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Hard cold start diagnosing?

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Old 01-08-2017, 08:28 PM
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Hard cold start diagnosing?

Hey Ya'll. I'm getting ready to start looking into this when I'm off later this week, and want to start getting it planned out.

When I bought the truck (in the summer) it would fire off perfectly, so I know it normally starts fine, it's just the cold that's doing it.

But, it's not that cold (considering where in NC I am, it typically doesn't get much below 20, if that). It seems that it begins being cranky about starting somewhere in the 35-40° range. If it's in the 30s, I'm having to plug it in to avoid having to crank it overly long, and ask it nicely to start, lol.
​​​​​

I know I need to start by checking the GP relay, but if that's not it, where should I go from there? I've read that the injectors can cause rough cold starting, but I'm not sure how to go about checking that.


Thanks y'all
 
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Old 01-08-2017, 08:49 PM
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Start with the GPR. There will be no need to go further that there if that fixes it. What I do when I suspect mine has gone out, I take an old screwdriver and put it across the 2 big terminals and hold it there for about 30 seconds, then I go and hit the key and see if it starts. If it does, then I know what the problem is. Also, you can do a voltage teat with the key on across the terminals. If you get 12 volts with key on and the GPR is suppose to be activated, it's bad.
 
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Old 01-09-2017, 01:51 AM
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Not necessarily John...i had 12v at trigger wire, 12v at pos post, but nothing at gpr post. My pcm isn't grounding out the other little lug to transfer the power to gpr side
 
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Old 01-09-2017, 06:04 AM
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Since it runs fine in the warmer weather, there are three possibilities: Compression, heat, and fuel.

Heat comes by way of the glow plugs when it's cold outside. Fuel can be interfered with on worn injectors, but synthetic oil in the winter can give you a stay of execution here. Compression is a straightforward test if you have the right tools - pretty easy to do if you are already in there to change glowplugs or do other under-VC maintenance.
 
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Old 01-09-2017, 08:23 AM
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Well, I'm off starting Wednesday, and depending on the weather I'm gonna try to do some boost leak testing. While I'm under the hood, I'll go ahead and check the GP relay. If it's good, I guess I'll report back and go from there.

I can make it through the winter just fine by plugging it into a timer over night, it'd just be nice if I didn't have too. And I know there must be some issue, as it oughta be starting better around 35° than it is.
 
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Old 01-09-2017, 12:12 PM
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Old 01-10-2017, 09:44 AM
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I know you said starts fine in the summer. It so did mine. Not saying this is the issue but worth consideration and the read IMHO.

https://www.ford-trucks.com/forums/1...read-this.html
 
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Old 01-11-2017, 09:34 AM
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Agree with FireFighter.... if that's your original starter on a 400xxx mile truck, go get a new starter. I was amazed at the difference.
 
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Old 01-11-2017, 09:50 AM
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Alright, my plan of attack this afternoon is to test the GPR, and pull of the starter motor. I'll take it to a shop tomorrow for testing and probable rebuild.

I'm stepping up the importance of figuring this out now. I'd been getting by with plugging it in for the mornings, but I've been told I'm going to night shift next week, and I don't if there's a place I can really plug it in at the plant.
 
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Old 01-11-2017, 03:50 PM
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Originally Posted by Oldanvilyoungsmith
Alright, my plan of attack this afternoon is to test the GPR, and pull of the starter motor. I'll take it to a shop tomorrow for testing and probable rebuild.

I'm stepping up the importance of figuring this out now. I'd been getting by with plugging it in for the mornings, but I've been told I'm going to night shift next week, and I don't if there's a place I can really plug it in at the plant.
Tugly/Rich touched on acouple of things I think we tend to forget about. As
long as your GP, GPR, Batteries and Starter are all in good working order. Switch to a full Synthetic oil and change your Fuel Filters. My son who lives/College in Ames Iowa forgot about this too. Last winter he didn't change his oil over. This winter he didn't change his fuel filters. So he's paid for it 2 winters in a row now. Not sure what they're teaching him over there . I guess he enjoys riding his bicycle to class in sub zero weather LOL.... You can take a boy out of S.Ca, but you can't the S.Ca out of the boy...
 
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Old 01-11-2017, 05:28 PM
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Alrightie!

Glow plug Relay - Good putting out right at 12 volts on the GP side.

annnnddd..... Glow plugs... 6 out of 8 tested with no continuity. (3 on each side) and the 2 that showed continuity had .9 ohms on one, and 1.9 ohms on the other.

So, I'm thinking I need to do some glow plug replacing.


Should I even bother pulling the starter and having it tested tomorrow, or would ya'll say that's pretty much the issue? (I'll probably still check the starter sometime, but if that's not my cold start issue, then it's not as important)
 
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Old 01-11-2017, 08:08 PM
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Problem with these trucks are a lot of small things start adding up to a big thing. I had brand new glowpligs, injector o rings, Newer battery's, newer battery cables and still had a hard start issue. Again not saying it's the starter. But knowing that I have been threw two sets of batteries and changed the glowplugs twice in the last few years and finding out it was the starter. I still say it's worth the time to pull it and get it tested. Also make sure all your battery terminals and grounds connections are clean. That includes the ones that go to the block.
 
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Old 01-12-2017, 12:48 PM
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Welp, I got $90 worth of glow plugs, and even stopped at HF to get a universal for my ratchet, as I'd read it's hard to get that back bolt off (agreed).


So now here I am withy first VC off, then I realized that like a dummy, I didn't check whether the GPS were metric or standard. I don't have any deep well metric sockets... Dang.

(Keep in mind whilst laughing at me I'm used to working on my 86 Ford, a whole lot less metric on that thing, lol)

So whilst I go back to HF and get some, here a couple pictures I'd like ya'll to take a gander at. First one is the impeller blade on the turbo. It's kinda rough, which isn't shocking on a 400k mile turbo and I'm planning on addressing low boost issues in upcoming truck adventures, but should the nick's on the corners really worry me? Or is not so bad considering the miles?






Next is just a pic with the VCs off, in some stuff I've seen, it sounds like the browner the back of the injector, the older it is. These are pretty brown, so I'm assuming they're pretty old (possibly original?) Is there any testing I can/oughta do to these whilst the VCs are off?



 
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Old 01-12-2017, 02:02 PM
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You could always fire it up with the covers are off after a sitting all night for a good cold soak. The injectors that don't spirt oil are the ones giving you a rough idle when it's cold. At least if you an idea as to what you are looking at.
 
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Old 01-12-2017, 03:54 PM
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Yup the Impeller is toast. In this condition it'll cause a low boost condition. Riffraff has a billet wheel for $179 & stock replacement for $66 iirc. I just installed the billet wheel on the wifes Ex and it works nicely. The GP's are a 10mm deep socket. It you find it hard to remove them after you've loosened them up, slip a piece of fuel line over the top, turn and pull them out. It's just very tight in there.
On Edit; I realize you've got a lot of miles on your injectors, but if it runs fine in the summer, I'd just try re-torqueing the injectors and see if that helps. Injectors are rebuilt $135/ $270 new give or take.
 


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