I have been having a hard starting , and smoking prob on cold starts lately my questions is i see 2 relays whick one is for the glow plugs and what is the other one for is both for the glow plugs the one closer to the firewall has current coming out of it but the other one does not please help , i smoked everyone out of the parking lot this mornin when i got off work, once it finely did start.

 

If you open the lid where your fuel filter is located you have a solenoid, from age the solenoids will split and fall apart. On the drivers side fender you have a timer relay. Depending on mileage you could possibly have a glow plug not working.

 

Which of the two solenoids is for the glow plugs the one up under the fuel filter cover or the one behind it.

 

One under filter cover to the left when you lift the lid.

 

well checked relay has power going in but none going out were is the best place to get a solenoid, when it was at the dealer getting the trans worked on he told me it had a solenoid put on it at 20,000 now it has 41,000 so i think i will stay away from the dealer.

 

A good electrical shop can help you out. The string of events: check your fuses, you have a timer relay on the box located on drivers side fender, then a solenoid under the fuel cover. 1 or 2 bad glow plugs can make for a hard start.

Hope this helps.....not sure on a solenoid located to the rear, near the firewall, maybe another 7.3 owner can chime in since I sold mine and now have the 6.0L

 

I just picked up a glow plug relay yesterday for $30 at NAPA. I was having trouble starting. Actually, it wouldn't start at all unless it was in a heated shop(which I don't have). Once the new relay was in, it fired right up. No muss, no fuss, just running.
Fullcrew7.3

 

Sounds good ...... just remember any hard start is not normal and when things are working right, the 7.3 will fire right up. Depends on your miles but replacing glow plugs before you need them is a good idea. This summer when you have time slip in a set of plugs.

 

at what mileage did you guys replace your glow plugs and relays at?? did u do it or did someone else and is it hard to do?

 

I did an informal poll here on the site regarding how long glow plugs last. Most go about 100K You might get more but will run the risk of problem removals from carbon buildup on the tips and as Maxium4X4 stated, it would be better to plan the project for good weather. I haven't done mine yet but I've heard the project complexity described as being a fair but harder than spark plugs. It's harder mainly due to access issues and problem removals, plugs breaking off etc. Not sure what year it was but I've heard of some having problems getting one of the valve covers off too, something to do with the firewall etc.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-comfficeffice" /><o></o>

As for factory glow plug relays, they are a known problem. I'm on my fourth one in 60,000 miles. I didn't know about this site and bought my first one out of warranty from Ford. They have replaced it twice in the last 3 months for free. The dealer I work with says they'll keep replacing them until on lasts a whole year and he's not surprised at my problem. Maybe you'll have better luck with the Napa relay. If not there’s a post here where a guy bought one from WW Granger that is really well designed, silver contacts, rated for 100 amps, lower current draw for the relay controller. That will probably be my next one. Start paying attention to your volt/amp meter on the dash or the dome light dimming when you first start the truck for the day. They are easy indicators of the relays functionality. In the morning my voltmeter is well below normal when heating the plugs. Mine slowly rises as the plugs heat up but some say their meter stays down till the trucks started. The relay can stay engaged for anywhere between 10 and 120 seconds depending barometric pressure and oil temp.

 

The timer relay and the solenoid are easy to access. My thought on glow plugs are I would do them in the summer when it is nice and I can plan a weekend of putting the truck out of service on or around 80 thousand miles.

Testing the plug will tell you which ones are working. Now in reality, you will have to replace them at one point in time, so waiting for the coldest time of the year to find out is not the best situation. Once a plug has burnt it does start to collect carbon, which in turn makes the removal a royal pain. If you do find yourself trying to remove a plug that has thick carbon build, take your time and soak with a cleaner over night to loosen the carbon.

If you do snap a glow plug off that is a whole new situation.

So take your time. Inspect the wiring harness under the valve covers.

 

do u have a napa part number i can use to get me one all the local part stores around here including napa said they could not get one, i do not want to go to the dealer its already had one from the dealer put on it and i like to try a different one.

 

I'm just wondering how this GPR is supposed to work. The past couple of weeks it's been getting do3wn into the 30's at night and the truck doesn't want to start, unless I plug it in for a few hours. When I turn on the key, I hear a couple of "clicks" from under the hood and the voltmeter starts slowly coming down. The WTS light comes on for a few seconds, then goes out. The voltmeter continues it's downward decent. If I don't crank it, the voltmeter will just keep going down, even after 10 minutes. Finally, when I do crank it, the voltmeter will come right back up to mid-scale and all is well.

So...I'm thinking that number one, my alternater is working fine. I'm thinking that the GPR is not disengaging the glow plugs and they are staying on after the 2 minutes when they should shut off, at least that's what I've read. Since it's also been very hard to start when cold, could this have burned out the glowplugs? Do the glowplugs only "kick off" when the engine is running?? Is it normal for them to stay on with the engine off as long as the key is on? Is there any way to test to see if the glowplugs are indeed remaining on?

The batteries are both heavy duty Motorcraft and are less than a year old.

Thanks.

 

Now do not quote me but from what I remember on my 95 the WTS light would go off and the plugs would still cycle for another minute or longer when running. You will actually see your lights pulse when the truck is running from the current draw. Another thing to consider is your fuel heater. This could make for a harder start. A burnt plug or plugs not working will give you a clue in 45 to 50 degree weather on a hard start.

 

I can't answer your questions with the knowledge that some of the wrenches here can, but I can say that my 99 acts like yours except, The relay does not stay engaged for ten minutes. After the click under my hood the voltmeter goes down about 2 to 3 volts then slowly rises to the normal point. I have tested my relay with a handheld voltmeter and the relay does disengage after a time, whether I start the engine or not. That time has never exceeded 2 minutes, but I don't know what triggers its disengagement. Maybe a heat sensor in the cylinders or current draw sensor for the relays??? I'd like to know the answer too.

As for testing, you'll need a voltmeter. When the glow plugs are engaged, there will be battery voltage on the glow plug side of the relay. On mine, when standing at the front of the truck, the glow plug lead is the large lug at 3 O'clock with two wires going to the valve covers (one to each glow plug bank) There is always voltage on the large lug at 9 O'clock, it is the battery supply lead. The other two smaller leads are relay control leads. On mine, the one at 6 O’clock always has voltage on it and the other at 12 O’clock only has voltage when the relay is disengaged (meaning it goes to ground when calling for the relay to close) I doubt yours is engaged all the time though, if it was, I’d expect your glow plugs to be toast and your wiring would probably be burned to a crisp.