Engine coolant temperature gauge.

[wildbill963258]

The problem is it doesn't stay in one area or another area of the gauge for more than a couple of days. Some days it reads around the r, m area and some days like yesterday it will hang around the n. I'm thinking my thermostat is showing signs of age and is sticking closed a little longer than it should be.

 

[wildbill963258]

The only reason I'm thinking it's an issue now is because I'm having to go under the hood and fix my uvch again. And the right bank that has the aftermarket VC gasket and uvch is just fine but the left one even with a good OEM gasket and uvch like I explained earlier in this thread doesn't seem to want to VC gaskets and uvch's for very long. Something is breaking down the connection on that side of the motor and the only thing that comes to my simple little mind (plus I work with plastic everyday) is heat.

 

[superpsd]

I run the motorcraft 195° stat. I would never want to run a hotter stat. I rather keep things a little cooler. The 195 actually starts to open at 175ish°. My 7.3 when lightly loaded and idling stays right around the N which shows 176° with a IR thermometer typically. When I heavily fuel and tow it will move up towards the M. If you can read EOT that is another good way to see temps as EOT typically stays pretty close to coolant temps if everything is working good.

 

[wildbill963258]

Well just an update it's the outer harness for those back 2 injectors

 

[Garbage_Mechanic]

Halfway through reading this thread I was ready to ask you if you had checked or replaced the plugs on the chassis side of the VC.
One thing that really helps glow plug harnesses last is updated programming that shuts off the glow plugs sooner when EOT is up. There used to be a kit with a water temp switch too but any modern tune will update it too.
(still on the originals on the 96 at least since 2002 when I got it)

 

[wildbill963258]

Halfway through reading this thread I was ready to ask you if you had checked or replaced the plugs on the chassis side of the VC.
One thing that really helps glow plug harnesses last is updated programming that shuts off the glow plugs sooner when EOT is up. There used to be a kit with a water temp switch too but any modern tune will update it too.
(still on the originals on the 96 at least since 2002 when I got it)

The front plug has been recently replaced on that side because when the original problem started that plug was trashed. But the back plug was still good at the time.

 

[wildbill963258]

Well replaced the back pigtail on the left bank and still has a miss after swapping out uvch's yesterday. So now I'm stumped. I haven't spent any money on these parts these were all left over from trying to fix it earlier this year. The gaskets and uvch's were bought used but only 10k miles on them and all look to be in good condition none of the connections crumbling or anything like that.

 

[wildbill963258]

I'm about to the point of just replacing the entire harness and VC gasket and ucvh's with all new parts or good known parts

 

[Calico5]

I'm about to the point of just replacing the entire harness and VC gasket and ucvh's with all new parts or good known parts

That's probably your best bet. Get Ford OEM UVCH/gaskets. Stealership, or from that "diesel_site" that sells diesel stuff on the interweb...

Also, consider: your temp gauge is reading engine coolant temp, but your UVCH is exposed to hot engine oil, which is usually a bit hotter than your coolant.

Lastly, the wiring in the UVC harness must be carefully and correctly routed and zip-tied together (as the factory ones are) to keep them from chaffing on the head, injectors,glowplugs, etc. It's worth the extra few bucks to get OEM.

 

[wildbill963258]

I have OEM on the problematic side that only has 10k miles on it with the exception of the engine harness (which is original to my truck and shows signs of being messed with) I can unplug the back pigtail on the problematic side and the engine will run fine just on 6 cylinders but if I plug the back pigtail back the IDM will shut that entire bank off and on. And when the IDM shuts that bank off it will of course throw the CEL

 

[79jasper]

That could be a injector solenoid as well.

Sent from my SAMSUNG-SM-G930A using Tapatalk

 

[wildbill963258]

How could I troubleshoot that?

 

[old man dave]

Unplug a solenoid, start engine and see if problem goes away. Just be aware there is 100 volts DC on the solenoid plug when the engine is running.

 

[wildbill963258]

Unplug a solenoid, start engine and see if problem goes away. Just be aware there is 100 volts DC on the solenoid plug when the engine is running.

So put tape around the end of the plug so it wont ground out?

 

[wildbill963258]

When all 8 injectors are plugged in the truck will idle just fine even free rev (rev the engine while in neutral) to almost redline just fine but the moment I shift into gear and release the clutch I can short shift to 3rd before it acts up.

 

[wildbill963258]

What should the resistance be for the injector solenoids?

 

[wildbill963258]

Does my battery light coming on have anything to do with my issues?

 

[Bugman]

Here is a test that you can run from the IDM harness at the IDM. The injectors should ohm out between 2.8 and 3.6 ohms.

 

[wildbill963258]

Ok so today I finally got around to fooling with my truck took the valve cover and gasket off swapped the harnesses around (the front went to the back and vise versa) hooked it up started the truck and took it for a small test drive (didnt leave the road that my gf's house is on and it's so small that even my little nitro rc truck can run up and down it without going out of radio range)to put a load on the motor and for now it's fixed even left tire marks on the road in front of my gf's house. Now I'm gonna put everything back together and later today when my son in law wakes up (he's down for a nap and her and her family are at work today) I'm gonna take it for a real test drive.