6.5 Diesel Trouble Cold Starting
 

ANY SUGGESTIONS?

What are the symptoms? My 7.3 used to romp when really cold. Sometimes would barely turn over. Try cycling the glow plugs a few times before starting.

I'm with Sutphen30, it is probably the glo-plugs or the glo-plug relay. Just ohm meter check each plug when
it's unhooked from the loom.

Also make sure you got good battery power, those early models (6.2 & 6.5) need the starter turning max
r's.

I would check the relay first eventually the contact plate gets pitted up enough so it won't make good contact anymore. In mine you can see the volt gauge go down while it's drawing power so you might be able to tell while your in the truck. If not one morning when it's cold jump across the relay manually for a couple minutes and try to start it without waiting for the light to go out. If it fires right up the relay is probably bad if you still have the problem it is probably the plugs.

The quickie method that I used to use to check glow plugs: Disconnect the buss wire. Take a jumper wire and connect one end to the battery with alligator clip. Now touch the end of the jumper to each glow plug. If you get a spark, the plug is good. No spark, the plug is bad. I used to go through a set of glow plugs every season. Turn out the relay was defective and they were staying on. The light switch, although contained in the relay, was independent of it and worked normally.

What year model?
 

My diesel is a 1999 and mine went back to the dealership from where I purchased the truck 6 months earlier and they replaced the glow plugs for me. No Charge.
They are under warranty until 100,000 miles.
I also remember getting a paper from GM that extended the engine warranty to 120,000 due to some injector pump problems.

If you have good glow plugs then it may be time to replace the batteries. If the engine doesn't turn over fast enough it doesn't build enough heat of compression and so becomes hard to start.
When it is cranking is it blowing white smoke???
If it is then it is probably glow plugs.

thanks for the tips.i installed the remote start.it has a 10 second delay,and tries three times to start.i have it set on a longer crank time.when its cold it takes 4 or 5 tries to start.when plugged heater in it fired right up.if i use the key it will start but i have to crank it longer.also i do get smoke out the tail pipe.

If you are getting a lot of smoke then you probably have a few bad igniters.
If you try to change the igniters and they don't want to come out dont pry them out just leave them loose ( one at a time ) ( put a can over the loose one and turn the engine over ) the igniter will blow out. The can is important because the igniter will be like a bullit.

I had a 30 sec. delay I my remote start.

plug it in, plug it in.
 

Plug it in at night.

10 second delay is really short when it cold out The first thing i would do is set it to a minimum of 30 seconds. I know on the powerstrokes you can check the resistance in the glow plugs through the harness (the harness disconnects right at the valve covers) I'm not sure how the gm's are set up but that's a lot easier than pulling them. I did it once and replaced them all only to find out it was a bad relay, a really expensive relay after that.

I allways just use a test light to check glow plugs.disconnect lead,clip on pos.touch tip of glow plug with test light,if it lights you have a good plug.Glad you got it figured.:cool:

yea..plug it in over night.....

thanks for the info guys.did some checking my batt volts are 12.3. at hte glow plg i'm getting 11.3.is that enough?
also i have one bad plug but can't seem to get to the #8 to check it.so i may have 2 bad plugs.called the dealerand there is a $100 on the warrenty.they only replace the bad parts.if the relay is good it doesn't pay for 2 bad plugs.once again thanks for the info.

My remote start has a trigger wire that hooks up to the glow plug light. It waits until the light goes out and then turns over. I had to use the long crank time.

In the winter it usually blows white smoke and coughs for the first 15 seconds or so, then it starts running better. I never plug it in at night. I rarely use the truck in the winter.

Steve