M1083A1 Starting Issues

[TomTime]

Hello everyone, I didn't want to hijack anyone else's posting so I'm starting this one. If this needs to be moved somewhere else, okay. Sorry if this thread is long but I want to get out as much info as possible.

My truck is a 2002 Stewart & Stevenson M1083A1, 3126 Caterpillar. I purchased it through GovPlanet as a crank but no start truck and other issues! Since taking the truck into my possession I have been working on numerous issues with it between work, family, and honey-do's.

First off I wash and cleaned the truck inside and out and replaced all, yes all four batteries. Cleaned the battery box, cleaned, checked and coated all battery cable once installed. Cables and voltages are good. Batteries put on trickle charger. Tried starting it again with the same results, crank, no start. Power was going to K11 and K26 LED lights up.

(In between trying to get the engine running, I done a lot. Replaced the water separator/prime pump, replaced the fuel filter, blasted and powder coated all the wheels and replaced all the tires, replaced the rear sway arm bushings, replaced tie rod and drag link grease cups, had all 3 drive shafts rebuilt, cleaned the fuel tank and replaced the pickup and new fuel, rebuilt the AHU, fixed the door closing and window closing issues, keyed the door locks, replaced the seats, rebuilt and painted the troop seats, put on new bed cover kit, changed all lights to LED, except the headlight at this time, replaced rear glad hands and tubing, replaced all mud flaps, and much more)

Took apart the battery disconnect box and cleaned all part and wires and terminals and reinstalled. All good, good voltage before and after the disconnect. Took all the wires off the LBCD, cleaned lugs, wires and contacts, used dielectric grease, reconnected and all good with voltage check.

So over the past couple month I have been reading a lot of the TM's, reading a heck of a lot of SS post and watched a lot youtube videos (holly crap, my mind is now mush!). Issues I have was trying to get straight is difference between the A0 and A1's, especially with the electrical system, when trying to trouble shoot.

Removed the PDP and checked the circuit board, looked great, really clean, and good solder joints. Removed and cleaned all the connection points on the board and replaced all the relays and circuit breakers, top and bottom. Crank, no start.

I tried to find every electrical connection I could find, clean and use dielectric grease and reconnect. Crank, no start.

Going on info from SS posts and Adept Ape youtube videos I checked the ECM and EMI. Checked for the voltages on the 70 pin connector and all looked good from the info I had. Connections were cleaned and reinstalled. Crank, no start.

So, now to the HEUI which I have no knowledge except from what I read and viewed. I check all the connections and did everything Adept Ape suggested. Crank, no start.
Now to the injectors. Per Adept Ape youtube instructions I removed the valve cover and check the voltage going to the injectors. No voltage found coming to the injectors...ECM?

I removed all the wire connections to the aux relay for the starter and cleaned and checked the wires, reinstalled. I also removed the four connections to the alternator and the ground strap and found the one front connections, the front wire beside the LED light was only connected by a couple strands of wire. Cleaned all the connection and replaced the bad one and reinstalled. NO START...WTH? K11 is now not energized and LED light is out. Went back and checked all the connections and the wires I had just cleaned. Could not find a problem so I checked for continuity on the wires I cleaned and all were good, at least as far as I could see. OMG, I smell toast, do you smell toast?

Well, the no start issue has me perplexed. What the hell did I do?

Well, for the crank no start issue that I had, I'm now thinking it is the ECM or the HEUI pump for the no start issue, so I went to my last resort and called a diesel mechanic with a computer to talk to the truck and to see if he can find the problem.

It's now Tuesday, and the mechanic showed up. He checked out the engine out and set up his computer. I told him about the no crank issue now and he put on the remote start switch on the aux starter relay. Well, to try to make this long thread shorter, he worked on it for about 45 minutes and could not get it to start. He said that the ECM was talking to his computer and after check the HEUI he seemed a little stump. He said that it my be the injectors. I told him my issue with checking for voltage on the injections and not finding any. He bled the fuel lines and said that there was a lot fuel pressure going into the head. He took off the valve cover and commented that the truck must have been sitting for years to have so much rust on top of the rocker arms like that. He said that last seen that much rust on the rocker arms was with a truck he worked on that had been setting for 4-5 years. He cranked the engine several different times and said that he through it is the injectors. As he was cranking the engine I checked for voltage to the injectors but could not fine any. The mechanic didn't seemed concerned and continued his work.

