Since it sat up for a while what are the condition of the battery/cable terminals? Are they corroded?

 

Batteries were on a trickle charge the whole time and everything cleaned extensively with a wire brush before install. I know it's not related to the batteries or starter since voltage and cranking speed are top notch.

I also read that it could be related to injector o-rings. I guess if oil is leaking down that could prevent a quick start, though I would expect to see some blue smoke immediately after start while that gets burned away and I don't see that.

After it's warmed up and at idle, it does tend to get a bit rough. There is a distinct audible difference but I am not sure how to explain it.

 

I checked the HPOP oil level and it was not low. Seemed to be just a little below the bottom of the threads. For ****s, I left the plug loose and let the engine idle so some oil would trickle out and then tightened it as it was running. I don't know much about the HPOP or if there would have been a chance of some drainback or air entering the system, but after doing so and firing it back up, it still took longer than in the past, but no 8 - 10 seconds like it has been taking. It may get better as I drive it around more and get everything flowing again.

 

Okay if you have a scanner next thing I would check is RPM, ICP, IPR duty cycle and voltage. If the PCM doesn't see the numbers it needs it won't start or will take a while (long crank) until those numbers are achieved.

It could be injector o-rings but since you said the fuel bowl looks clean that eliminates the lower o-rings being the problem. You could still have the top o-rings leaking and to check that pull the valve covers off, start the truck and look to see if large amounts of oil is spitting out the top of the injector.

The scanner will be a faster way though just look for the IPR duty cycle to jump above 45% when cranking, in conjunction with a low ICP. Those two together usually mean a high pressure oil leak somewhere


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I will give that a shot. With the valve covers off, how long can the truck run for? I've not done this, but my only assumption is an oil mess waiting to happen.

 

You won't have to run it long maybe a minute or two. It should be quite obvious when the oil starts squirting.


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Finally getting around to doing these checks. I pulled the valve covers off and started it up and let it idle for a minute. I see small amounts of oil coming from behind the push rod areas, but it's all consistent across all injectors. Oil isn't shooting out. It's the oil amount that I would expect to be in the valve cover to keep everything lubricated.

I have an OBD2 Bluetooth scanner than on my phone shows more than just codes, but will read out some other values too if the system allows for it. I can see if I get ICP and IPR readings from that. If not, it may involve acquiring an advanced scanner to figure it out.

 

Jump the large posts on the GPR for at least 30 seconds prior to starting, does it start any quicker?

 

No change there. I have the upgraded GPR and all new glow plugs as of a couple years ago. This also occurs when the engine is up to temps too. In fact, starting the engine back up after it's been turned off and sitting for a little while (while still warm) takes equally long to crank and usually gives a rough idle, like it's missing, for the first couple seconds as well. My scanner isn't able to read any live data unfortunately, but it did give me a laundry list of other things I need to fix.

 

I also unplugged the ICP sensor with no change in cranking. I pulled it, cleaned it and reinstalled. No change. The sensor is also relatively new too. I had failure a number of years back with it. It's also the newer style with the big base to it.

 

I have my friend hopefully bringing a scanner from his shop over in the next couple days that should be able to read this live data so I can better pinpoint the issue. It doesn't make sense that it didn't used to do this prior to it sitting for a couple years.

 

My buddy brought his scanner over and this is what we found.

On a cold engine:
- cranking to start would take the IPR DC from a relatively low value (say 15%) and would reach 90% before starting.
- cranking to start would take the ICP reading from it's initial low value, then >500psi, and eventually close to 2000psi before starting.
- RPM at most ready 128 during cranking, but was typically around the 100rpm range.

Something is constantly draining the batteries. 2 weeks of not running and the truck won't turn over. I've tried to test current draw and I am getting nothing once the GEM shuts off.

My mechanic friend is thinking we check the starter current draw. The RPMs are lower than necessary (he read 150 was needed) and it could be drawing too much current, perhaps intermittent current draws which kills the batteries. I'm also going to take the batteries in tomorrow and have them both tested again.

HPOP is full of fresh oil. Fresh fuel. No leaking injector o-rings.

 

The IPR % calculations you have there (15-90%), are you calculating that percentage from voltage yourself? It kinda sounds like that and that's Not what the percentage number pulled from scans mean (all my scanners use percentage and I know some talk about voltage so I'm not really sure what that means)

The IPR is controlled digitally, it's not an analog variance with voltage. It's ON or Off and the percentage of OFF during the cycle is what the percentage reading scanners give is derived from.

So, if you ever see 90% that's telling you the IPR is struggling So Hard to maintain pressure that it's Closed (that's the bleed is closed) pretty much all the time. If you are reading a percentage, and not calculating it from voltage yourself, you have big HiPres Oil problems...

