M1088 camper conversion

[ckouba]

Tying all my recent experiences together on the build thread...

We went to UT & AZ for a lovely trip:

Road Trip - OR to UT/AZ and back

I have one or two things to wrap up, but if all goes as expected, we will be heading out in our rig on Weds to southern UT/northern AZ for a week in the wilds. After a handful of shakedowns, this will be our first real trip. Our route will be I-84 through Baker City, Boise, etc... to I-15 and...

www.steelsoldiers.com

We had an issue:

HEUI Troubleshooting - Injection Pressure Desired and Actual Mismatch

Anyone have any experience with this? I have a 2000 M1088A1. The CEL light came on the other day and with CAT ET hooked up, it showed code 164-11 and/or 164-2. Looking them up reveals a somewhat generic trigger of mismatch between desired and actual injection activation pressure on the HEUI...

www.steelsoldiers.com

With a little OTR troubleshooting (basically, an oil change), we packed up and drove home without issue. Happily, with a bit of logical troubleshooting and an Injection Actuation Pressure Control Valve replacement (CAT p/n 122-5053), the motor is now back to 100%. Thankfully, with the 3126, the control valve is external to the HEUI pump and a very straightforward swap. It's internal on the C7 and may not be individually replaceable based on what I saw on the internet.

That issue aside, the truck still ran fantastically. We have another trip planned in April/May and I am looking forward to getting it on the road again. The area is magical!

 

[ckouba]

Two quick updates...

As promised, when we returned, I ripped apart the bathroom to get it set up more appropriately as a wet bath. The current toilet came out, a shower sump was installed, a raised floor with drain and plumbing built, and a new toilet enclosure started. I was working on getting the walls built out but got distracted. By what, you ask?

I started the motor on Fri just because... and it ran like crap. You can re-visit the thread in the LMTV forum (see link at top of prior post) for details, but the desired and actual injection actuation pressures do not match so there's a problem with the HEUI system. Trying to get a conclusive assessment of it, but it may require a new pump and a bunch of additional filtration hardware. Stay tuned to the other thread to see what develops on that issue.

In the meantime, I will start acquiring parts while pushing on with the shower. Goal is to have it back together for the trip at the end of April.

 

[ckouba]

Began a thorough investigation yesterday which effectively ended up with open heart exploratory surgery.

I started the day with checking the harness/connectors to the IAPCV (Injection Actuation Pressure Control Valve- the thing which controls the oil pressure sent to, and used by the injectors to fire fuel into the cylinders). I actually pulled off the intercooler to manifold pipe to make this easier. After that, the task was incredibly easy. There are only about 2 feet of wiring and it appears that it comes directly from the ECU without any intermediate connectors.

There was talk of a degraded block to HEUI pump oil line. Not the case here. It was a steel pipe already and looked in good enough shape.

Rick showed up with his scope around this point, and we started with scoping the signal going to the IAPCV. The first trace we got was with the ignition on but not running. Looked like this:

It's a little tough to read on the screen, but it's showing about 9% duty cycle with a wider pulse followed by 3 or 4 narrow pulses. Over time, the signal was consistent and didn't seem to vary when poking at or jiggling the wires.

Next up we started it and kept the scope running at idle, which looked like this:

For starters, it ran like crap- indicating the problem hasn't miraculously cured itself. It never fully warmed up but after a few minutes of running it was a little bit smoother. Running at idle had it at ~13% duty cycle with the extra spikes on the scope trace. The pattern was quite consistent though, so despite our mutual lack of knowing what the trace should look like and the fact it wasn't changing as we knocked around the wires, we were comfortable enough to say it was running correctly and moved on.

As it was already running, next order of business was to pull the valve cover. This was fairly uneventful, with consistent streams out of each injector. We did a cutout test with each injector, shutting each one down individually and observing the results. In each case, the motor roughed up when we shut one off and smoothed back out when we turned it back on.

Since it was running, one of the suggestions was to pull the plug off the IAPCV, which we did. The motor promptly died, so I guess it passed that test?

At that point we were about out of test procedures and all signs were pointing to HEUI pump. To get a thorough understanding of what may be going on with the whole system, we pulled and cut the filter to see if there were any shimmering warning signs in it. Cutting to the chase, no, there weren't. Everything looked dark and smooth and basically devoid of shiny flakes or particulates.

As we were already pretty deep into this and I really want it bulletproof on the other side of this work, we also pulled out the oil cooler to check it for flatness. There have been occurrences where the gasket in the cooler fails internally and allows dirty oil to cross into the clean side of the filter, without any external sign of a leak. It didn't appear to have an issue (gasket-wise), but putting the cooler on the bench with a straight edge, it is clearly not flat and will need some surfacing work. Will be a hassle but don't want to have to go back in there- especially if there's no external signal for an issue. This was about the end of a productive day (with many thanks to Rick) so I stepped away for the evening.

