5.0L (1979-1995) MustangTechnical discussions on 5.0 Liter Mustangs within. This does not include the 5.0 from the 2011 Mustang GT. That information is in the 2005-1011 section.
Sponsored by Weld Racing
Welcome to Mustang Forums!
Welcome to Mustang Forums.
You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, at no cost, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!
1990 5.0 7UP, been sitting over a year. Replaced fuel pump and fresh fuel, fires up when cold, runs 3-5 mins, starts stumbling and dies,fuel pump reland and WOT relays clicking, rapidly, NEW TFI, then found dead EEC relay...replaced. Same Problem. WON'T pull codes. Is the STO supposed to have batt voltage when key is off?? Goes off when turn on Key. Ran wiring harness, found no problems, have voltages at EEC per info I can find. Even opened up EEC looking for bad capacitors. Didn't look like any leakage, although board looks like overheated on section where you would add a piggyback. Have spark at plugs and 35psi when problem happens. Seems to be all electrical problem..........anyone have any ideas?? Been running on this for over a month!!!
This ad is not displayed to registered or logged-in members. Register your free account today and become a member on Mustang Forums!
That sounds Ilike the same symptoms my car had a couple years ago. It turned out to be a bad ECM. Bought a reman. from AutoZone for $99, ran perfect after that. Just for giggles, make sure your grounds are good and clean.
306 with all bolt ons, letter cam, ported E7's, T5 swap, full exhaust, 3:55's, 2" drop, and the worst paint you'll ever see or feel.
Dyno'd 300/316, 2745lbs-track scale
Best ET………12.4@108, 1.66 60ft on 8" ET Drags.
24 mpg (combined)
Orange Peel-- major problem was INDEED the eec. A bad eec relay going bad had fried the eec. Ran quite well considering it's been sitting so long, even with a new fuel pump and fresh fuel. At least now the MIL comes on, pulled a code 54 on it. Gotta' do a little more work.
This forum is owned and operated by Internet Brands, Inc., a Delaware
corporation. It is not authorized or endorsed by the Ford Motor Company and is not affiliated with the Ford
Motor Company or its related companies in any way. Ford® is a registered trademark of the Ford Motor