Those resistances all look good. If it's a wiring problem, it's either elsewhere or it's intermittent.

Where do I look next? ICP and pig tail was replaced a week ago along with a new fuel filter

since I don't believe this to be the 50 cent mod I have created a new thread https://www.ford-trucks.com/forums/1...l#post14275104

Hey guys! Not sure if I'm posting a new thread or not. Anyway, I have the symptoms of a loose injector harness. The only difference, and I've not seen anyone mention, is my rough running engine happens intermittently. It sometimes does it on start-up, sometimes at 70 mph on the highway, sometimes just sitting at a stop light. Could happen anytime. Other times it runs just fine. It started doing this mid to late last fall and when winter finally did set in, I never had a problem at all. Well, now that spring is here and warmer temps, it's acting up again. Also, turning the ignition off and restarting sometimes "fixes" the problem temporarily. Is there somewhere else I should be looking other than the injector harness? Very weird! Thanks in advance for your help!!

It's a pretty cheap fix if it is the harness, I did it with help from a friend. You should take it apart and fix it yourself also. Mine did that as well with it not being able to start at times or randomly stalling.

hello
 

Hello can someone take a measurement from the end of the plug that loosens up to the valve cover gasket thanks

Black smoke due to loose UVCH?
 

Hi all, I'm a new poster here, though have gleaned some good information here in the past 7 years running a 7.3L. Our 2002 F350 7.3L with a bit over 200k miles on it has random SES/CEL light that comes on with severe misfire and code P1316, major loss of power, and black smoke with throttle. EGTs drop drastically when this happens (200 or less at idle, maybe 400 if started at 800 going up a hill before misfire started). This may happen while sitting idling after startup, while into the throttle going up a hill, or when idling hot after running a while--anytime hot or cold. It comes and goes, but normally doesn't go unless idling (will keep misfiring if above idle). It may even have a mild misfire when SES/CEL light is not on, but is not obvious (just seems like idle has a slight rough spot in it now and then). When CEL/SES light is on, the power loss ranges from major to extreme; with steady throttle on level grade there are noticeable changes in the amount of power while misfiring. Under throttle with CEL/SES light, there is always black smoke, more with more throttle.

I've read the thread. Thank you all for all the great info. I haven't noticed anyone else mentioning black smoke, but maybe I missed it. Could the loose UVCH issue result in black smoke along with the shaking loss of power (seems like running on well under 8 cylinders) that can come and go while the truck sits idling?

When the CEL/SES light is off, the truck has good power and seems to run normally--except for the possibility of an occasional minor miss on idle (slight shake).

As background, I had similar issues before recent replacement of all injectors (were original at over 200k miles and had seemed lower on power and hard to start without plugging in even mildly below freezing for some time) and the injector wiring harness (done by a diesel shop for plenty of $$$$). The major difference is that before the injector replacement, there was no smoke regardless of how much throttle when the CEL/SES light was on for P1316 and truck was shaking with barely enough power to move in a parking lot. Now there's plenty of black smoke with throttle...

The new injectors are single shots which required a tuner (PHP Hydra). I've confirmed the issue happens regardless of which tune the truck is running, hot or cold, idling, or working hard. When it happens, so far turning the truck off and restarting always results in it running relatively normally again for anywhere from 5-10s to several minutes. I might be good for the first 10min of a drive--though not always; it may happen while idling for a few moments after startup--but once it starts happening, it usually recurs quickly even if it goes away on restart (which it so far always does).

I'm thinking I need to check the UVCH's even though they're new (less than 2000 miles on them and injectors), and check connections all the way from IDM to there as well.

We recently had the apparently original alternator fail suddenly (burnt insulation) and replaced with a DC Power 270 XP along with upgraded 1/0 ground from mounting bolt to frame and 1/0 charging cable from alternator to battery. I doubt this is relevant, but thought I'd throw it in just in case. The problem most recently starting occuring while limping home with dead alternator (45min drive in boonies--worst voltage seen while running without alternator 11.5V). Alternator replaced and good voltage now, but the problem is still there. However, the problem did occur just once immediately after the injector job about 10min from the shop driving freeway speed on the freeway. It went away with 30s of idling on the side of the road and did not occur again for the 1000 mile drive home or short trips near home since then till alternator failure. To add another variable into the mix, that drive home was with a couple standard single-shot injector tunes the shop threw on as PHP hadn't got the custom tunes out yet. Those tunes did not run as smoothly and produced some soot flakes from tailpipe at idle. Received and installed PHP tunes (and ditched the temp ones) some time before the misfire/P1316/CEL issue recurred recently.

