Are you having starting problems?

Does it continue to cycle after the engine starts?

What are your local temps like?

 

Try about 9 or 10 seconds on the glow plugs at low temps.

If you still have heat in the engine, glow plugs are not needed.

 

The glow plugs are designed to run on 6 volts. My '87 has a huge resistor on the back of the intake manifold to lower the voltage. If one or more plugs goes out, then the voltage goes up to the rest, shortening their life.

 

Alanart,
Welcome to FTE and the IDI diesel forum.

That is actually the controller/relay on the intake of your 87.

 

so should you buy them at napa or ford, how much do they cost???

 

If you are asking where to get the motocrafts, I ended up getting them the cheapest by ordering all 8 at once from rockauto with a 5% discount coupon code found online, and priority mail shipping.

No place locally around here could compete with rockauto.

 

If you have the time, online is the best deal for sure.

 

get them here for $9.99
7.3 Liter Diesel Motorcraft Glow Plugs - ZD 9
if you need ZD-1's, they have them also
6.9 Liter Diesel Motorcraft Glow Plugs - ZD 1A

 

It was $85 shipped to california for me for 8 #ZD1A from rockauto with the 5% off coupon you can find by searching google, so a little cheaper than that site.

 

cool. what site did you get them from??
we like to keep track of the priced the vendors sell them for.

 

Well Just got my first diesel two weeks ago, 1992 Ford F250 with the 7.3 in it. Run's like a champ but with cold days here I was having hard start issues After lots of research and reading this thread I learned how to test and repair the system. Problem child was a bad controller box, it wasn't shutting off power to the glow plugs at all, and as a result 5 bad glow plugs. Replaced the controller with a BWD and got all new Motocraft plugs and she will start now in 20 degree weather with no block warmer!

One test I found not listed here that did identify the problem for me was out of the Haynes diesel manual. It has a test were you unhook all your gp's and hook a light up to the test terminal of the relay. Turn on your key and wait to see how long for the light to go out. Check that against the chart to see if your controller is working. In 0 degree weather it should be between 15 and 30 seconds. This time is different then the wait to start light time.

This is the test that showed me the power was staying on! Replace the box and move on to the next problem... bad glow plugs from the power being on and frying them.

In doing all this work I found I had two glow plug connectors with no boot at all and a couple others with cracks in the boot. I have searched all over and cannot find new connectors or even a new gp harness. Any suggestions or links would be greatly appreciated!

Thanks!
Ed

 

Welcome Ed. These guy's carrier replacement bullet connectors. Look under glow plugs.

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7.3 L Ford Diesel Fuel Injectors Fuel Pumps Accessories

 

I can help on glow plugs and a controller too.

 

Hey 9473 thanks for the link, I am going to order some of the boots.

Ok so to refresh, I have 1992 F250 7.3, I changed out the bad glow plugs and the controller box and fixed some bad/loose wiring. GP's seem to be working fine now and the truck is firing right up after about 10 seconds of "wait to start" light in 30 degree temperature.

New problem is I noticed today that sometimes the gp's continue to cycle for up to 20 seconds after the truck is running! By cycle I mean controller click on/off, not only can you hear it but can see it on the volt gauge.

I know the previous owner changed out the ignition switch, the tumbler itself. I know this because I have three separate keys for the truck, door, glove box and ignition. Also I have had problems with the tumbler locking into the off position properly and the whole thing seems a bit looser then it should be.

My question... is this gp cycling after truck is running inherent to a known problem? or Should I change that ignition switch asap and see if that fixes it?

Once again any help is appreciated! I am really worried that this cycling is going to ruin my new $140 controller or some of my new gp's.

Ed

 

It is normal for the relay to cycle after startup. It helps the engine to stay running when is is cold.