Just another day in paradise

Mike L said:

I saw the timing marks and they were lined up. The heui pump doesn’t have marks and I’ve always just put them in.

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Ah, missed the part about you doing the rebuild.

Coworker just got stuck on a very old dozer project the owners friend had helped "overhaul" and my coworker had to break it to the guy it was better to start over than chase problems. Thought you were in a similar situation.

I didn’t do the overhaul. The engine was from cat and the front cover wasn’t on it so I saw the timing marks there

Some of those high pressure pumps have to be timed. This one doesn’t - I checked.

I didn’t know that. I’ve done a few and have never seen a timing mark.

Around minute 5:16 is a sample screen of what Nige was speaking about with ET parameters. Don't know if it'll help but I know I do better with pictures.

Okay so here is the latest on the D6T. Apparently my customer has some pull with the cat dealer a state over. They loaned us a test ecm. I put it on, hit the key, and she fired right up. So now a new ecm is ordered and will hopefully be here next week. So then we got thinking. When I was putting the engine in there was a pile of fuel in the muffler. I turned it upside down and dumped it out. The last people who worked on it thought it needed Injectors and then proceeded to install them with a hammer, then couldn’t get it to run. When I was trying to start it with the faulty ecm it was smoking excessively. I think the last guys misdiagnosed a bad ecm, threw injectors in it, and then cranked it which filled the cylinders with raw fuel and hydrolocked it, causing internal damage. Thoughts?
Now here is my cat et/sis question of the day. When I plug into a machine and it has codes, where do I find the description of what sets the code and how to diagnose it?

On some of the menus, you can click on the code number and it will take you to a summary explanation of the code. Any more than that and I think you need the book.

I’ve seen that on Deere and cummins but for some reason I didn’t think cat did the same thing. Maybe I clicked in the wrong place.

If you click the troubleshoot link in ET it should take you to the manual in SIS but so far that has never worked even once for me. It always takes me to the SIS home page. What I do is for a code 3761-4 search for the first part of the code 3761 then look for the dash number and that should provide all the troubelshooting trees. I like leaving the previous windows and open new windows can be a pain to find the previous reference.

Mike L said:

Now here is my cat et/sis question of the day. When I plug into a machine and it has codes, where do I find the description of what sets the code and how to diagnose it?

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JohnC is correct. Sometimes, but not always, in ET if you highlight the Diagnostic Code you can right click and it takes you to a troubleshooting procedure.

Do you have online access to SIS.? The great thing about SIS2.0 is that you can open it in multiple windows, even using different Serial Numbers, and dive off in different directions without affecting whatever other windows you have open.

A suggestion. Find Special Instruction REHS0126 and create a pdf copy. I think it's about 200 pages now. That can provide your "Bible" for Diagnostic and Event Codes.

I’m not sure if I have online access and I have the old version of sis. Not 2.0.

Even if you have offline SIS and it's the old version REHS0126 should still be there in some form or other. The only question will be the Change Level, the numbers after the dash in other words. See if you can find it in your version of SIS and post back what change level you find. I think in my history files the oldest one I have is from about 20 years ago, version 03 IIRC.

so here’s my latest cat conundrum. 3412e. S.n. Bdt03561. unit is in a diamond z tub grinder. Crank no start. No codes. Checked the low pressure fuel syste. Plenty of fuel. Injection actuation psi needs to be 700-900 and within 200 psi of requested pressure. The pressure sensor reads 250 at all times, even removed and hanging in the atmosphere. The only time it changes is if I unplug it, I get a voltage high code. I replaced the sensor with no change. I have a couple questions. First, if I only read 250 psi then am I correct in thinking the ecm won’t energize the iap control valve to allow the injectors to fire? Secondly I’m thinking I have a wire issue going to the sensor. It is a 3 wire sensor. #167-1709. Where in sis do I find the testing procedure for the sensor? I didn’t have much time today to work on it but my next plan of attack is to put a gauge in the pressure port to see what actuation pressure I actually have and to chase the wiring.

Actual & Desired IAP are on consecutive lines of the screen IIRC

If Actual IAP does not reach Desired IAP (or preferably exceed it) during cranking the ECM will not send the command to light the fires and therefore no smoke from the chimley......

I dunno if the latest versions of ET have it but there used to be a row of "Status Flag" boxes at the bottom of the screen. When a HEUI engine was stopped one of the boxes had an "Injection Disabled" message in it. You could watch the Actual IAP coming up during cranking and as soon as it passed the Desired IAP the Injection Disabled message would disappear, followed a split second later by a cloud of black smoke........

You won't get any Diagnostic Codes for Actual IAP failing to exceed Desired IAP during cranking.
I used to like to see a HEUI cranking at something close to 200 RPM on the starter.

Another thought. Check the Part # of the installed software and of the injectors and post back. It won't be the first one I've come across where the software P/N and that of the injectors didn't correspond.

For an IAP sensor testing procedure try looking in the Troubleshooting section for CID0164 FMI03 (Engine Sensor Open/Short Circuit - Test).
Also look for "Injection Actuation Pressure Control Valve Circuit - Test".

Here's another thought/question. What's the back story on the engine.?
Did it start OK cold then got harder & harder to start hot until one day it wouldn't start at all, even when cold, OR......... was it running and just quit like someone turned off the key.?
If the latter then my suspicion would be that the drive to the HEUI pump has let go. They were somewhat famous for that back in the day.

The back story was that it just quit. When you say the heui drive let go you mean like if I removed it the pump would be visibly broken or just doesn’t work anymore?

There is a splined drive coupling on the input side of the pump. If you slide the pump back a bit it ought to be possible to inspect the spline condition. A failed coupling will be immediately obvious because the splines will have disappeared, more on the female side than the pump shaft IIRC.

I'm not saying the problem might not be electronic, but the way you say the engine stopped the first thing that sprung to mind was that drive coupling. They hang on to the splines until the last moment then simply let go.

Oh, and another thing. The coupler arrowed on the RH illustration runs on two bushings. If either or both of them gets signifcant wear it can take out the splines quickly. Look at 180-6644 DRIVE GP-UNIT INJ HYD PUMP on SIS.

I can’t explain it but I’ll report it. I went back today and worked on the engine. I checked My wiring to the sensor and it all checked out. I remover the sensor and put a test fitting in to check what my actual iap pressure was. With the sensor out and unplugged the iap pressure was well over 3000. Hmm. I plugged in the sensor and and tried again. This time it read around 900. thought it was weird so I did it again to make sure I hadn’t finally lost my mind and it did the same. so I reinstalled the sensor and put the pressure fitting in the other head. I hit the key and I’ll be damned it started and ran. ET still read that I had 250 psi with the engine off but it did read pressure while it was running. All I can think is that i may have a broken wire somewhere and with all my screwing around I made a contact somehow. We’ll see What happens. The tub needs a pile of work and the customer just wanted to see if I could get it running.

Mike L said:

All I can think is that i may have a broken wire somewhere and with all my screwing around I made a contact somehow.

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This has happened to me more than I care to admit. It can be really rewarding to find the broken copper, hidden by the intact insulation.
Driver's door harness from the door to the body, broken at the bend......