Gman36

Hello i got a question. I have a 92 f150 4wd 5 speed... So the other day i went outside in the morning started it up and it just kept idling up and down up and down check engine light was on. I shut it off and tried to start it again wouldnt start just cranked... I got home from work that evening and it started right up no cel The next morning samething kept idling up and down... Well the next day i plugged in my odb1 to test it. I turned on the key and noticed my fuel pump kept running wouldnt pressure up.i tried both tanks I tried to test it and my scanner wouldnt work. I unhooked the neg cable for 30 seconds and reinstalled it. I turned the key back on and within 2 sec fuel pressured up and it started and ran good... Tested it and it passed... Well next day same thing fuel wont pressure up and wont start.but if i unhook neg cable and reinstall it fuel will pressure up and it will start. I have put new canister purge valve. New egr. New batt cables. 2 new fuel pumps 5 months ago.Kinda weird do ya think it could be my fuel pump relay. Or computer. Any help would be much appreciated..also when it was idling up and down it was shaking and i noticed a tiny bit of black smoke comming out of tail pipe

Steve83

Stop replacing parts. Remove the EEC (two 10 or 11mm nuts, and an 8 or 10mm bolt in the middle of the connector), and look inside, as this caption describes:


(phone app link)

Follow the link in the caption for more info.

Gman36

Oh ok sweet thanks ill do that