For about 30 minutes he tried to start the engine while hitting the injectors with a mallet. After about 20 minutes white smoke starting coming out the exhaust pipe. After about another 10 minutes you could tell the engine wanted to start, smoking more and engine speed getting faster. Another 6-7 minutes of beating on the injectors the engine started running but was putting out a lot of dark smoke. After running for several minutes the smoke lighten up a little but was still dark smoke. I checked for blowby and found some, but the engine was running now, and that was a huge plus for me!!! The mechanic said that the injectors were frozen up probably from sitting for a long period of time. Injectors, who knew???

The alternator seems to be working, the LED's on the alternator are flashing green...I guess that is good? The compressor was producing air and no unusual noises were found at this time, yeah!

The mechanic said that the smoke could clear up with running the engine and putting a load on it, driving it, or it may need new injectors...who knows? WHO? The blowby is probably a ring issue, but I will take care of that a little later. I ran the engine for 30-35 minutes but the smoke didn't clear up or get any lighter.

I spent all that time looking and checking for things that it wasn't, but at least I know the truck better now and the things I worked on are better, EXCEPT, for the no crank issue now at the cab start button.

Checked the transmission selector for codes. Turn on power and "N" shows on the single window. On initial power activation the mode light comes on and then goes out. Checked for codes and this is what it displays:
d111323
d2-
d3-
d4-
d5-

I've been trying to figure out what happened from the "cranking no start" to the no "cranking now". I'm just a little frustrated right now and having a big brain fart!

So, I and could use a little help and direction with the no crank issue now, please!

Also, any suggestions with the engine smoking/injectors?

I have found reman injectors that will replace the ones in the truck for, $300 each...comments?

Tom.

 

[Ronmar]

I would start with an oil stiction additive.

the heui injectors use electric spool valves with close tolerances. Engine Oil quality is important. The black smoke is probsbly the spools not closing cleanly and causing the injectors to dump extra fuel. Diesels like to be warm and loaded, so I would work your runs in tgat direction.

So you flip on the main switch and it wont crank? I can give you some hints to look at, just not right now

 

[Ronmar]

Ok, so when you turn on the main switch, do you get a low oil pressure light on the dash? Do you also get relay K26(neutral) and K11(alt excite) relays energizing?

You need these 3 things to enable the start circuit. The trans controller powers K26 when in neutral. K26 in turn provides power for K11s coil and the low oil pressure switch provides a path to ground to energize K11(and the oil light) when the oil pressure is below 15PSI. The energized contacts of K11 provides 24V to the start switches. If you have the three things above, have you tried both start switches(button and start switch inboard of the right front tire)?

If you have the first 3 items, When you close a start switch, it provides 24V to the aux start relay down on the drivers frame rail adjacent to the starter. So it should be going click when you activate a start switch.

The aux start relay when energized, closes a circuit between the main 24V line attached to the starter and the starter solenoid to energize it.

So what‘s coming on when you turn on the switch, and what‘s happening when you use a start switch?

 

[TomTime]

Okay. Before I cleaned the contacts on the Aux. stater relay, and with the power switch on, K11 and K26 were energizing and showing LED lights lit. Also the dash display showed "Engine Oil Pressure" in the top left corner, "Check Trans" upper middle, "Park Brake" top to the right of the check trans, and "Charging System" on the top right, all lit up. When I pushed the dash starter button the engine would crank over, but no start (now I know it was the injectors) See photographs.

After cleaning the Aux. starter relay contact/wire terminals, and with the power switch on, the "Engine Oil Pressure" light on the dash is NOT lit and also K11 is not energized and the LED light is NOT on. K26 is energized and the LED is still lit. When I push the dash starter button, no crank and no sounds.

