He did - a few times - this time and 2 weeks earlier. At idle, it failed the 1, 2, & 8 cylinders. But, bring the RPMs up and everything passes. When they worked on it two weeks ago, everything passed at all ranges. That's why I'm leery of the diagnosis. Three injectors within this time span without a lick of warning?

When I drove it home today, I connected the ICP and tried to start it. It fired and died once and then just cranked. Hooked up the ICP and it fires right up. I played with the outside connections at the VC's and checked any wires I might have come in contact with while I was changing the IPR. Nothing changed. I'll be able to get more in depth this Saturday.

 

What is your CPS status?

 

The shop switched it with my spare with no change. I believe they switched it back. That one was switched out just last month.

 

Does it start up fine cold? How does it start when it's warm?

 

I'm not sure yet. Just got it back last night and I drove it without the ICP. So, it was warm when I got home. Didn't want to play with it at 4:00 this morning. I'll check when I get home. The shop says it'll start cold but when it warms up the oil pressure drops to 470 and it won't start. I'm not sure if it's actual pressure or what the ICP is saying.

 

How many miles do you have on it?

What kind of oil is in it?

Does it have the original injectors in it? Injector o-rings?

Thin oil, along with o-rings that have some age, mainly o-rings with some age, will cause the problems you are having.

 

I suppose it's possible that I got 2 faulty ICP sensors, but not probable. I'm also looking at the IDM - will see if we can swap my buddy's into mine to rule that out. The IPR is new from Riffraff, so it has to be good . The shop said it was at 14% - not sure if that was cranking or running, hot or cold, or what. Wouldn't I have some indication that 3 injectors were going south? Or is thisthe indication?

 

First of all, I shouldn't be posting in this thread, because I really know nothing about all the sensors you guys are discussing. So, sorry in advance. But, what was the mechanic trying to "blow out" by putting "tranny fluid" in the fuel bowl?

I have plugged injector holes. I looked at them under a stereoscope. The seven holes in each injector nozzle are really, really small and not all of mine looked the same, some, in fact, looked plugged. Assuming that I do have plugged injectors (from my absolutely positively confirmed delaminating steel fuel tank) they are hopefully causing my copious amounts of white smoke (I hope by dripping rather atomizing diesel fuel in the cylinders).

You say you don't have smoke. You have a starting and running problem. My 7.3 has no problem starting right up. It just smokes white/blue smelly diesel smoke. Yours does not smoke. So, I doubt your injectors are plugged like mine.

Phinner recently posted that his PCM was flashed in 2008. Is it possible that Phinner is running stock injectors with an aftermarket flash? Or conversely, is it possible that Phinner has modified injectors which he is running without the appropriate tunes/tuner/programmer or chip? Are any tell-tale signs on the PCM or elsewhere to know if tunes/tuner/programmer or chip were previously installed?

Would AE tell him the answer to those questions?

I apologize in advance for speaking up here if I am way out in left field.

 

No apologies needed, Tim. This is my first diesel and I'm finding I need to learn things real quickly. So, any idea is helpful.

 

Hey, Tim, I just realized you posted about the hutch mod on another thread of mine. I'm going to have to get that done soon. But, I need to get this thing running first.

 

Alright, I came home and found out a couple of things (not sure if they mean anything, though). I plugged the ICP back in and tried to start it. First time it fired and died. I thought maybe if I give it some juice as it fires I can get it going. So, I tried starting it again and hit the pedal as soon as it started. It fired up, but sat wouldn't go above 1000 RPM. I let off the pedal and it started acting normal. It ran fine, so I let it sit there and run. Once it warmed up it starting the loping idle. Here's a video:


In the driver's seat, I can raise the RPM's and it smooths out. Letting off on the pedal, it drops down and starts loping again. But when I shift it into drive or reverse, the RPM go up slightly and it smooths out for a bit. Eventually, it drops back to a loping idle but not as bad as in park or neutral. It started every time I tried it, though. Here's from the driver's seat:


Oil level is good and the HPOP reserve is, maybe, 1/4" from the top. All other fluids look good.

Question: If it's the wrong type of oil, wouldn't I have noticed it earlier. We've put about 800 miles on it since we got it. I have been questioned about how clean the oil stays. Everyone says theirs turns dark soon after an oil change. Sorry, I don't have better specs - the scanner is coming on Saturday.

 

I didn't hear or see anything abnormal. A lope will generally be several 100 RPMs at a time. Shifting from park or neutral to a gear with the transmission engaged will cause ramps to increase slightly. Honestly, those two videos sounded like a health 7.3.

But I'm watching on my phone so audio is poor. But I saw no fluctuations in the tach.
You can enable a digital tach by turning the truck on while holding the ODO reset button. It will flash TEST the GAUGE and do a full gauge sweep. Press the ODO until you get to the tachometer. It will read T, TAC, or TACH. Can't remember. Once you are on the tac, go ahead and start the motor. See how much the idle fluctuates. I think it should be around 700

 

I looked it up. It will display "tAC"

 

I've checked out the little test feature, thanks to one of your videos. It is hard to tell how rough the idle really is with those videos, but it sounds terrible - almost like it's going to quit on you. It's nothing like it was the last 2 weeks. Here's the idle with the digital tach:


You can see how the RPM's are all over the place in park or neutral. Reverse and drive it smooths out and is relatively OK. It does get a little rougher as it sits in either of the gears, but not like park or neutral.

 

I'm on my computer now. I can hear what you are talking about a bit now. But it still sounds slight. I'm sure its just more obvious in person. As far as your tach goes, in my video my RPM spread is 20-30 while yours is about 50-60. Not a lot but definitely more unstable.

So I have been thinking about this at work today, and I really, really dont think its your injectors. I think its a sensor somewhere. Its just too strange that unplugging the ICP fixes the problem.

I started a thread regarding the +5v reference signal. Check it out here and trace the pin back. If I were you I would start looking at a lot of wiring. Check PCM connections, check for burnt pins, especially in the 42-Pin connector, look at the ICP pig tail, and trace it back.

It HAS to be something like that. You know what would be interesting... If you could unplug the ICP sensor (this would be an OPEN circuit) and then apply resistance. If the truck mimics the symptoms you know its not the sensor itself and its something upstream. I just cant get past that. It HAS to be something related to the ICP...