Went two miles downtown to get some diesel. Leaving the station the motor started shaking bad, like it was running on one bank. Went two miles up hill to home with my foot on the floor. I noticed my driver side EGT gauge (yes, I have two EGT gauges) was at about 200* and my passenger side EGT gauge was maxed out! That told me the driver's side bank wasn't working, so I thought. Today read the codes and they were p0562 & p0603, WHAT?? I have good batteries and the alternator was putting out 14+ volts. A couple years ago put in a new battery harness and the terminals were cleaned lately. Anyway, pulled the drivers side UVCH plug (SD upgraded) and motor quit which surprised me thinking that bank wasn't working anyway. Cleaned it up with electronic cleaner and did the same on the passenger side. All the pins looked OK, none burned or anything. Fired it up again and still ran like total crap. Started checking again for codes with my A&E and it stopped running rough and smoothed out. Took it for a ride and beat on it hard and it ran great. My question, do you guys think I should pull both valve covers and replace the UVCH's just to be safe and keep me off the side of the road this summer?? I had good fuel pressure thru all this and no leaks that I can see. Just changed the oil and fuel filters and few hundred miles ago. I'm stumped, thanks in advance for opinions. Sorry, haven't posted much lately and here I am asking for help, me bad! Thanks in advance!

 

Engine harness is known to fray and driver VC, UVCH or IDM

Ohm out everything and check the loom

pin out for ohming
https://www.ford-trucks.com/forums/1...load-test.html

 

Thanks for the reply Knotty and the link!

I tried a few things so far because it started running terrible again. Pulled my chip and put in my spare IDM, no good results. Maybe I should try my spare computer too? I ohmed the injectors, all were 3.1 or so. Cleaned the UVCH plugs, no good. Did a buzz test and came up with p0196 (EOT sensor range), p0267 (injector #3 current low) and p1298 (IDM failure). Year before last I ran the truck 500 miles pulling my heavy 5er with one injector out, ran rough but nothing like it is now. Doesn't even have enough guts to pull up onto ramps. I used a infrared thermometer gun and while it was running checked the heat on the exhaust manifolds, drivers side was 250* or so and passenger side was around half of that. This was the opposite of what I observed while driving home, the drivers side was a lot cooler then the passenger side. I don't know what that means??

Its terribly windy down here (hot too) so I don't want to pull the VC's off just yet. When I do I'll replace the wiring harness's and fire it up. If it still runs like crap I'll think about ohming out everything. Then maybe sending Jim Rosewood the injectors to check out, there really isn't that many miles on them. When my foot is on the floor there isn't any excess smoke, white or black which seems strange to me. New fuel filters on it also and a steady 65psi fuel pressure.

 

Engine haness short or possible the PCM if it thinks the IDM is bad.
The enging oil temp is odd with this. leading me to a wire in harness

 

I think I would ohm out the harness through the IDM connector. It would be a good way to verify the integrity of the harness. It is odd that the temps have swapped sides. Is it hard to get it started?

 

In that case I'll ohm out the harness BEFORE I try the spare PCM.

Very hard to start Ben, then its like its running only on a couple cylinders. I ordered a new CPS from Riffraft for the heck of it.

 

Assuming I did this right, (big assumption) my guess its only running on two cylinders might be right, #4 & #5. #1 ohmed at 7.8, #2 19.1. #3 7.4, #4 3.1, #5 3.0, #6 19.2, #7 11.3, and #8 19.2.

For the drivers side I held one probe on 23 and checked 22, 7, 19 and 9 for ohms. On the passenger side I held the one probe on 24 and checked 6, 21, 8 and 20 for ohms. Is that the correct way to do it? I didn't have the key on and the UVCH plugs were plugged into the VC's.

I unplugged both UVCH plugs and at the plugs to the IDM connector I checked all individual wires and they all had continuity. So, can I assume the hardness is OK? BUT, why could the ohm readings be so far off, are my injectors screwed? There isn't that many miles on them, maybe 60K or 70K? Also its confusing why it ran like crap, then cleared up to run great then the next day runs like crap again??

I appreciate your help!!

 

Just wanted to add that in post #3 above I stated that I ohmed the injectors all at about 3.1 or so. That was done on the VC and it was very hard to get at. When I ordered a new CPS from Riffraff I also ordered a pigtail and when it comes next Monday or so I'll do that test again using the pigtail. I just don't see how accurate that first attempt at ohming the injectors could be after ohming today thru the IDM connector plug and getting ohm reading all over the place??

 

4 and 5 seem to be shorted

I would peel back the loom over the Drivers side VC area and check for chaffed wires

 

I'll check it out, thanks man! I just don't know why those numbers are all over the place. I was also looking at buying a new harness?!

 

i wonder if you have contaminated fuel?

 

I dont think so, one bank wasnt heating up

 

Anything is possible Tom, when I was at the gas station I didn't fill up the truck, just got some gas in a jerry can. For my truck and two diesel VW Beetle's I get fuel at the same gas station Maverik. The two bugs are running well, we take them to Vegas all the time.

I pulled the wiring harness off the VC by unplugging it at the connector by the power distribution box and inspected all the wires. None are chaffed or broken that I can see. Pulled on them a little and the insulation didn't stretch anywhere that I could see or feel. I unwrapped the section that has the foil and bare wire wrapped around it and they all looked good to me. Maybe I should get a new engine wiring harness? IDK what to do now!

 

ohm out the 42 pin side again with the injectors unplugged
They should all be open, if they show any ohms under 1000, you have a short in the harness

 

Sure you don't want to swap the spare idm in and see before All that work? I can't say for sure but at the low miles that truck has I just can't believe it's a harness issue