Again, I'm not sure How you're supposed to use a voltage reading because I never see that But I understand how the IPR works and it doesn't make sense to me that you can say voltage is low-to-high and the percentage of 12v is the duty cycle (could be wrong here, somebody who knows IPR voltage readings as related to percentage could tell us both more)...

 

The reading shouldn't have been based off of voltage. There may have been an IPR voltage log to the reader, but we didn't focus on that. The focus was reading the duty cycle %.

Assuming it is a HPOP issue, which I doubt it is, how would this go bad for just sitting? I suppose it could be a valve elsewhere letting the oil bleed back (bad IPR?).

 

So it's tricky. First because what you read as the duty cycle % isn't necessarily what the IPR is actually doing but rather what the PCM is commanding it to do. So, the IPR could be stuck open, bleeding-off all the pressure the HPOP can make and those IPR readings don't mean anything.

You know you can take it apart and clean it (I like freebee tests). Maybe that would be the next step...

 

I still have a feeling my issue is electrical-related, though I am not ruling out that the IPR doesn't need cleaned as you mentioned.

I took both batteries into Auto Zone today to have them tested. Both tested bad. This is the second set of batteries I have installed on this truck. Something keeps killing these damn things. With the new ones installed, it cranked and started. Though not immediately, it seemed quicker than normal. With all the body/chassis codes listed on page 1, something there has to be toast that is causing all these faults. Not sure if it is the GEM or what.

I am going to move focus away from the oil system for now and focus on what is causing all these codes before I kill another $300 in batteries.

 

After doing some voltage testing in the interior fuse panel, I came across something strange with Fuse 20 (15A) which is labeled as Starter Motor Relay Coil, PCM (Gasoline only). On this fuse, with the key off, I am getting ~5.4V. The rest of the fuses are either getting 12V or 0 depending on the key position. Fuse 20 is also tied to the GEM as seen in the attached diagram. My guess is that since I am getting an odd voltage with no key on, there is something wrong with the GEM causing it to provide partial voltage at all times, or a wiring issue. I removed the fuse box and GEM earlier and took it apart. There are no signs of corrosion at all. And nothing that stood out on the board of the GEM itself.

Anyone else able to do a voltage reading for me on Fuse 20 to see if you are getting anything different?

 

Upon further checking, I pulled the 4x4 switch to measure the VREF wire where I expected ~5V from that, but was only getting about .04V with the key on. I am leaning toward a bad GEM.

 

It may turn-out that you have in fact have a GEM issue, but,,, what would that have to do with your Long Crank?

The GEM is the Body Control Computer, the Powertrain Control Module controls everything for starting...

 

Long crank could have very well been related to my 2 batteries that were toast which was causing low cranking RPM which would also relate to taking longer to build the necessary pressure to fire the injectors. With the brand new ones, it started up much faster.

 

OhKayyy,,, and the GEM?

 

Not sure exactly what your question is

 

I thought we were talking about the GEM and you thinking you had discovered the source of your problem as being GEM related.

I said I didn't see how a GEM could effect starting.

You said bad batteries caused slow cranking.

I was asking about what happened to the GEM~vs~Starting discussion...

 

Sorry, kind of lumped 2 topics into the 1 here. GEM is throwing all sorts of codes, and with my checking of different voltages that don't appear to be consistent, and the fact that something is constantly killing the batteries is why I mentioned the possibility of the GEM being bad.

So the long cranking is on hold for now (even though it's much better) since that's only a minor issue compared to the electrical problems going on.

AE scan tool should be here in a few days and that will allow me to see more than I currently am.

 

I was reading this because I have been having the long crank issue on and off for a few months. Both times I took it out and blew the snot out of it and started cranking almost instantly. The last time it did also but has come much faster than before. Look forward to end result here.

 

Well, both of my batteries were testing as bad so I bought 2 new batteries. They were not that old either, maybe a 3 years at most and the truck has been sitting for 2 while I do repairs. I would leave the batteries connected initially while I had to move it around occasionally, but once it got to the point where I was doing all the frame repair and clutch replacement, the batteries were either disconnected or brought inside on a charger.

I think I found out what was causing them to go bad though. My 4x4 has been intermittent for a while, and more recently didn't work at all. I put down the money for an AE scan tool because the standard OBD2 one wasn't telling me enough. I noticed I was getting codes about short to ground on the transfer case motor and other misc electrical error, including open circuits to both clockwise and counter-clockwise 4x4 relays. After investing hours and $1k in new hardware, turns out there was a pinched wire in the harness under the hood that was causing my open circuit for the 4x4 relays and likely the same short to ground issue I was seeing. I am no longer getting those errors after fixing the wire, replacing the transfer case motor with a new one, and other wasted components.

It's still cold so start-up isn't instant, but much better than it was. Fingers crossed the new batteries are the answer.