Hard cold start

[2stroke]

I get better and quicker responce on this forum:
My 97 7.3 PSD which always started good, maybe 2-3 glow plug cycles, has now refused to start when the temp is below 40. If we get a warmer day starts good as before or when driven, then parked and started a few hours later it still starts ok. I know someone will say plug it in, but thats not the point, unless the temp goes down to teens or less, that may be the plug in temp.
As a comparison my 89 idi will start no matter if the temp is in the teens--maybe takes a few more glowplug cycles but it starts.

Thanks to all the good knowledgeable people on this forum

 

[Defrocked]

I'm not very knowledgeable but sounds like its time to check your glow plugs or your control module for them.

 

[Wyreth]

Have you tested all your glowplugs to see if they're still alive? Is your glowplug controller switching the contactor on and off properly? Have you changed out the contactor? (don't know what is involved with that on a PSD tho)

 

[2stroke]

I would like to check the glow plugs as one or more could be bad. How-where do you check them. On idi just check each plug with ohm meter at the plug. But on this psd they are inside the valve cover. I think a connector on valve cover may be the check point but I don't know the pin Id.

As to the controller where is it located so I can give it a visual, but it may be OK as this truck starts Ok any temp above 40-45. I tried an experiment by short cycling the glow plug cycle when the temp is say 50 and it doesn't start. I must full cycle and like I said over 40-45 all is OK

 

[2stroke]

bump

 

[79jasper]

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Will look like the aih relay, but you won't have the aih, nor the gpcm.

I can't find my PDF on testing.

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[2stroke]

Not shure what this means. If the psd doesn't have this then what does it have

Will look like the aih relay, but you won't have the aih, nor the gpcm.

 

[79jasper]

It's real easy to find.
Just look on top of the engine.

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[Agnem]

Here are a couple of diagrams that will help you.

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[79jasper]

Mel, those didn't show up.

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[icanfixall]

I'm not certain this is factual but its something I was told some time back about psd glow plug systems. The current needed to the plugs is 110 volts and its clearly shown as I think orange wires. So if the valve covers are off look at the color of the wire to the plugs. That color wire will have 110 volts in it all the way back to the controller. Be careful. If this is not true please confirm this. Spreading wrong information is not something I want to do and usually try to verify anything I post. But this is needed info for the person "going in"..

 

[79jasper]

Incorrect.
The injectors get that voltage.

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[oregon96psd]

wow...glowplug relay is on the top left hand side of the engine when looking at it from the top. The valve covers have two plugs each in that year, the outter terminals are for the glow plugs. If it wont start at 40, you definately have problems, mine will start down to the lowest temp ive ever been in...-25