why it won't trigger until the key is all the way forward. Like I said prior, that tends to mean that the switch itself is bad.

91 stang 5.0

we fixed it. new dual plane intake n carb. thanks for the help.