Recipe - Ford 7.3L Power Stroke Diesel (T444E)
Reliability build
Reliability tier: aggregated - verify before ordering, see /disclosure/
Cold-start system service (modes Glow plug / glow plug relay failure / Under-valve-cover harness (UVCH) failure): HEUI needs glow assist below ~40F, and the chain fails link by link - plugs, the single heavy relay, and the under-valve-cover harness connectors. Renew the whole chain before winter, not one plug at a time.
Parts
- 7.3L Power Stroke Glow Plug (OEM) - glow plugs - renew as a set, not singles (qty 8)
- 7.3L Power Stroke Glow Plug Relay / Control Unit (OEM) - the single heavy relay - dead relay strands the truck on the first cold snap (qty 1)
- 7.3L Power Stroke Under-Valve-Cover Harness 1999-2003 (OEM) - under-valve-cover harness, 99-03 Super Duty (one connector per bank) (qty 1)
- 7.3L Power Stroke Internal Injector Harness 1994-1997 (aftermarket) - under-valve-cover harness, OBS era (two connectors per bank) (qty 1)
Install order
- test the relay first: 12V at the plugs for the glow cycle or the relay is the answer
- resistance-test the plugs through the valve-cover connectors - bad legs trace to the UVCH
- renew the plug set and the era-correct harness (OBS two connectors per bank vs SD one)
Expected outcome
Reliable starts below freezing; no more single-cylinder smoke on cold mornings.
Do not
- do not skip the UVCH when one bank tests dead - a new plug set behind a chafed harness fixes nothing
Parts budget
About $55-$160 in parts. It depends on what the diagnosis finds; each option below is what you buy together. Prices marked "at Dave's" are Dave's Auto Center's, the same as in his store; the others are approximate prices from OEM and maker catalogs, rounded (a manufacturer's list price can run higher). Parts only, no labor.
DIY or shop: DIY: valve covers off, hand tools; a weekend morning.