What would you do?

[DDW]

Guy is here working now. Says he's having to pull the heat exchanger to get to the bolt. It's quite a bit more involved than I'd have thought.

Cummins have an unfortunate habit of burying possible failure points deep below ancillary components. To replace the fuel lift pump on my QSB, I had to remove the intercooler, fuel cooler, fuel manifolds, and ECU. Changing the fuel pump took about 20 minutes, getting to it a couple of hours, and a couple more reassembly It could have as easily been mounted elsewhere, and accessible.

I've long been of the opinion that the engineer than designs these things (and possibly the CEO too) should be required to perform an R&R on any serviceable component in published video prior to first sale. At least the swearing would be amusing, and I'd bet there would be a change in design practice too.

 

[SteveK]

Cummins have an unfortunate habit of burying possible failure points deep below ancillary components. To replace the fuel lift pump on my QSB, I had to remove the intercooler, fuel cooler, fuel manifolds, and ECU. Changing the fuel pump took about 20 minutes, getting to it a couple of hours, and a couple more reassembly It could have as easily been mounted elsewhere, and accessible.

I've long been of the opinion that the engineer than designs these things (and possibly the CEO too) should be required to perform an R&R on any serviceable component in published video prior to first sale. At least the swearing would be amusing, and I'd bet there would be a change in design practice too.

In the past few decades I have seen make work designs for the dealer mechanics. special tools, harder to get at, and so on. Check the oil level was with a dipstick, now I could not find one on wife's car. The dash will read out when you need to do it.

 

[DDW]

The very height of design arrogance is a piece of electronic equipment with no reset button. This is the engineer proclaiming to the world, "I am PERFECT!". Burying serviceable equipment is a lessor example, one can make excuses about 'design tradeoffs'. If there were skin in the game for the designer, behavior would change.

 

[Jklotz]

Job is done now, mechanic said it's ok to drive, although it was throwing a fault code. Something about a crank shaft timing error. He said it was a faulty sensor and is coming back tomorrow to put in a new sensor. Unfortunately, this one is not covered under warranty, but he said he could replace it in 1/2 hour or less.

 

[Fletcher500]

Guy is here working now. Says he's having to pull the heat exchanger to get to the bolt. It's quite a bit more involved than I'd have thought.

As a side note, I find some of the OSHA rules amusing. He had to put a padlock around my key floaty, take a pic of it and send it back to the office before they gave him the go ahead to start.

View attachment 164804

“Amusing”? Lockout/Tagout is an important program that has prevented many injuries involving machinery and electrical. If you had ever worked around heavy equipment you would appreciate that fact.

 

[Delta Riverat]

It is important, especially around big industrial eq where the operating panel might be 100 feet or more from where the guys are working. Here it's more like "stop someone from starting the engine while I'm down here"

 

[Jklotz]

“Amusing”? Lockout/Tagout is an important program that has prevented many injuries involving machinery and electrical. If you had ever worked around heavy equipment you would appreciate that fact.

I understand. Mechanic was a good guy, certainly meant nothing against him. I was just amused he put a pad lock around the floaty. I get the importance of the procedure. I'm not trying to discount that.

 

[rslifkin]

I agree, the padlock around the float is a bit funny. I would have been more inclined to lock the key to something that would actually prevent it from being put in the ignition switch.

 

[slowgoesit]

“Amusing”? Lockout/Tagout is an important program that has prevented many injuries involving machinery and electrical. If you had ever worked around heavy equipment you would appreciate that fact.

The manner in which this ignition key was "locked out" does nothing to prevent the key from being used to attempt to start the ignition.
Granted, the "Tagout" portion of "Lockout/Tagout" was technically complied with, but still does nothing to prevent someone from using the key to engage the engine starter.
Personally, if I were the mechanic, after placing the "Tagout" tag on the key to comply with insurance purposes, I would have placed the ignition key (with the tag) in my pocket to actually preclude the engine from being started and to keep ME safe . . . . but that's just me . . . .

 

[Jklotz]

The manner in which this ignition key was "locked out" does nothing to prevent the key from being used to attempt to start the ignition.
Granted, the "Tagout" portion of "Lockout/Tagout" was technically complied with, but still does nothing to prevent someone from using the key to engage the engine starter.
Personally, if I were the mechanic, after placing the "Tagout" tag on the key to comply with insurance purposes, I would have placed the ignition key (with the tag) in my pocket to actually preclude the engine from being started and to keep ME safe . . . . but that's just me . . . .

I hear you. It was just me and him on the boat though and I got the message loud and clear.

