Alright guys awhile back I found out that my fuel bowl heater was unplugged and presumed not working. With the weather getting colder I am having problems getting her started. I will have to cycle the keys multiple times and even then it takes a min to fire up. If it helps any the truck also blows a decent amount of blue smoke for the first few minutes of being started and usually a big white cloud with it. My dad has a 7.3 as well and he's hell bent on telling me that it's my fuel heater but I see allot of people saying you don't even need that for cold starts? I think it has to be something with the heating because once the truck is warmed up it runs fine. Bad glow plugs? Fuel heater? I'm not sure where to look. Thanks in advance

 

You do not need the fuel heater for cold starts, or need it at all for that matter, unless you are running in extreme cold temps. Start by checking to see if the glow plug relay is energizing when you first turn the key on. You should get juice to the 2 large posts on the relay. One should be hot all the time, bot should be hot when the key is in the run position for up to 2 minutes. If that Checks out, check the glow plugs. A quick way to check, is with an automotive test light. Clip the lead on the positive post of the battery, and touch the pin in the valve cover gasket for the glow plug. If the Light comes on, the gp is probably good, no light indicates a bad GP. The Pins in the harness are GP- injector-common- Inj.- GP. If you have a Superduty type valve cover with just 1 plug the GPS are the 2 outer most pins on each end. If you find some bad GPs, replace them with Motorcraft/Beru ZD11 glow plugs. After market ones don't seem to last, and some swell in the head when they burn out.

 

OK I'll check the relay when I get home and I have the regular valve covers so are the GPS still on the outer most pins?

 

yes, and when you turn the key the PCM will run the GP's for a minute and a half. No need to cycle the key, I usually wait for ten seconds after the 'wait to start' light goes out before cranking. You should also hear a click and a drop in voltage on the gauge after turning the key.

 

i have to agree with the guys that is a glow plug problem. even in extreme cold temps the fuel heater is not needed if you run good fuel.

 

Well all the glow plugs checked out on the valve cover harness but I think it might be the relay, I have power on one side but not the other when I turn the key. I think I'll be replacing it

 

I bought a standor and have never had a problem.

 

Well guys I checked again this morning since my truck was cold I figured itd be a good time to do so and turns out the relay is good. I got power coming off the other post when I turn the key. So the relay is good and glow plugs seem to check out. What do you guys think?

 

Old, slow starter?

 

Well my starter and batteries I think are old and a little slow but it starts up just fine when it's warmed up

 

For *****s and giggles, "jump" the 2 large posts on the GP relay for 30 seconds with a screw driver, being careful to touch only the 2 large posts, then try to start it. it fires up he contacts in the relay are fried, allowing juice to flow, but not enough amps to heat the gps, and the relay needs to be replaced.

 

that is why i always recommend using an add on glow plug light instead of the light in the dash to any diesel owners i see that do not have one yet.
with the add on light connected to the output of the relay, you know for sure if the glow plugs are getting power or not. .

 

Power across the two large posts doesn't mean the contacts can handle the load . Clamp a jumper cable clamp on the two large posts & try starting it

 

^^^^ +1; another test to confirm this is to turn the key to RUN, and measure the voltage from each large post to ground. The GP-side post can be a LITTLE lower than the always-hot post, but if the DIFFERENCE is more than 0.3 volts, then the relay is bad. Yes, it's connecting, but not supplying sufficent power to energize the GPs.

 

If the GPR is OEM style then it has a rotating disk inside. Every time it energizes the disk is suppose to rotate, sometimes it doesn't. Over time the disk can become pitted and cause poor contacts.

Here is a picture of that disk ...