The cooler warpage (I think lens optics make it look worse than it really is, but it definitely needs some attention):

Seeing as the HEUI pump was still looking like the guilty party, I worked through the steps of its removal this morning. It wasn't too bad since all the crap was off the motor, and it's now resting on a crate with the turbo, oil cooler, and other large parts.

Next steps will be extensive- I have the IFS filter kit on order (HEUI pump to head), an oil bypass kit as well, I want to figure out if the C7 block-to-HEUI pump filter line is adaptable to the 3126, and then I have a whole bunch of crap to replace and reinstall. Good news is the turbo looks good and its bearings spin nicely.

I also pulled the compressor head while removing the HEUI pump, and that will go off for a rebuild while I am assembling other parts.

Basically, I've got a massive boat anchor in the carport at this point. I look forward to getting some parts and putting it back together.

Port:

Starboard:

 

[ckouba]

Progress has been glacially slow, but at this point I have replaced the oil pump with the updated one and closed up the bottom of the motor. Oil cooler (freshly decked, had 0.020" of topography to it!) and turbo have been reinstalled. Rebuilt compressor head is back on as well.

New oil pump:

A few components back on the motor:

The IFS filter kit is in my hands and I am working on adapting the C7 pre-HEUI filter to my 3126- going to try to pick up the C7 block feed line and inline filter this morning. I am a few new o-rings and gaskets away from being able to reinstall the HUEI pump and then need to pre-assemble my induction piping to figure out the lines situation for all the plumbing changes.

Hoping to have it back up and running again soon!

 

[ckouba]

Excellent news- up and running smoothly!!

Got all the pieces back into the proper places, poured in some coolant and fresh synthetic, and fired up the motor on Sat afternoon. Quite happily, nothing went crash, crunch, or bang, and nothing started knocking. I tried to get it primed by pulling out the motor ECM's breaker so I could build oil pressure before starting it "for real", but didn't realize I pulled the wrong one and it actually fired up after a few seconds of spinning. The good news is with the way the HEUI system works, it really can't fire up without oil pressure.

I had it idling while I watched on CAT ET and after an understandable initial code for erratic HEUI pressure (or something like that), the CEL light stayed off and it just idled wonderfully. It was quite rewarding to see "Active Codes [0]" on the CAT ET screen. I ran the diagnostics again and everything was within a very tight band across the desired and achieved pressures. It appears the operation was a success. I had it running 30-40 minutes and got it up to ~150°, where I called it good.

Yesterday, I finally had it out on the open road again- and it felt wonderful. It might be psychological, but it felt smoother under power. I need to head back under the cab though as it sounds like I have a boost leak. I wasn't happy with a few of the hose clamps and have already replaced some, looks like it's time to do all the others. Other than that, I need to follow up on a possible seep of oil from back behind the compressor. It was very small run of oil and may be residual leaking out from all which was spilled over the course of the work performed, but it may be something I need to actually tighten. All in all, VERY happy to have it back together again!

Next up is to rebuild the bathroom into useable condition following its teardown before distracted by the HEUI issue. We leave in 2 weeks for our next trip to UT, so I will remain pretty busy. At this point, the indoor shower will wait until we return and the bathroom will be restored to a single function space for now.

 

[ckouba]

My windshield was in decent shape, but there were a few scratches on it which were annoying. Conveniently, they were on the wife's side, but Rick stumbled across a sweet deal and scored one for me. Yesterday, it went in.

Removal

During

After

They started on Rick's first, and there was a 3x learning curve... then they did mine in one shot. Took it out for big drive afterward and all went very well. I think there were some residual air pockets in the HEUI plumbing as it spun freely but had been a little hesitant to start. That is now completely gone and it starts up just like it did before I tore it down- seems like it's running within a few revolutions. Can't complain about that.

After not leaking while it was idling during the post-rebuild checkout, it embarrassingly managed to drip a few drops of oil at Rick's place. I believe that was all spillage from the work finally getting warm and flowing off whatever components to which it was adhering. The good news is that it seems to have abated and is dry and clean this morning.

This all bodes well for the next adventure- we are heading back to Utah and Arizona on Thurs. This was supposed to be the first trip, but I was worried about not getting a permit and hedged our bets by trying for and getting one in Feb. One of the friends who I organized to go on this trip with secured one for this window so we get to go again.

It will be the same start to the trip, but it's pretty loosely defined once we get south of SLC- or over toward Helper and Price actually. We will meander our way through the San Rafael Swell and into Capitol Reef NP before getting to the Wave, and then we'll spend a little time in that neighborhood, basically running the itinerary which we wanted to do in Feb but bailed on. I will start another thread in the MTV forum for that trip.