I haven't been on here in a long time, but here is my issue.
Truck has an intermittent miss that has only showed up while it's been raining and the truck has sat all weekend long. I was thinking it was moisture getting into the IDM, but while I was checking out the connections going into the VC I found a bare wire on the DS, I think this one is for the GP's.




My question is would this cause the DS injectors to go dead?

 

Your #8 GP wire is burned up, and there are fusible links that feed the GP relay. You will need to find the root cause of the burn, and there are two likely causes:

1. Your GP wire under the VC, or the GP itself has shorted out (not as likely).
2. You have a bad connection somewhere between the battery and the GP (very likely).

The bad connection can be tired contacts on the GPR, a bad UVCH, fried/loose contacts at any connection point in the circuit, or a "noisy" command for the GPR to activate. UVCH is highest on the list, but the whole system has been compromised now and everything GP-related should be inspected and ohmed out. The four outer-most wires on that connector in the photo are the glow plug 12V supply from the relay - one pair in the rear is for 6 & 8, and the pair in the front are for 2 & 4.

 

I did my GP's a few years back and updated the UVCH, so I'm hoping it's not that. When I ohm it what values should I be looking for and where should I start in the system?
Thanks for the quick reply

 

Does it happen when you're driving down the road or at idle too? Is it like a split second hiccup? Are the wipers on when this happens?

Stewart

 

Crud... I forgot, but somebody here has the number. I just say they should all be very close to the same (in reference to the engine block).

 

I has happened twice after two consecutive weekends of rain, a few minutes after I start the truck it runs on the passenger bank (EGT's go down), I shut down restart, runs good and it may or may not do it again. It seemed to go away after it's warmed up (this happeneds with or without the wipers on). But today it did it while driving and the truck died. The truck dieing may be another issue with my F5 controller, it will randomly lose it's connection and the truck will die, I wiggle it and it turns back on and I can restart the truck, that's happened a few times over a couple years. I went as far to zip tie the controller to plug on the back if it.

 

So it's not actually a miss then, you're actually only running on 4 cylinders? You have a whole bank that doesn't run?

Stewart

 

Rich, (or anyone who knows how to do it) give me a quick lesson on how to ohm these? I've done some searches, but haven't came up with much. I have a nice multimeter to use.

 

sniff... sniff... There's Eau de UVCH in the air. First, it's safest to pull the chip and run stock when things get weird... to simplify the list of suspects. I don't suspect the chip or its connector, but I've seen cascade failures confuse matters.

When you "updated the UVCH", was it a replacement or the 50-cent mod?



Did you thoroughly inspect the pins on the VC gasket, or just do the UVCH?



To test the whole circuit to the solenoids, you can conduct a resistance test from the 42-pin connector over the DS VC.

 

It was a replacement UVCH from Ford

I don't remember seeing anything suspect, it was 3.5-4 years ago.

Here is where I not sure about what I'm doing. How do I go about doing a resistance test? Do the P+ and D+ stand for passenger side and driver side?

 

That's what I am assuming, because when it happens the truck runs rough and has no power and I loose EGT's (gauge is on the DS).

 

I've got the 42 pin connector apart, and I need a little help. Pins all look good, but I have no idea how to test for resistance.

 

I don't have a pin out handy, but I'm guessing P+ stands for passenger common. That would mean place one lead of the ohm meter on P+ and the other against 1, 3, 5 & 7 to test the passenger side. Then test D and 2, 4, 6, 8 the same way. A reading of less than 5 ohms should be what you're looking for (at least it is when testing at the valve cover. I don't know if the additional harness length will affect that any).

If it only does it when it rains, I'd be more suspect of other issues, but since you've come this far, ohm this out and see what you get.

 

Hold one probe to D+ at all times (Driver-side power to solenoids). Take the other probe and check the ohms to each of the even-numbered injectors. Repeat this step with P+ and all odd-numbered injectors. You should get your answer right quick.

Any crud in there? Use electrical contact cleaner spray and a toothbrush, then dab some dielectric grease to keep things sealed in there.

 

Looks nice and clean, I'm not getting any reading I don't think I have my meter set up right.