6.2L starts then dies
 

My 6.2L chevy diesel will start right-up when cold and then die after revving up to about 1500 rpm. This all happens within 1 or 2 seconds. I then have to then add a few seconds of glow plug (it has a manual glow plug switch) and crank it for 4 or 5 more seconds before it will finally start with a huge cloud of gray smoke. Once it runs a few seconds it will restart beautifully the rest of the day! Any thoughts!

I will sure appreciate any thoughts.

When was the last time those glow plugs were changed? They might be weak. Make sure the glow plug relay is working properly..........or just change it out to eliminate doubt.

Yeah I'd start with a new st of GP's grey and white smoke at start up is a good sign that they are on there way out use AC/DELCO glow plugs and with your truck you don't have to take the inner passenger side fender out like us with turbos have to do to change them also check all the wires to the glow plugs sometimes when on older glow plugs the ends where you plug the wire harness melt because the GP shorts out.

Thanks for the reply. The thing that bothers me is that it starts fine the first time with no smoke, but then dies after about a second. Its the second start which requires several seconds of cranking after which it starts and smokes. I had a r-manufactured engine put in last summer, so the glow plugs should be new.

P.S. On the first start of the day, how long do your glow plugs stay on when the outside temperature is in the low 40's?

Thanks again!

I would say my glow plugs stay on 30-45 seconds and then afterglow is 15-20 seconds and never assume anything when you yourself didn't do the work some shops cut corners and what may have been a good glow plug last year might not be good now or like I said in previous post the wires leading to the glow plugs might have burnt in two usually this is because the GP has shorted out corrosion at the tip will do this and in Northern climates salt from road spray will accelerate the process, the manual GP button leads me to believe that one or more things may be a issue in your truck A. Glow plug controller B. Temperature sensor . C ignition switch as for the 3 use only AC DELCO for the first two and as far as the ignition switch NAPA is ok any others you are wasting time and money.

And when it's colder glow plug times are longer and it will start first time at below zero without being plugged in I do plug it in though for maybe a hour to aid in warming it up quicker at the lower temps plus it's easier on the engine.

And if my engine takes more than a second or two to fire up I'd be really surprised and my engine is the original one from factory IP and injectors were replaced about 4 years ago along with new bushings for the turbo.

Thanks for the Ideas!

WOW, I've only been running my plugs 8 to 9 seconds. What is afterglow?

I inspected the wires and checked the resistance of the plugs, about 2.2 or 2.3 ohms. Does that sound about right? I think I'll replace them in a few days when I get a chance.

You are right, the glow plug controller died twice on me in the past, both times it turned-on while driving down the freeway and took all of the plugs with it. I cost several hundred bucks to replace, so the last time, about 20 years ago, I just went to the hardware store and bought a $3.79 push button to replace it. No problems since.

Also, several years ago the lift pump failed so I put on a small electric fuel pump since the lift pump was behind the turbo and would have required removing the exhaust system to get at it. That apparently didn't get re-wired with the new engine. I've rewired it in case the new lift pump is letting fuel leak down away from the injection pump (if that is possible). I'll drive it for a couple of days and post back.

Afterglow is when the truck first starts running glow plugs come on while running to help the combustion process along.