Something I remembered doing after posting. I did fumble around with the oil pressure sending unit to see if the wire was connected and had moved the wire around. Wasn't sure if the sending unit was a unit with a wire attached with a post and nut or if the unit was wired into the unit. It was wired into the unit. I went out and disconnected the oil pressure sending unit and checked it with a ohm meter to see if it still had a ground and it did. Didn't know how to check the positive side. Since the "Engine Oil Pressure" light is not lit up on the dash now, could it be the problem?

Also when the mechanic was here I checked the contacts on the aux. starter relay and had him push the dash starter button with the power switch on, and got no voltage reading.

Haven't check with the starter switch on the right side passenger side by the right front tire recently. Did check it when I first got the truck and it did not work.

So that's where I'm at now.

Thanks for replying!

EDIT: See pictures, 3, 4, and 5. That is the oil sending unit, the dark colored item? What is the silver unit in front of it?

Also I have a video of it but don't know how to get it to post.

 

[Ronmar]

The same circuit that powers the oil light on the dash also controls K11. No dash oil light or K11, no start.

There are 2 oil pressure sensors, in your pic, the large one on top of the small oil manifold drives the oil pressure gauge, the smaller one on the oil manifold pointing toward the rear of the vehicle with the wires coming out of it is the 15 PSI low oil pressure switch. It is normally closed, and opens when the oil pressure goes above 15 PSI. Its wire runs to a 2 pin connector, separate that connector and with an ohm meter on the leads back to the switch, you should see a short/low resistance path thru the switch, with the engine not running.

If you take the other side of that connector back toward the truck, and place an electrical jumper connecting its 2 pins, this will simulate the closed pressure switch. you should once again have an oil pressure light in the dash and K11 powered. The engine should then crank with either start switch…

once the engine starts, the oil pressure sw opens, the light goes out and K11 de-energizes. This disables the starter so you don’t try and crank a running engine, and the de-energized contacts of K11 power the EXC terminal on the alternator, bring it online…

 

[TomTime]

You are the man, @Ronmar !!!

Disconnected the oil sensor connector and jumped the connector going to the truck. The "Engine Oil Pressure" light on the dash came on along with the K11 LED light. I pushed the starter button and she came alive. Also tried the remote start by the front right side tire and it worked also. Photographs below are with the engine running.

With that jumper wire connected and the engine running the alternator LED's are NOT flashing now (they were before when started by remote starter on the aux. starter relay). Also the Engine Oil Pressure light on the dash panel stays lit. Can I assume that there needs to be a good oil pressure sensor with a good connection to have the alternator working again and the Engine Oil Pressure light to go out?

So, I guess I need a new oil pressure sensor/sending unit? I been looking for a new oil pressure sensor and can't find one that matches the one I have with the same connector. Eastern Surplus has a photograph of one which matches the one on the truck but has none in stock. Can't seem to locate one.

Now for a oil change and new filter today.

Thank you very much for your help, I greatly appreciate it !!!

Tom.

 

[Ronmar]

Yep, you need a functional oil sw for evertthing to work as intended. the oil pressure switch controls oil light and via K11 the starter and alternator.

Those Nason switches are not all that common, but a 1/8” NPT threaded, 15PSI N.C(normally closed) oil pressure sw can be had at any auto parts store… Since they are a common part, they are not very expensive…

The only thing special about the one on the LMTV is that it has 2 wires. Most oil pressure switches only have one wire/connection and when closed provide a path to ground thru the switch body/engine block Below 15 PSI.

On that oil switch wire you jumped, one wire will have voltage on it(with main sw on) when measured to ground, and the other will have a low resistance path to ground. You can determine which is which with your meter. You can put in a OP sw from your local auto parts store(1/8” NPT threads). Then cut the wire harness off the old sw To connect the new sw to the truck harness using the existing connector.

