so my starting issues form before have been resoved i pluged the truck in last night ans she cranked right up so i know its a glow plug issue. it sat at work all day and when i came out it didnt want to start took alot of cranking and finnaly turned over with loads of white smoke. i have read the sticky here, but it brings me to two things the pugs ( but they were working last week at least some of them) are bad or the GPR which i just replaced last month! so i cant imagine its that!!! also i have noticed my voltage shoots straight to normal now and no dimming for 90sec. so i know the glow plugs arent even cycling
so where do i start?
thanks sorry for the long post

 

Jump the two big post on the GPR in the morning fo 30sec and see if it starts then that tells you if it's the GPR or not

 

jumped posts for 30 sec and she still didnt want to crank over...only way shell crank is if shes plugged in. I cant imagine all my glow plugs are bad??? what else could it be??

 

So your seeing "no Load" or drop on your battery gauge when you have the WTS light? Did you have that indication before you changed out the GPR?

 

Just confirming... the starter cranks the motor, but it won't fire. And "plugging in" is the engine block heater, not putting the batteries on charger?

If the starter is cranking the motor well, but it won't fire unless warm or the block heater has been plugged in, AND you're not seeing a significant voltage drop with the WTS light on, then it sounds like glow plug system. If you've had the batteries on charger to get started, then you problem might be batteries.

If its the glow plug system, try putting a voltmeter on the glow plug regulator and ground. With WTS light on, you should see: a) +12 volts (or pretty close) on the low-current signal wire to the GPR, b) +12 volts on the large terminal from the battery, and c) +12 volts on the large terminal leading to the glow plugs. If you don't see signal (a), then something is wrong before the GPR. If you don't see +12 V main feed, check connections back to the battery. If you see signal and feed, but no output (c), then either the GPR is bad or its ground is bad. Worthwhile checking the ground before condemning the GPR. If you see +12 V output (c), then signal and feed are working, and the problems is downstream... glow plugs or harnesses.

If you have +12 V feed to the GPR, shorting (or rather manually bypassing) the GPR should get you started, but won't tell you if the problem is signal, GPR, or ground. If you don't have +12 V feed, then shorting won't do a thing.

 

ya...batteries are good, just had em tested. I also just replaced GPR a month ago when i bought the truck...thats whats sending me for a loop! FORD actually did the replacement. when i turn key to on position i hear the TICK which im guessing is the GPR engaging?? but once "wait to start" goes off she just cranks and cranks but wont fire over....unless she has been plugged in! I dont have the volt tester but will do my best to get my hands on one!! This just came about a few days ago...but before this happened when she would fire over my voltage gage woul hang out just about 8 for a couple mins and then once the glow plugs shut off it would bounce up past mid more toward 18...now once she cranks the gage immediately shoots right up as if plugs were never on???

 

The WTS light is just an idiot light. Usually, you need to cycle the plugs longer than what the light is on for (the GP's are on for 90 sec or so IIRC).

The easiest way to ensure the GPR is working is to jump the two big terminals with a scewdriver which you've already done...

I'd buy a multi-meter (you can find them cheap) and check the resistance of the GP's. You can check this by ohm'in the outside pins of the UVCH's. The resistance should be around .3-.9 ohms. Someone fill me in if I'm wrong on this.

Sounds like Ford replaced the batteries... Make sure the grounds are nice and tight. I've had equipment worked on before where they neglected to get a good battery connections which only showed up during cold starts.

How old is the starter? Starter's tend to lose their rpm capability as they get older. I replaced mine 2 years ago during the summer and I noticed a huge difference in cranking rpms with the new one. Just a possiblity as these engines have to turn over fairly fast to light.

Since it starts just fine when plugged in, there's only a handful of issues that it could be. I'd start with ohm'ing the plugs and see if they are doing their job.

 

Yea i would ohm the glowplugs out. farm69 is right they are the two outside pins on each vc plug-in, 2 per vc. but they should measure between, something like .5 to 7 ohms is good. but if u have a bad one it will measure something like 65 ohms or 1000, thats bad and needs to be replaced.

 

Here's a pic of the GP system...
Like Farm69 said, check, verify all your connections...
Depending how cold...take a time hack on how long the GPR "clicks" on and then "Clicks" off...don't try to start it....doesn't seems correct that the battery needle will go from 8 +/- and then run upward during the crank to start...my Plugs stay on a lot longer. GP time on is a factor of EOT and is PCM controlled.

 

The diagram above does not show it but there is a fuse link where one of the big lug wires on the GPR (hot all the time) goes over the the starter relay. The fuse link is located in the wire close to the starter relay. You are going to need a volt meter or circuit tester to check it out. There should be 12 volts or so at the connection at the starter relay and the same voltage on the big lug (single wire) at the GPR, key off. If not then bad connections or blown fuse link.