 

[slowgoesit]

I hear you. It was just me and him on the boat though and I got the message loud and clear.

Hopefully the sensor replacement will make this entire issue a distant memory! Now, just need to get out and get cruising!

 

[Fletcher500]

The manner in which this ignition key was "locked out" does nothing to prevent the key from being used to attempt to start the ignition.
Granted, the "Tagout" portion of "Lockout/Tagout" was technically complied with, but still does nothing to prevent someone from using the key to engage the engine starter.
Personally, if I were the mechanic, after placing the "Tagout" tag on the key to comply with insurance purposes, I would have placed the ignition key (with the tag) in my pocket to actually preclude the engine from being started and to keep ME safe . . . . but that's just me . . . .

Slow; I realize that. The Tag Out was deemed enough by the Tech and their company procedures in this case. He also likely pulled the power cord to the ECM which rendered the key useless regardless.

OP; good to hear you are on the move again. I was following your thread closely because we share the same engine and my ears perk up when some mentions fuel issues. Keep us posted on how things go.

 

[DDW]

You can always use your second key to kill the mechanic.

 

[Jklotz]

Today he replaced the crankshaft position sensor. I had to pay for that one, but we should be good to go now.

 

[Jklotz]

Question: This could be my imagination, but it seems like the engine is running smoother since the crankshaft position sensor was replaced. (The old one was a bit mangled on the sensor end, and the part has since been redesigned, new one in place now). Is that possible or am I imagining things?

 

[KnotYet]

Question: This could be my imagination, but it seems like the engine is running smoother since the crankshaft position sensor was replaced. (The old one was a bit mangled on the sensor end, and the part has since been redesigned, new one in place now). Is that possible or am I imagining things?

Several possible explanations come to mind. Maybe the new sensor resulted in better timing?

 

[DDW]

The crankshaft position sensor is everything to a common rail diesel. Absolutely a malfunctioning or weak one could cause rough running. All of the injection timing is based on it, to a fine degree.

 

[SteveK]

The crankshaft position sensor is everything to a common rail diesel. Absolutely a malfunctioning or weak one could cause rough running. All of the injection timing is based on it, to a fine degree.

So would it damage a fuel pump?

 

[DDW]

No, fuel pump just keeps the common rail at pressure. ECU fires the injectors (more than once per stroke on modern engines) in precise locations relative to TDC - determined by the position sensor. Most likely independent problems.

 

[Fletcher500]

DDW, I thought the crankshaft sensor was monitoring the engine rpm, rather than crank position, to determine injector firing?

 

[DDW]

There are two sensors, a crankshaft and a camshaft position sensor. The ECU needs crank and cam position to determine the injector timing, and rpm (which it can get from either of those) to determine injector frequency. I don't know what the workload is between those two on the QSB6.7, some early common rail diesels only had a camshaft sensor but of course it has only half the resolution of the crank. They are sensitive enough and resolved fine enough to identify the crank acceleration for each cylinder firing.

In mechanical injection the timing is controlled by the angle of the injection cam relative to the valve cam, this is generally fixed during operation (though there are some engines that vary it). A common rail engine can do whatever it wants, whenever it wants with injection timing, including injecting a bunch of fuel on the exhaust stroke - done for particulate filter regen on over the road diesels. To run the engine efficiently and cleanly (as required by law these days) the timing has to be very precise, can vary a lot, and have many injection events per firing stroke.

On a gas injected engine, it is sufficient to know the rpm, many used to run this way. All the injectors fired at once, the gas cloud is essentially stored in the inlet runner until that cylinder gets around to an intake stroke. Doesn't work with diesel (or direct injection gas).

 

[rslifkin]

On a gas injected engine, it is sufficient to know the rpm, many used to run this way. All the injectors fired at once, the gas cloud is essentially stored in the inlet runner until that cylinder gets around to an intake stroke. Doesn't work with diesel (or direct injection gas).

Even with sequential multiport injection you don't necessarily need fine resolution. But if you only get one sensor trigger per rev then you'll have to crank through a couple of revolutions on startup as you won't have rpm and a reference for where you are in the cycle until you've hit the sensor trigger 2 or 3 times.

 

[DDW]

But on a direct injection gas, you need precise crank position. They also use this for fast starts (applicable in particular to cars that shut the engine off at stops). They know what cylinder is near TDC on compression, inject and fire that cylinder, and the engine practically starts itself.

 

[Fletcher500]

Thank you for the explanations. I had tried to find info on these sensors in the past and couldn't find much, including on SBMAR.