Ford 7.3L Powerstroke Difficult Cold Start


Problem: Several things could be causing difficult cold start problems for your 7.3 Powerstroke:

Cause: Stiction in injectors

Solution: Treat with Stiction Eliminator to clean out injectors

Cause: Poor fuel quality

Solution: Treat fuel with Diesel Extreme

Cause: Glow-plug problem

Solution: Check glow-plugs


Your Powerstroke engine uses a HEUI style injection system to pressurize the fuel entering the combustion chamber. It does this with a complex, hydraulically actuated injector. What hydraulic oil do they use? The very same that lubricates your engine. When this oil gets too hot and burns, it leaves a varnish-like material in the injectors, making them stick when cold (what we call “stiction”). Treating the engine with the Stiction Eliminator and running it for one full oil change interval should eliminate the problem.
If you have used Stiction Eliminator, Diesel Extreme, and Diesel Winter Anti-Gel additive as recommended above, and you are still having trouble with cold starts, it’s likely that the glow plugs are not operating correctly.

1. Listen to the glow plug relay. You will hear an audible “click” when the key is turned on.

2. Check all the wiring leading to the glow plugs for breaks or cracks in the insulation. A single chaffed wire can throw out a whole bank of plugs.

3. If the wiring looks good, measure the resistance across the glow plug to see if it within specifications; an “OL” reading on your Digital Multi-Meter means there is no continuity in the circuit, and the glow plug is bad.

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