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Discussion Starter #1 (Edited)
On the 1996, 451,000 miles, it does not like to start on a cold start when below 70 degrees outside air temp. If it has any engine heat at all it starts up fine with a short cranking time.

While glow plugs may be a contributing factor, I don't think that's the only problem. Even with most glow plugs dead, it should start at 65 degrees.

The tach moves when cranking and new CPS made no difference. Cranking speed is normal. Had a friend watch while cranking this weekend at 70 degrees and there was no smoke until right after I let off the starter. Hit it again and it fired right up. Smoke was white. On colder days you can crank forever and it will not start. A shot of ether will make it fire right up. Yes, not recommended, but it works. Does blow a large cloud of white smoke on an ether start.

When I see the truck again Thursday I will open the fill hole on the HPOP reservoir and check the level prior to cranking. Assuming it was a low HPOP reservoir, would the ether shot be enough to suddenly fill the reservoir back up? If 60 seconds of cranking won't do it, who does a split second do it when the ether explodes?

Anything else I can check? Anyone in the North Texas area or Hill Country have a scan tool and spare time?

Once started, truck runs fine. I solved my cooling issue so now if I can solve this I'll be in pretty good shape to make 500k.
 

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My 94 (with 255k on it) was starting much the same way when cold out and that was with a good Batteries, starter, Stancor, good harnesses, and glowplugs (checked everything). The only thing I could chalk it up to was the injector armature clearances getting a bit low. Most of the armature plate clearances were around 0.0015". If I didn't end up with the 97, I would have been getting stage 1's for it. Cheers!
 

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Discussion Starter #3
I'm not familiar with injector armature clearances. What are they? How do they adjust? This truck had 8 new injectors at 395k. Can't rule them out, but suspect the problem is somewhere else.
 

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Have you tested the GPR? Sounds like it may be bad.
 

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Discussion Starter #5
Glow plug relay checks good.
 

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The armature clearances may not be your problem if you replaced injectors. To check the clearances you have to remove the solenoids on top of the injectors. Then measure the clearance between the square armature plate and the injector. It should be around 0.003". The injector's are getting tired if 0.002 or below. Cheers!
 

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Discussion Starter #7
I finally solved this problem. I replaced all the glowplugs, UVCHs, valve cover gaskets with Ford parts and fixed the damaged connectors. Still no change. So I said I'll try the relay even though it tested good. Sure enough that fixed it. So even if your GPR tests good, change it anyway if you have a similar problem.
 

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A simple test on the gpr is to jump the two large terminals, your literally bypassing it this way.
 

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Holy necropost Batman, you put up with that for over three years!!! That sure wouldn't fly up here, eh Jim?

Not surprising what you found; a GP relay can appear to "work", and technically feed voltage to the plugs, but just not enough to get them really heatineg. A simple "yes/no" test of the relay isn't good enough, as you found out. The proper test is to check the voltage DROP. Turn the key ON, then measure the voltage at the "always hot" big terminal, and then again at the other big terminal (the one going to the GPs). If the DIFFERENCE between the two is more than 0.3V (some say up to 0.5 is okay), the relay is faulty, even though it's making contact. I'll bet that if you did this test on your old relay, that's what you'd find.
 

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Discussion Starter #10
It's only a few months a year here when it's an issue and until I fixed it the 96 was not my daily driver. I had seen directions for testing the relay somewhere else on the site and it passed that test. I had also read that the relay could pass that test and still be bad. I was hesitant to replace it as I've replaced relays on two previously owned trucks in the past where it was not the problem.

I'm glad both of you replied so that information is in this post when someone searches on it 5 years from now. Plus I'll know exactly where to find it next time.
 

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Glad you got it fixed. I've had the same problem with the GPR - seemed to test ok but a replacement ultimately fixed the issue. The truck would typically start around 50 degrees without, with a good amount of cranking. After the first GPR failure, any cold start issues and I'd just replace it without any testing. It was 3 total when I was daily driving it, but the last one has held for the past 5 years now with limited use.
 

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Holy necropost Batman, you put up with that for over three years!!! That sure wouldn't fly up here, eh Jim?

I'm soooo sick of this weather.....-18*F this morning too :no:, my gorgeous truck is full of salt, oil cooler is pissing out oil until it warms up...:icon_rolleyes:, c'mon spring
 

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For what its worth, each year in the late fall I put on a new gpr so I never have an issue with it come winter time.
 

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For what its worth, each year in the late fall I put on a new gpr so I never have an issue with it come winter time.
Why not just replace the relay with one that will work for years instead of one every year? My Stancor is going on 11+ years now and others have had the same service life out of them. Some are also using one for a Western snow plow with good results.
 

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Why not just replace the relay with one that will work for years instead of one every year? My Stancor is going on 11+ years now and others have had the same service life out of them. Some are also using one for a Western snow plow with good results.
I was going to mention this as well, WHEN, not if, the current GPR fails I had planned on upgrading to the Stancor too.
 

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Whatever works for you, most seem to encounter a no start situation at the worst moment due to a bad gpr. Since I've owned this truck (12 yrs) I never had an issue, (I know, you haven't either). I also replace my cps once a year too, .......same reasons. These parts are cheap enough as it is anyway.
 

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I put in a Stancor and I've had good results with it, although I do keep my old GPR in the truck box to put back in, just in case. The only problem I have with the Stancor is that it's a pain in the neck trying to put one in on a Cali emissions truck, what with the shunt. I've got mine sort of jerry rigged, and it's not pretty but it sure starts up nicely.
 
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