Glow plug controller questions

[The FNG]

Is there a trick to taking the plastic pieces off of the glow plugs to get to the bullet thing? Just want to be sure before I break something. Also, I am assuming I will need to remove the intake up to the turbo to reach most of the plugs...

 

[The FNG]

Ok I figured out the above question myself, but when you test the glow plug, do you put the lead on the bullet tip or do you leave the harness attached? Without the harness, I was getting OL on my meter from bullet tip to battery terminal ground, but I got 1.2 ohms with the harness connector attached. Which is correct? All 8 ohmed out at 1.2 ohms. I also found a wire that had the insulation chewed off, so I will fix that and see if it fixes the issue.

 

[franklin2]

Disconnect the harness when checking. They are just heating elements with very very low resistance. OL means that one is bad.

 

[The FNG]

Disconnect the harness when checking. They are just heating elements with very very low resistance. OL means that one is bad.

Great...........ok, we'll I have a lot more work ahead of me then. Thanks. I read that the timing for these trucks is supposed to be at 8.5*-9* BTDC. Is that correct?

 

[argve]

Yep as stated you need to check with the harness off. Otherwise your meter can "see" a path to it's other lead and will give you the results of that test combined instead of just testing the one single glow plug.

 

[The FNG]

Ok, so further investigation shows that 7 glow plugs are at 0.2 ohms and one is at OL. However, I found 8 autolite glow plugs in place of what was supposed to be motocraft zd9's. I'm not very happy with my mechanic right now. So I will replace all 8 glow plugs with the correct ones. Is there a method to getting the rear 2 on the passenger side out without removing the turbo?

 

['94IDITurbo7.3]

swivels is what most used. i just accepted the fact that it was gonna be a pita and just used an open end wrench and got comphy lol

 

[The FNG]

Ok, I was just wondering if there was a special trick. Also, does anyone know a reputable shop that would be a good place to get the timing on my truck checked? It seems relatively ridiculous for the average guy to do it himself with the cost of all the timing light stuff you need. I would be willing to travel to Portland if need be.

 

[madpogue]

O However, I found 8 autolite glow plugs in place of what was supposed to be motocraft zd9's. I'm not very happy with my mechanic right now. So I will replace all 8 glow plugs with the correct ones.

Um, wouldn't it be your mechanic who would be replacing the glow plugs with the correct ones, at her/his expense? Remind him that he's getting off easy, compared to having to remove a cylinder head to remove a swollen-stuck Autolite plug, and compared to being investigated for fraud.

 

[The FNG]

First off, this was over a year ago and secondly he no longer works at that shop. I will be doing it myself this time for a number of reasons including money savings. I like the idea of and find comfort in knowing how to work on my rigs.

 

['94IDITurbo7.3]

in this situation i would honestly be the one taking the plugs out. we all know what autolites can do in the heads. they might not know/care when to take it easy, whereas we might. yeah pulling the heads might be put on their dime but i would just rather not have the heads off if i can help it.

 

[madpogue]

Well at the very least I would get them to pay for the Motorcrafts, and remind them that they're getting off even easier, not having to do the work.

 

[The FNG]

It's a lot of money to replace them, but I'm really not out to get them. The shop is 45 minutes from my house and it would just be more of a hassle than it is worth. It's going to be hard to prove that I told him to put zD9's in anyway. I just want my truck to run the way it should.

 

[The FNG]

I've got new plugs on order, $65 for 8 zd9's to my doorstep. Best deal I've seen. I was doing some digging and found that some of the temp sensors may have to do with the glow plugs. I thought that the glow plug system was run from resistance. As the plug heats up, the resistance increases until the controller kicks off at some point. I was trying to figure out my cold advance/fast idle issue.

 

[argve]

On the early 6.9's 83-86 model years if I got the end date correct to use a water temp sensor to determine glow and after glow time. Now the solid state design that was in the 87 and later IDI's uses the voltage drop seen to make the determination on when to switch over to After Glow.

Now for the a problem with the cold idle/timing advance solenoids they are controlled by a temp switch on the passengers side of the engine just next to the upper water water neck / t stat housing. It's a two prong switch that will open up when the water temp is 112 degrees. it is wired to the glow plug controller but is only in parallel with the 12 v switched line and it just allow positive 12 volts to be seen at the cold idle/High Idle solenoid and also the timing advance solenoid. I haven't met a cold advance solenoid that could actually push the throttle up, but has enough umph to hold it up if you bump your foot off the pedal. It's located on the passengers side of the injection pump and has if memory serves one wire to it as it grounds through it's mounting, the timing advance solenoid is located inside the injection pump top cover.