[69idi]

I have a 85 f250 6.9 diesel, has 235000 miles. Within the last month I have replaced the glow plugs, relay, and selinoid because it was getting harder to start and i wasn't hearing the buzzing noise when the glow plugs were cycling. It has a manual glow plug switch that was on it when i bought it. I tested to make sure power was getting to the glow plugs, and each glow plug was getting 10V. It starts fine when its warm and it idles fine but won't start without being plugged in if temp is below 30. After doing all those repairs I still don't hear the buzzing noise when the glow plugs are cycling, what makes that buzzing noise? Is it the injection pump? Any help would be greatly appreciated.

 

[nine9six]

To be honest, you'll probably get much more help over at OilBurners.

TONS of info over there, and great members with loads of IDI knowledge.

 

[dipperc30]

I have an old 6.9 1987. Cold starting is made easier with 2 very strong batteries and the use of starting fluid. The glow plugs just dont have enough power to warm up the block sufficiently. The high milage lowers the compression somewhat making starting harder. Starting fluid shouldn't hurt the engine. Anyway, diesels depend on cylinder compression to build up enough heat to ignite the fuel. Harder with an old engine so it needs help from the starting fluid. PS never use the starting fluid and the glow plugs together. Something bad might happen.