Wait to start light not working consistently...hard start when doesn't work

[Skenth]

Recently in the cold weather I have noticed hard starting and black smoke as a result of hard start...finally noticed that hard starts are related to the wait to start light not coming on. When the light does come on, the truck starts just fine...


Any suggestions on what might be causing intermittent issues....is something on its way to failing??

[whitehumh2]

Check your Glow Plug Controller but realize that you may have a defective temperature sensor that is not giving the controller an accurate reading causing it not to come on. So check those two things.
 
Check your glow plugs at the same time just to make sure they are working properly, but they will not cause the glow plug controller to not function.
 
Hope this helps.

[Roy]

also, the ecm controls the glow plug relay. I would test relay first.

[Skenth]

Thanks for the advise. The light comes on and off

I'll check the relay and temp sensor. Where would those be located?


I've been troubleshooting through hummer knowledge base (hummer network) and it seems like the problem is in the glow plug controller. I have checked the glow plugs and they are all good. I have installed a manual switch that controls the glow plugs and I can turn on the plugs for 5-10sec using a switch and the truck starts up fine. I do want the original "auto controller" to get fixed and use the manual switch in case it gets really cold and I need to manually cycle the glow plugs.

[Roy]

Should be located at the back right valve cover area

[Skenth]

Just got a new problem...dripping coolant..drips are constant and 15 seconds apart.


I think I'll set up a time with Phil to take a look at both issues and fix it properly. I love this truck and want to maintain it so I can enjoy it for many years.

[dwaxman1]

Sonny, did you get all your issues worked out?

[Skenth]

The coolant leak was quite extensive....one morning it was at least a litre of coolant fluid on e driveway. I didn't want to top up and drive to Caledon to see Phil and risk break down on the way and doing serious damage to the engine....so I found a local guy who will change the waterpump (quite a big job getting to it). He's bringing the pump and the serpentine belt (might aswell do it now) this weekend to finish the job. Hopefully I should b good by the end of this week.


The manual glow plug controller switch works fine. I flick it on for 7-10sec when the "wait light" doesn't come on automatically before I start the truck and it starts up right away...but I would like the original auto glow plug control mechanism to work (ill use the manual glow plug switch in extreme cold weather).


I'll take it to Phil once I can get the vehicle back on the road for routine maintenace and get the glow plug controller issue looked after.


Sonny

[dwaxman1]

good luck.. today's weather is not good to be changing a water pump outside...

[Roy]

When putting pump on, check for casing clearance on the passenger side. Found some that have to be fitted.
 
On the side note, I also offer flat bed towing!