Determine which of the two cut wires on the old sw harness is the powered wire from the truck light/K11 and connect that wire to the new switches single terminal. Tape or heat-shrink the now unused ground wire on the old sw harness… The block is already grounded so this should work just fine for this circuit…

 

[GeneralDisorder]

You'll likely want to replace those injectors. And with all that rust on the inside of the engine you should swap out the HEUI oil feed line to the updated CAT part with the filter element integrated into it and cross your fingers the HEUI pump survives - iron oxide is REALLY abrasive stuff. The CAT parts I used on my 2008 C7 (should be the same as the 3126b):

129-2327 (HEUI pump elbow adapter)
238-5081 (High pressure o-ring)
503-7469 (Hose assembly)
503-7470 (In-Line Filter)
1359819 (FP Diesel branded compressor to timing case gasket)

 

[TomTime]

Well, found that the oil pressure switch does work but one of the wires that goes into the connector was partially pulled out of the connector. Fixed that issue and reinstalled until I get one to replace it…Engine running.
Changed the oil and filter, it was real dirty and black.
Friday I broke down, yes I was sobbing and purchase 6 reman injectors $$$.
@GeneralDisorder thanks for the info on the HEUI fuel lines, I’m checking into that tomorrow. By the way how hard was that to install. I’m assuming the compressor comes off any anything else?
Installing injectors tomorrow as long as the weather holds up.
…and I have to say it again, thanks to @Ronmar for all your help!!!

 

[GeneralDisorder]

Correct - compressor and hydraulic pump (power steering) need to be removed. Make sure the Nord-Lock washers are in place on the rear support bracket. Nothing difficult just time consuming and the compressor/pump assembly is rather heavy. I did it without a helper but that was probably stupid.

My compressor blew up (valves disintegrated and punched a hole in a piston) because the air dryer cartridge wasn't serviced EVER in the life of my truck so I had to pull my compressor anyway - it was beyond repair but fortunately I have a local place that specializes in air brake systems and found me a rebuildable core. If you haven't serviced the dryer do it now. So while I was in there I installed the updated filter and hose - hose was showing signs of age anyway.

Fortunately my truck sat in the desert it's whole life (Kuwait, and El-Paso) and my engine only had 2750 miles on it when I got it so internally it's perfect. Everything that's rubber is falling off my truck in pieces but mechanically it was perfect. Got to love that dry air storage. I've seen trucks with similar mileage to mine with injector problems because they mostly sit not being run here in Oregon (guard and reserves) and the moisture causes problems. Even when they do run they spend a LOT of time idling well below any temp that would drive off moisture. I pulled the data from my CAT engine computer and my truck had something like 500 hours of operation for 2750 miles. That's an average of 5.5 MPH.

 

[TomTime]

I purchase the rebuilt kit for the air dryer last year and was going to rebuild the kit last fall but cold weather caught up with me.
After I put the injectors in that is my next project along with a few new air lines. After that, drain and flush the transmission and refill with ATF.

 

[TomTime]

Well, installed the injectors today. First time for everything. I took my time to make sure everything went well. Took about about 6 hours from beginning to clean up, and my back is killing me.
The old injectors appear to have a lot of carbon build up on the tip, no wonder it was smoking so much.
First start of the engine just after installing the injectors the smoking had decreased about 70%, but still smoking. Left it run for awhile then shut it down. Left it sit for about 30 minutes and restarted it and it seemed like the smoke had decreased a little more. Left it run for about 15 minutes and shut it down again. Restarted it about 30 minutes later and barely any smoke could be seen .
Also, since the oil and filter change there is now no visible blowby out of the oil filler port,

Next up, transmission drain, flush and refill, air dyer rebuilt, and HEUI oil feed line, not necessarily in that order.

 

[Ronmar]

It was probably just getting to proper temp by that point Did you get it warm enough for the fan to engage? Does this rig have a warmup switch(Engages ex brake to load engine)? Diesels like load, you can also chock the wheels and put it in drive to get it to full op temp/engage the fan…

 

[TomTime]

It was probably just getting to proper temp by that point Did you get it warm enough for the fan to engage? Does this rig have a warmup switch(Engages ex brake to load engine)? Diesels like load, you can also chock the wheels and put it in drive to get it to full op temp/engage the fan…

Humm...the fan. Well, when starting the engine the fan is turning and continues to turn. Really never gave it any thought until you just brought it up. I guess another issue to deal with. Any suggestions at this time?

