Hello everyone! The problem I'm having is that my truck starts and runs fine at lower elevation (around 1000') and warmer temperatures (60-80 deg.) However when I go hunting at higher elevation (around 7000') and leave the truck parked for a day or two at the cabin. it becomes very hard to start. Temperatures there run in the 50's during the day and drop into the 30's at night. The truck cranks and sputters but won't fire. It belches alot of white smoke while cranking. I wait till the wait to start light goes off and actually do this several times as it takes about 15-20 mins. of cranking to get the truck started. All this cranking also puts a hurting on my batteries. When I turn the ignition key on I can hear some type of relay click on and the wait to start light comes on. I'm not sure if this is a glow plug related problem or a problem with my batteries in the relatively cold weather. Once the truck starts it runs fine and if we drive around the ranch for 15 mins. or so and I kill the engine, it will start up just fine. Needless to say this is a hard problem to diagnose here in Hawaii , as most of my friends drive around down where it's warm, and I don't want to spend a fortune at the dealership. Any help would be greatly appreciated! Thanks -
Duane

 

Sounds like a simple glow plug problem. Most likely a relay, but could be a few bad plugs. Have someone turn the key on and check for power between the two big lugs on the glow plug relay. (next to the fuel filter lid) The glow plugs will cycle way longer than the wait to start light. So if you are getting power between the lugs, and it's staying on, it's probably a glow plug or two, or more. LOL You can ohm them out in the valve cover connectors. The glow plugs are pins 1 and 5, in other words the outside two pins. The three pins in the middle are injector pins. I think you are looking for above 3 ohms and below 14 ohms. If I'm wrong, someone will chime in. Anyway, first check the relay. Turn the key on and just let it cycle, the truck should fire right up if everything is working. Maybe you just weren't waiting long enough. And for more info, I believe there is a sticky thread about hard starting, white smoke at the very top of the topic list. Check that out too. And above all else, welcome to the forums. I think you will really enjoy it here. The people are great, and very sharp on these trucks.

 

ditto on glow plugs, sounds like most likly the relay to me. at 50degrees if 4 of the glow plugs were working it would probably fire first or second try

 

Thanks for the info and quick comeback. I checked the relay, there is power between the two big lugs even with the key off. When the key is turned on there is no change in voltage across the lugs. When the key is turned on, I can physically feel the relay click on and it remains on for about a minute after the wait to start light goes out. I can then feel it click off. I checked the resistance of the glow plugs at the connectors and on the 200 ohm scale I am reading 00.5 ohms across the outside two pins. I assume this is 5 ohms which should be within tolerance. I am wondering if the problem is with my batteries? I read 12.48 volts across both of them with the engine off, but they are a couple of years old. They are Sears Diehard Gold series batteries. There was a fair amount of corrosion on the positive terminal of the passenger side battery which I cleaned off as well as all of the other terminals. I also made sure the terminals were nice and tight. I know that the voltage reading on the batteries means nothing really without a load. Would a battery load test be my next course of action, or perhaps better batteries? Recommendations? The truck again starts and runs fine here at lower altitude and warmer temperatures. Thanks again for your help!

 

No expert here but the two outside pins for glow plugs need to be tested each, not across both pins with VOM. Put black lead on ground then red lead on one or the other outside pins and that will give you the correct resistance of that glow plug. Also when checking GPR with key off put black lead on ground the red lead on one or the other big lugs. With Key OFF power should only be on one of the lugs and with WTS cycle power will be on both big lugs.

Jim

 

Jim-
Thanks for the information, I guess I was testing the relay in the wrong way. When I tested it in the way you described it showed open with the key on. Strange that you can even feel it click on, yet no contact is being made. I also didn't realize that there are two connectors per valve cover for my glow plugs. I only tested half of them before. In checking the rest they all tested good though. Now I only hope I can find a relay to replace the broken one. I sure am grateful for all of your help and for this site. Thanks again!-
Duane

 

needing to see if anyone has any ideas on why when its cold my 96 f250 diesel will be a pain to start. batterys are good and at times it will want to start but today it now just cranks after trying to start it.

 

Dont do what i did and try to use a ford starter relay. It will bolt right up and everything. But the glow plugs will stay on all the time when the keys on and burn out. Luckily i cought it in time with my test light and saved the glow plugs. The ford starter relay is case grounded and the gp relay is not. therefore when u give it power with key on, it turns on instead of waiting for a ground from the computer.