More GP Questions

[mankypro]

Suddenly I'm having hard starts. Where before I could just turn the ignition and stomp on the accelerator and it took 2 cranks to start it, I need to sit on the starter for 10-15 seconds now.

It's 95 degrees outside. Not using block heater. The WTS light comes on like normal. I pulled a gp (this being the first time ever I've done this) and the tip is covered in black soot, bit the top of it has a fine whitish soot like material on it. When compared to a GP out of the factory bag the one I pulled looks structurally sound.

Before I pulled it I tried using my Ohm meter set to continuity test at 20 and couldn't get a reading from it. Sometimes when touching the terminal I'd get a 2 or 3 momentarily and then it would fall to 0 again. I think I may be doing something wrong here.

That said, I had the black lead on the battery neg terminal and touched the spade connector on the gp. Anyone care to help this newbie out?

I guess I could replace all the gp's and be done...

 

[Mr_Roboto]

No need to pull the GP's to check them. Pull off all the leads, then check for continuity between the top connector of the GP and any good ground.

If there is zero continuity then the GP is burned out.

You can do the continuity test with a test light. Alligator clip to 12 volts, probe to GP top connector (with wire unhooked).

 

[Diesel JD]

Do you have the factory glow plug system hooked up or a push button? I agree with roboto, test them with the light since its toggle/6.9 system. 7.3 system is more sensitive but for the 6.9 if it has continuity its good.

 

[mankypro]

Well, couldn't get my ohm meter to do the right thing and since I'd never pulled the gp's on this vehicle I went ahead and did it. Did 6/8 before I had to turn in for the night. 5 out of 6 so far were bad - tested them with a 12v battery booster. Well, seeing as there is a good possibility that the last two are bad - that pretty much solves the mystery.

I wonder if WMO can fark the GPs? Anyone notice a higher rate of failure with WMO?

 

[69dieselfreak]

im having the same problem with my truck so on the weekend i think im going to test the gp's and probably replace them since i dont know when they were done last im also running wmo but i think it might be in my stock lift pump also to get the fast start like i use to i just plug it in and it starts fine like it should

 

[mankypro]

I've done 1100 wmo miles so far on questionable oil. My rear tank is almost empty so I'm going to fill it with "known" WMO and hope that my smoke/lack of power problem is resolved. Note: I'm running 100% wmo in one tank.

I really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really, really don't want to replace my IP. If the next tank full doesn't make things better I'll do my injectors. Then I guess it's the pump - I'll have it checked for timing and advance, etc. Wish I could do it myself.

One of you IDI folks wouldn't happen to be in Colorado???? Teach a newb? Huh? I can BBQ like no one's business! ;p

Truth is the manual doesn't make it sound too hard to do. IS the only speshul tewl needed the pump rotator? If so I could get a new one mounted then take it to be dynamically timed - sure would save some moola methinks.

im having the same problem with my truck so on the weekend i think im going to test the gp's and probably replace them since i dont know when they were done last im also running wmo but i think it might be in my stock lift pump also to get the fast start like i use to i just plug it in and it starts fine like it should

 

[Diesel JD]

Unlikely. I'd rig up a manual toggle switch and use a set of 12V AC Delco or Bosch plugs if I had the old style system. New style or factory controller needs a set of Beru ZD-1A for the 83-86 system. You don't need any special tools to change the IP. The rotating tool would be nice but a 1" box wrench or a good adjustable wrench on the pump boss(not the lines or the return) and rotate the pump. Its nothing to be scared of really.

 

[david85]

The 1983-1986 glow plug controller will glow the full timed amount even if there is only one good glow plug in the set. The only time the glow plug light will not come on is when all 8 plugs are burned out. I would also strongly advise against using anything other than the OEM motorcraft glow plugs. I tried bosch and they did poorly. Wellmans were the worst. The only real difference is the Berus have a slower heat time making them safer for the standard 10 seconds glow time that the factory controller is set for.

Preform continuity test and see if you actually have any dead plugs. If so, all 8 should be replaced as a set.

Theres some info here that seems to be ripped from the ford manual:

http://www.garagenet.biz/forddiesel.htm

 

[Diesel JD]

David is right about using the Berus for the factory controller. My point is I think its not really a very good design, so I'd either take the opportunity to upgrade to a 7.3 style system with the Beru ZD9s or use an old 12V style plug with a manual toggle. The AC Delco number was 7G I think for the slow glow 12V plugs you want. Type in the 1978 Delta 88 Olds with the 5.7 diesel. It would be hard to burn those out with 12V going to them. Its the 12v going to the 6V plugs that burns them out, especially the 83-86 system which uses a latching relay and can leave those plugs on for a lot longer than those 10 seconds that it should if it sticks.

 

[mankypro]

I'm using zd-1a's for replacements. I have a factory controller that is under warranty from when I first had the truck brought up to speed about 8 months ago, so I use it. It hasn't had any trouble. I have a toggle and plan on doing the manual switch when time is sufficient - certainly before winter.

 

[69dieselfreak]

hey what is the procedure on bypassing the glow plug controler on the 6.9

 

[david85]

hey what is the procedure on bypassing the glow plug controler on the 6.9

I have a working OEM type controller, but I ended up using an old bilge pump switch for a manual override. It has the functions: Auto / Off / Manual. With manual being a momentary switch. I can hold the switch to the manual position for 5 seconds, then flip it over to the auto position and it automatically goes into after glow cycling mode. Having the off mode is handy for those times when I have to do wiring on the truck or a trailer (which hasn't happened since switching to LED trailer lights, but still a nice feature)

There are two ways you can bypass the controller.

You can go directly to the glow plug relay and bypass the controller all together, or place a switch on the 12V feed that activates the controller itself. Bypassing the controller completely will give you absolute control over the glow plugs and you can now burn them out if you wanted. Keeping the OEM controler means that if some one else has to drive your truck, they will not be able to burn the plugs out by mistake. You can turn the glow plugs off early, but you will still not be able to exeed the 10 glow time.

The disadvantage with going through the glow plug controler is that if your hand slips and you accidently release the switch during the pre start glow time, the controller will only go into after glow mode when you turn the power back on. I would strongly advise against using a toggle switch if you are bypassing the glow plug controller, a momentary push button switch is the safest here.

Something else to remember, is that this type of controller is just a dual bimetal switch that might as well have been designed before WW2. When mine failed I took if apart and its pathetic, can't believe they cost so much to relpace . But even more worrying is that when they fail, they can start to glow for a longer and longer time untill they will burn your glow plugs. Adding a switch to the OEM controller would give you an added safety net to prevent this.

The later system for 1987 and up is much better and can even detect when you have dead glow plugs, but you are looking at over $300 just to convert it over. It is a bolt on job, but a bit expensive to justify.

 

[mankypro]

Well results 7/8 glow plugs were dead. Geesh. starts like a champ now...

 

[david85]

Well results 7/8 glow plugs were dead. Geesh. starts like a champ now...

7 dead plugs will make it a bit harder to start lol.

Just keep an eye on it and make sure the glow time does not exeed 10-12 seconds. If the glow time starts getting longer, than your controller could kill your new plugs in short order. The beru plugs will easily survive a 10+ glow time, so unless the controller goes south, they will last several years at the very least.

 

[mankypro]

the light stays on for about 5 seconds normally, i'll be bypassing the controller here shortly after I do the injectors.