So lately with the nights getting cooler, 40-50 degrees, the truck doesn't want to fire in the morning. But after trying to crank a few times, maybe a total of 20-30 seconds, it will fire up. All the while while cranking, tons of white smoke is pouring out. (Wish I could blow that much black smoke ) The glow plug relay was just replaced, and I checked to confirm and I have power coming out of the relay when the key is turned. The glow plugs, EOT sensor, and valve cover gaskets were replaced 2 years ago. The UVC harnesses were checked at that time also and fucntioned OK. So I guess I could have an issue somewhere between the relay up to the glow plugs at this point. Would so many glow plugs or UVC harnesses go out at once that it would cause such a hard cold start? What would I want to test or look for? Also, if I shoot a few shots of ether, it still doesn't fire. That's odd to me because when I first bought the truck, the previous owner installed an ether system and as soon as i would give it a spray it would fire.

Isn't there a fuse associated with the glow plugs, #22 I seem to remember reading about?

What about oil or fuel? If tons of white smoke is pouring out while cranking, I would figure it's getting fuel. And if it's shooting fuel, I imagine the HPOP is working and firing the injectors, correct? Or could I have a draindown issue? Or IDM issue?

I also read something on here about the ICP sensor, unplugging it and seeing if the truck fires. But could that be affected only on cold starts?

CPS is fine I believe because the tach moves while cranking.

Overall performance is good once running and hot starts are fine and in the warmer weather all summer the truck started perfectly, which is why I would lean towards the glow plug system. What do you guys think I should do first?

 

IMO, you are on the right track...it's in the GP system.

You need to make sure the GP's are staying on long enough to get the job done. If your battery voltage is too high (1 or 2 weak GP's) or a bad EOT or BARO the GP's will turn off too soon.

Does the engine miss and shake after it lights up? (Weak/bad GP's)

Watch your volt meter, Does it swing far to the left and stay there for a while? At least
30 seconds.
The GP's are still heating even if the WTS light is off, Let them 'burn' for 60 seconds or longer before you attempt to start it.

Fuse #22 protects the GP's, If it's popped...the engine will never start. It protects the power supplied to the PCM too.

You can cross out the 2 big lugs on the GPR with a screwdriver for 30-45 seconds...
jump in the truck and start it. If it fires up OK the GPR is weak/bad or the wire connections are loose/corroded.

 

I know that the glow plugs will stay on longer then the WTS lamp. When I tested the GPR yesterday I had a steady 12.some volts on the large outboard terminal for about a minute. After that minute or so the voltage was gone and a big click and the relay disconnected. Then I tried to start and it took like 20-30 seconds of cranking to make it fire, all the time pouring out tons of white smoke. The engine seems to run fine after it fires.

 

Try jumping the relay ,,most GPRs don't last very long ...

Even with 12 v on the output ,,It may still be bad ...not able to carry the load ....

 

almost sounds like bad glow plugs have you tested them with an ohm meter to verify they are good?

 

No I haven't tested them yet, can I do it just by unplugging the harness on the valve cover or do I need to remove the valve covers?

 

Saved from TDS ...On each valve cover connection there are five pins. The outermost pins (pins 1 & 5) are for the glowplugs. They should not have continuity with each other or the center three. The center three are for two of the injectors in each bank. The ohm reading between each outermost injector(pins 2 & 4) and the center pin (pin 3) should be about 2 ohms (if I remember correctly . Pins 2 & 4 should also not have continuity with each other. The undervalvecover harnesses are just replaced as a "unit" if they are bad (there are 4 of these harnesses per truck, 2 per side

 

Injectors should ohm at 3.2-3.5 using the center pin as ground 0.5-0.6 ohms for the glowplugs using the neg on the batt.for ground

 

I have the exact same problem with my truck, cranks but all that happens is white smoke. If you figure yours out, let me know

 

Yeah, all theses ohm readings I'm going to have to look into. I've been in Vegas for a few days so now I got to start looking at the truck again.

 

I'm willing to bet you have at least a few bad glow plugs. I've never known any to last two years, personally, and my family and I have owned six diesel vehicles over the last four years... I would definitely recommend bosch glow plugs. autolite will last half as long, and tends to break off inside. I don't have any experience with OEM Motorcraft plugs, though. maybe someone here knows whether they're any good or not.

 

I suspose bad glowplugs is a possibility, this being the first diesel I owned, I don't really know how long they last. Personally, I would would think they should last longer, but.... I know the system wasn't working about 2 1/2 years ago when I bought the truck and then I changed the plugs, relay, and valve cover gaskets and the system worked perfectly. The plugs I bought last time I got off of Ebay, I believe they were made by WAP Inc. supposedly made in USA and the same plugs the military uses.

 

So I did some ohm tests today. Each one of the connectors had similar results. Here's my findings:
Glow plug pins on head to battery negative, .5-.6 ohms
Glow plug pins on head to engine ground (I used the turbo exhaust housing), 5,000,000-23,000,000 ohms
Glow plug pins on head to the center ground wire on the harness, 109,000-123,000 ohms
Center ground wire on harness to battery negative, 110,000-112,000 ohms
Glow plug pins on harness to relay outboard stud, .1 ohms

According to the service disc, the glow plugs pins on head to battery negative are in spec, and the glow plug pins on harness to relay outboard stud are in spec. The rest seem a little odd to me. Something seems wrong with the center ground wire in the harness?

 

Your GP's are good.

This indicates to me that your battery grounds are bad. You should have seen 5-10 ohms

This test is going through the IDM circuity and should be a higher reading...but not that high. Maybe the battery grounds too?

This should be infinity or a very low reading. Bad battery grounds again. I see a pattern developing here.

Should be infinity or a very low number. The wire(s) are OK.

 

Engine grounds are flaky at best to measure unless really clean contact area.

As mentioned above use a screwdriver and short out the two large studs on GPR for 30 seconds then try starting. My bet is just a bad GPR. Cheap ones will fail really fast.