 

[GeneralDisorder]

Fan will always turn even when not "engaged". It will lock in the pneumatic clutch at 200 degrees and it will REALLY turn. You can hear it moving serious air when you rev the engine or drive.

 

[Ronmar]

If you reach up under the radiator before you turn the truck on, the fan should be locked. When you turn on the main switch, with air in the tanks, the fan should release/freewheel. The thermal switch removes power to the fan solenoid which removes air to engage the fan at 205F. You should hear the same woosh of air you hear when y0u turn off the main switch. As mentioned, the bearing drag is enough to spin the fan pretty well, but when it engages, it roars… even freewheeling it moves a significant ammount of air.

 

[TomTime]

If you reach up under the radiator before you turn the truck on, the fan should be locked. When you turn on the main switch, with air in the tanks, the fan should release/freewheel. The thermal switch removes power to the fan solenoid which removes air to engage the fan at 205F. You should hear the same woosh of air you hear when y0u turn off the main switch. As mentioned, the bearing drag is enough to spin the fan pretty well, but when it engages, it roars… even freewheeling it moves a significant amount of air.

When I received the truck I noticed that the fan would not move while the engine was not running. Checked It again today and it is the same, doesn't move.
As I said, the fan moves with the starting of the engine and stays rotating. It moves some air at idle and when I rev the engine it doesn't change much, no massive air flow, so I think I'm good.

The following video shows the truck running just after the new injectors were installed and new oil and filter change. You can see the fan moving, the smoking on the first start and now no blowby. As I said before, the smoking subsided after 3-4 different starts.
Sorry, first time putting a video on youtube, not sure how that is going to come out. Also not the best at taking videos either.

Thanks again for all the replies and help, @Ronmar & @GeneralDisorder , you guys are great!

Tom.

 

[Ronmar]

Well like I said above, if you have air in the tanks, and you turn on the main switch, you should be able to rotate the fan freely. This is a good thing to do from time to time anyway, spin it and wiggle it around, see how much slop and drag the bearings have since those bearings are freewheeling and in use most of the time the engine is running. But because of that drag the fan will always spin, it just wont roar until engaged…

 

[TomTime]

Well like I said above, if you have air in the tanks, and you turn on the main switch, you should be able to rotate the fan freely. This is a good thing to do from time to time anyway, spin it and wiggle it around, see how much slop and drag the bearings have since those bearings are freewheeling and in use most of the time the engine is running. But because of that drag the fan will always spin, it just wont roar until engaged…

Well, was able to get back to the truck yesterday evening. Air tanks full, main switch on, fan won't budge. Bearings?

 

[Ronmar]

Well, was able to get back to the truck yesterday evening. Air tanks full, main switch on, fan won't budge. Bearings?

More likely fan solenoid Or control. Do you hear a whoosh of air from the passenger dash area when you turn off the main switch?

The fan control solenoid is under the far right end of the passenger dash. It is right above eye level when standing beside the truck in the passenger door, with the kick panel removed.

The fan control is kind of reverse logic. It applies air to release the clutch and allow it to freewheel. So the 205F thermal switch in the upper radiator pipe(A0) or the ECU(A1) provides switched 24V power to the solenoid to energize it, which provides air to allow the clutch to freewheel. When the coolant in the upper radiator pipe reaches 205F, that switch(or the ECU on the A1) opens the solenoid circuit, which de-energizes and vents air with a woosh in the cab, and the fan engages. Turning off the main switch does the same thing, removes power to that solenoid valve and lets it vent the fan clutch air.

The fording switch is in parallel with the thermal switch and overrides it, providing 24V to keep the solenoid powered and the fan freewheeling. I believe fan power is provided by CB22(or the ECU)

If that solenoid is not energizing, first thing I would try is confirm CB22 is providing power, then turn on the fording sw. It provides power independent of the ECU so that might rule it out. Next I would look for 24V at the connector of the solenoid with main and fording sw on. If it is missing, well you need to dig back into the circuit to find out why. If it is there, I came up with a lower cost alternative to the rare original fan solenoid last year. Here is a link to the Youtube vid I did on it…