Hello everyone I'm new to your group. Have a 85 Blazer with the 6.2 great truck except for the first start in the morning. Have to cycle the starter and glow plugs 2x to get it to start. Not sure if this is kinda the way this engine starts when cold.

Have replaced pick up pump and starter and new battery's and starter, glow plugs. My vac pump is bad but should'nt add to this problem. Thanks everyone have a good one..

 

I would check for power at each glow plug wire when the wait to start light/glow plug light is on,there are fusible links between each side glow plug wires as well as to each glow plug that might have burnt out.

Also glow relays fail over time.

The cold start switch on the rear of the passenger side head controls cold start advance that as well may be a factor?
A temp sensor also decides if the glow plugs activate.

What color smoke do you see when starting?
What brand/# glow plugs did you put in for replacements?

 

I have Bosch glow plugs, but haven't checked the voltage at each plug in. Have by-passed the glow plug timer with a ford solinoid. Will check out the cold start, and temp sensor. On start up both banks have black smoke . Let you know how things go on my days off...thanks again.