Happy 4th

99 f250 7.3 101k California truck
Scanned it said #1 glow plug did not clear the code

But now the check engine light is off again

Questions
Harness issue ? Glow plug bad at 100k ?
Glow plug controller ?

Start at glow plug work way back to GP CM or in reverse ?


Replacement Do all 8 or just the bank of 4 ?

Thoughts on replacement brands

Accurate diesel glow plug replacement kits any good, will they last ?

Or go factory glow plugs

What about Felpro gaskets

I heard about another brand of GP CM

 

You could ohm out the plugs and associated wiring from the 42 pin connector in the engine bay. If any read open they need to be changed with ONLY Motorcraft glow plugs. The aftermarket ones have been known to swell in the head, meaning pulling the head is the only way to get them out. If you only have issues with one or two on the same bank then I would just do that bank, unless you really want to go ahead and do them all.

One further thing to check is the connection to the UVHC these are known to work loose over time, also look up the "50 cent mod".

Some time and a multimeter could save a lot of work further on.

 

Thanks for reply
I tried to look for the 50 cent mod
Could I please be educated on this

Also any tips on which direction to start glow plugs to GP CM or GP CM to GP

Just a interesting tip I was reminded of
We had extreme heat here in California the day the check engine came

Could it be a connector swelling issues

 

The 50 cent mod is where you put a (ground down on one side) quarter under the clip to the connector on the UVCH to help stop it coming loose. The 42 pin connector to the GP's will let you know that the wiring harness over the engine and the UVCH's wiring is good if you get a good read on the GP's.

Another thing to check is where this wiring harness goes over the valve cover, it has been known for this to get worn there and expose some wires, causing them to short on the VC. If it isn't worn through, some wiring look will help protect it from future damage.

I am not saying it can't happen, I am far from a guru on these trucks, but I haven't heard of a connector swelling from the heat? Maybe someone else here has and can shed some light on the matter.

One final thing would be to check for any burnt pins in the wiring connectors going to the VC's. These can be an issue, if you have any it should be pretty obvious when you start pulling connectors.!

 

ok thanks so much for your help I learning but more dangerous I think
Here is where I get lost, I am good with basic mechanical but electrical issues over my head testing with a meter I really do not know what I am looking for
I had a great diesel mechanic, which now has moved to far away to work on my trucks
As with most he would do the work while I was at work
So I am learning with every ones help



So uvch connector is on the valve cover or at glow plug control module/relay

About the swelling my mechanic said the harness's come loose at the valve cover due to a poor original design, new ones have a better clip due to heat

Here my diesel list neighbors hate me
95 E 350 7.3 cargo 88k
99 f 250 7.3 4x4 ext cab 101k
01 f 350 7.3 2w crew 346k best truck ever owned
04 excursion 6.0 typical issues
non diesel
02 f150 4.6l ext cab 86 k fuel supply issue can't find it
01 dodge 1500 ext cab 4 x4 97 k evap issue cant smog it
96 ford explorer sport 101 k great truck
67 rs/ss camaro Red with black rally all original 47k

 

That is correct!

 

This where the quarter goes ?

just checking found this site best price I have seen for ford MC

These are the correct GP
https://www.dieselfiltersonline.com/..._for_8pcs.html

 

On my phone or i would post links for you. Type "quarter trick for 7.3" into Google and watch several videos of how to

 

67 Camaro - Go to u tube & type this in -2001 F350 7.3L Turbo Diesel, UVCH Shows the procedure

 

Tell us a little about your truck. Is it tuned? If you were making serious boost that can cause the cel to come on and shut off shortly after.
The CEL can be a very goofy light and sometimes may not even be directly related to the engine. I had a fuel pedal problem and it would cause my CEL to come on.

 

1. The glow plug wiring does not come within a country mile of the 42-pin connector, not even on non-Californiia trucks. All evidence says you have a Glow Plug Control Module because you have a California truck, and you are getting a specific glow plug code. Those with a Glow Plug Relay can't get this code.
2. Testing the 42-pin connector (UVCH link in my signature) is still a good troubleshooting method. If a UVCH is bad, it will likely show up in the injectors as well. If the injectors read bad - confirmed bad UVCH. However... if they read good, that doesn't yet clear the UVCH because it's the outer edges that lose connection first - where the glow plug connections are located.
3. As mentioned, the outer-most contacts on the 9-pin connector to the valve cover gasket are your glow plugs. The two closest to the front of the engine, and the two closest to the rear of the engine. You can pull the connector and ohm out those four contacts. They will likely read close to a dead short, depending on the quality of your meter. Suffice to say, they should all read very low on an ohm meter, and very close to the same front-to-back.

 

Hello back home
Thanks to all for the replies and tips and input
The 99 f 250 7.3 101k is chipped it is a roll along package, 6 in lift black pro comps
Just went through the front hubs , rotors and wheel sensors
Truck has been through 2 water pumps 2 factory pumps

I ran a scan on it it said glow plug 1 , but the light went off hence my post

Interesting thought about the pedal assembly, I had 3 in my 01 7.3 it was throwing the Cel

 

Also these are the correct gp?
These are the correct GP
https://www.dieselfiltersonline.com/..._for_8pcs.html

 

Looks like that site is selling ac delco. Haven't heard of problems specifically about AC delco but it is pretty much a given around here that this is one of the items you only want to use OEM. After market have been known to swell inside the head and when it comes time to replace you have to remove the head to get them out. Motorcraft ZD-11 is the part number. I got my last set at a local parts store (I think autozoo) came in the motorcraft bag. Clay sells them too. Motorcraft Glowplugs ZD-11 - Ford 7.3L (94-03) . If I'm not mistaken they are actually made by a company called Beru but definitely go OEM on this one.

 

here is the item