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Well I'm at it again and a little confused and lost. Here is a little back story. Replaced injector cups and valve cover harnesses then had coolant in my oil. Found out through here I needed to pressure test coolant system to verify cups were seated correctly. Found out cups in #5 and #7 were leaking by, so replaced them again and tested. Then someone suggested my oil cooler might be leaking so replaced o-rings and fixed coolant in the oil issue. Was still getting a P1316 code so totally rebuilt injectors and shimmed ones that needed it. Cup in #4 came out with injector so replaced. Got FORScan to buzz test injectors and all seemed OK. Just drove 300+ miles, guess what? Fuel usage sucks and P1316 is back. Attached are photos the two codes after buzz test. Any ideas on how to correct and how to figure out why I'm using more Diesel than normal?
Looks like you have a bad wire somewhere between the IDM and #4, the IDM pin point test in the tech section should confirm it. If it tests good then likely the IDM is to blame. As for the loss in mpg, my guess would be your motor is down an injector so it's trying to do the job of a v8 with only 7.
Not to sound dumb, but how do you do the test? Is it within FORScan or another way. I have a BAD vibration from 50mph and up. Steadied out at round 70mph but is still there. Plus shifts hard. Almost goes over 3500rpm when shifting into last gear or when overdrive kicks in. Both harnesses are new, but now days new doesn't always work.
The vibration could be related but I would recommend an inspection of all your front steering and suspension especially the ball joints and hub assy's. Bad u-joints and/or slip yoke can cause vibrations also. If none of those turn up any suspects then could have a tire out of balance, possibly a bubble, or tread could be separating. Could just need an alignment.
Already checked all of those and had an alignment not to long ago. Have rotated tires to see if that was the issue. When I let off the go go pedal the vibration stops.
Thank you, I definitely appreciate the assistance. Shame didn't have someone who lived close by. LOL
Sometimes we just gotta learn to be "the someone". Break it all down and it's just hunks of iron held together with nuts and bolt, zig-zaged with wires and doused in motor oil and diesel fuel. Simple right?
Already checked all of those and had an alignment not to long ago. Have rotated tires to see if that was the issue. When I let off the go go pedal the vibration stops.
That does sound related then. Odd that it's speed specific though.
This and loads of other info about these motors and trucks are in the Tech Section at the top of this forum in the sticky's.
So looking at the link that you shared, I have to find my IDM to be able to do this test? From what I've been able to find on Google, it is supposedly located up behind my driver side wheel well? That is a stupid place to place it. Is there another way to test without doing the Easter Egg hunt?
You could try checking from the 42 pin at the valve cover but if the problem is between the IDM and the 42 pin you won't see it with the meter. If you do try that first inspect the 42 pin where it rubs the valve cover at least to rule it out. Here is the 42 pin map if you try that first.
To rule out a short to ground you can also check each supply and each injector to ground, you want to see OL in that test, if I'm not getting confused. I believe the ground is supplied by IDM which triggers it to fire, not 100% on that bit though.
Awesome, thanks a lot. I can turn wrenches all day and weld stuff together. But electrical stuff on vehicles I'm a little clueless I do appreciate the assistance. I'll give an update once I'm able to test it. 🙂
