Hi, Seems like glow plugs are are not working. Harder than usual to start. WTS lamp comes on for about 8-10 seconds like normal.But lots of cranking to start. If I plug in block heater it starts right up instantly ,so not air intrusion. checked glow plugs are all good.
Could it be the relay? Or what else to check? What would let the wts light still work and not let the plugs work?
Thanks--Norm

 

yes the relay could be bad internally.
have you checked for voltage at the output of the relay to the glow plugs?

 

No haven't checked that. How exactly do I check it?
Thanks

 

get a volt meter, and connect positive to relay output, negative to ground. have someone turn key to on position and read voltage.

 

Great ! Thanks. If the relay is shot how would the wts light still light up for the normal amount of time? On my '86 the light would'nt go on when the relay cratered.
Thanks again

 

different systems. the late 87 and newer trucks used a solid state controller.
the controller turns the WTS light on.
on th e86 and older units, when the controller fails it sends constant power to the glow plug relay which in turn burns the glow plugs out.
on the 87 and newer units, when the controller or relay fails it will not send power to the glow plugs.

 

Well checked out the whole glow plug system, all checked out good.
I recently had an R & D IP and injectors & turbo installed more fuel & power . Works like a whole different truck. Very pleased with new power and performance.
It has been very cold here lately 15-20 degrees . Hard start now using glow plugs. Using block heater starts right up instantly. Have started it w/ glow at -10 before new stuff. Could it be the timing ? It's now set at 7.5
Thanks -- Norm

 

Could be a timing thing. Also, does the cold advance/high idle work?

I believe the GP system works on resistance, so if the connectors are bad/corroded it can cause issues with cycle time. I replaced all mine.

Also, with it being really cold, how fast does it turn over. The really cold weather has a noticeable effect on my batteries and cranking speed if everything isn't in top shape.

 

Thanks for your thoughts. Turns over real nice. Good voltage to each glow plug. I'm thinking the new pump and injectors are dumping in enough extra fuel to hinder it a bit?

 

try bumping the timing advanced by the width of a dime and see what happens. if it helps, bump it a dime width again. 7.5 is a bit retarded and that will give you hard start.

 

My truck has been a pain to start in the cold mornings also. About how long are you running your block heater for before starting it up? I was thinking of loading up a small generator to run the heater if i'm parked away from a place to plug in.

 

Plugging it in is something new for me lately. I've been plugging it in when I go to bed, way longer than necessary . I'm going to get a timer and set it for a couple hrs & see if that's long enough.

 

2 hours is usually good enough, three is better down ot around 10 degrees.
when you say "small generator", how small? you will need a 2,000 watt genset, the block heater is a 1,000 watt unit.

 

The generator is one of those Honda jobbers I think it is a 2,000 watt unit.
Good call though I didn't know the block heater was 1,000 watts!

 

Welp I'm sitting at the storage lot right now warning up the engine block for an hour and a half hoping to get it started!