We like the truck and plan to keep it for a good while yet, and are hoping this is our last significant reliability issue after new heavy duty rebuild on tranny and larger tranny cooler (was original and showed some beginnings of bad wear inside on inspection after some random overheating episodes--first one under GCVW 25,000 lbs up a steep highway at around 0 deg C and last one empty truck at -40 deg C) and injectors in last two years. We live in a very remote location with no shop or parts store nearby (pretty well anything is a 10hr drive away).

I am curious if the black smoke under throttle along with low EGTs is normal for the UVCH issue, or if there's something else I should be looking at. Please let me know if you have any further ideas/cautions/suggestions based on symptoms and history noted.

And please let me know if you have any other questions. I do not have AutoEnginuity, but plan to buy it. SCT device just gives P1316, nothing else.

If there's a P1316, it means the IDM has codes stored. In order to access those, you need a scan tool capable of running a KOEO or injector buzz test. The lower EGTs would correspond to the reduced amount of fuel burned, caused by cylinders that aren't firing.

Thanks Pikachu. That all makes sense. I've convinced myself I need to order AutoEnginuity Monday, and hopefully get it within a week to to KOEO and buzz tests (no shop around here than can do this).

I'm still puzzled over the black smoke during P1316/CEL/misfire, and whether that fits with a loose UVCH and wondering if it is something else. It seems like this would be timing related rather than less/no injection on some cylinders (and UVCH is new), but all the other symptoms seem to fit what others have posted and resolved with UVCH fix. :confused: Anyone else with the UVCH issue have black smoke with throttle during misfire episodes, or am I headed down the wrong road with UVCH?

Black smoke, at least in my mind, would make sense. The cylinders that are firing are probably getting too much fuel for the reduced boost level and not completely burning it.

The lower EGT's actually tells you where your problem is. If your pyro probe is in the driver side up pipe, then your driver side UVCH connector is suspect. The reason the EGT's are so low is because some of your cylinders in the bank with the probe are not firing.

Of course they could also drop if the other side stops firing since you're not really putting enough fuel through there to get the truck moving well.

The last time I saw a whole bank go out, it was the passenger side (on another truck). The driver side (with the pyro) got hotter-n-hell just driving around town. The next time the truck misbehaves, bear in mind the side without the probe is getting real hot.

Thanks all. Yes, EGT probe is on driver's side up-pipe. Good point about the other side... every time something acts up I need another gauge... EGT per side. Don't expect that'll get enough use to be worth it though :)

So no one else noticed black smoke when into the throttle with misfire due to UVCH issues. I may try ohming things out Sunday, though with the issue being so intermittent (and disappearing for at least a bit every time the engine is stopped/restarted) I'm not sure if that will show anything. I may just have to pull the driver's side valve cover and inspect the recent work done in there--and I'll leave the dog house in place thanks to an earlier poster's tip and the fact the closest parts are several days shipping away. There's nothing obvious wrong with the harness on top the engine on the outside, though I'd have to pull apart the loom and tape to be sure.

I have a Swamps 140V high frequency IDM on the way just in case (takes a while to get anything up here and second vehicle is an ATV...), but want to make sure there isn't anything wrong with wiring that could wreck a new IDM if the old one is indeed dying.

Nice avatar Rich :) Gave me a good chuckle. We've spent more on the truck in the last two years than we paid for it (used). But to be fair, there weren't any significant expenses (besides fluid changes, etc) for several years of good driving before that. At this point, I'd like to see it run till up somewhere closer to the miles Chris has; have spent way too much on it to sell/trade it, and we like the truck.

check to make sure your injector plugs are in tack if so then one is more than likely clogged
 

mine did same thing was ready to bang head aginst wall but come to find out finally that injector was not plugged in correctly it had loose connection! hope this helps

Hello can someone take a measurement from the end of the plug that loosens up to the valve cover gasket thanks