yester year part one

[Brad Clayton]

Remembering the good ol' days, or least as old as they get for me. The 7.3L was a brand new power plant and of great improvement over it's predecessor. The fuel water separator actually worked, and the glow plugs were controlled electronically instead of mechanically.

 

The manual transmission models were a dream to diagnose, they had no PCM! A truck would come in running rough and you grabbed a 5/8 wrench out of your toolbox cracking injector lines loose to get to the root of the problem. A manual compression test actually revealed problems with the engine. These engines were not trouble free by any means but they were reliable, although underpowered compared to todays standards.

 

Common problems in the hot states consisted of broken exhaust valves where they met the seats in the heads. Lifters would break, the push rods would go right through them. If a fuel knock occurred and was allowed to persist, a rod could "shorten" up on ya and if #8 did this then the piston skirt would strike the crankshaft counterweight and shatter. In the early years of the 7.3, hard starts could be tough to diag. You had to keep your wits about you do to a design flaw in the precombustion chamber. It would allow for carbon build up around the glow plug and absorb the heat. The easiest diag was to plug truck in for a while, if it started ok then the glow plug system was at fault. If all the glow plugs were ok and heating up correctly the truck was getting an updated set of heads. Speaking of heads, it seems the gaskets are always gonna be an issue, after all they have a pretty tough environment. These were bad about splitting around the water inlets at the end of the heads and would allow coolant to leak externally.

 

Timing the engines was unique at the time, the cam and crank had a mark while the cam and injector pump had a "y" mark to align correctly. If the tools for dynamic engine timing were not available they could be set with a pulse generator box clamped to the #1 injector line and a timing light with an advance option built in, 8 degrees(positive)+/-2. The fuel system was nice and simple. If the cam driven lift pump were to get weak then parking the truck nose down was a must to get the truck started. The injection pump had alot going on inside of it, but it worked or it didn't and you replaced the whole thing anyway. The biggest drawback was air in the fuel. This could cause problems that would make you pull your hair out to the equivalent of todays electrical/pid data. Keeping some fresh diesel around when doing a fuel filter could keep a starter out of the rebuilders hands for years.

 

I had these thing clocked and then all of a sudden the whole world changed and the Powerstroke was on my doorstep. There was absolutely no hype like todays new models that are waiting to arrive and training is needed for and so on. I had no idea that it was out or what it was until one came in on the hook shortly after it's debut. But this is for another post