Join Date: Dec 2008
Location: Tyler, TX
Thanked 407 Times in 347 Posts
The Power Stocke engines DO NOT typically need glow plug replacement, be SURE you test them before wasting your hard-earned $$$ on parts that still work as new.
The most common causes for hard starting relating the the GP system are: Bad (worn out) Glow Plug relay, and bad connections to the GPs at the "UVC" (Under Valve Cover) harness.
With the Wait To Start light ON, check the battery voltage at BOTH large terminals of the GPR (Glow Plug Relay), they MUST be the same measured to BATTERY GROUND, or at least within 1/2 volt of each other. Again, with the WTS light on.
If they are not the same voltage, then make sure the GPR is actually working. With the WTS light on, there should be battery voltage on one of the small terminals of the GPR, and ground on the other. If this is true, the GPR is bad. Replace and re-test.
'93 F-250 HD, 7.3L IDI, 5spd - FARM TRUCK
I Support: Trailer brakes an every axle over the towing vehicle's GVW; CDLs for RVers; Safety inspections for ALL vehicles and 6 axle trucks (97K GVW proposal).
Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote - Benjamin Franklin
I vote for LIBERTY!