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And the GMTDScanner Says

Big T

Big T

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Location
Fullerton, CA
I need to some work, but looking for confirmation here.

I get the following codes:

Current Codes:
34 - Injection timing stepping motor fault
91 - Cylinder balance fault #7 cylinder
88 - TDC Offset error

Historic Codes:
34 - Injection timing stepping motor fault
91 - Cylinder balance fault #7 cylinder
88 - TDC Offset error
95 - Cylinder balance fault #4 cylinder

Under TDC at idle:
Desired Timing: 8.6
Acutal Timing: 20 to 22
TDC offset: -2.02

If I read this correctly, then my timing is off by 10 degrees plus the TDC offset, which means that I'm off by a tooth on the bottom timing chain sprocket. I'm looking for confirmation before I start tearing it down.

Thanks in advance,

Big T :sad:
 
Last edited:
PM ChrisK1500 if he doesn't see this first. He would know. The -2.02 would set the code 88 . I'd clear them and see which ones come back as well.
 
I would try rotating the pump before tearing things down. Loosen the three bolts, rotate it, clear the codes and see if it will command a TDCO learn.
 
I spoke with with Heath Diesel on this and they said that the codes shown and the timing indication were consistent with the timing being incorrectly set internally. Couple that with the dealer comments that they too were unable to set the timing and pointed to the timing being set incorrectly internally. So after runnind down a gasket kit, about 2:30 PM yesterday I started tearing it down and I'm to the point of removing the timing gears and cover.
 
The marks were well off. Total brain fart on that. :dr:

It's almost back together: crossover, alternator and power steering bracket, radiator, fan and serp belt. S/B done tomorrow morning.
 
96 OILBURNER said:
Good thing it wasn't off enough to smack a valve. :)
Click to expand...

Yep. Someone was looking after me on that. Just thinking about it, I need another beer. :rolleyes5:

Look at it this way, when you think you've got it bad, someone else has got it worse. For example, about now Tiger Woods is probably regripping his clubs and ordering up a Kobe Special.
 
Big T said:
The marks were well off. Total brain fart on that. :dr:

It's almost back together: crossover, alternator and power steering bracket, radiator, fan and serp belt. S/B done tomorrow morning.
Click to expand...
You live you learn:D

Like the carpenter says ,measure twice, cut once.
 
Practice makes perfect. I had to try 3 times to get things lined up right on my 95ld. I really didn't want this to happen. So it isn't hard at all to get the marks not lined up. I don't think there is any of us that hasn't had a brain fart.
 
"Couple that with the dealer comments that they too were unable to set the timing and pointed to the timing being set incorrectly internally"




Holy crap, this means the Stealer was right this time!:eek::eek::eek:
 
Mudbath said:
"Couple that with the dealer comments that they too were unable to set the timing and pointed to the timing being set incorrectly internally"




Holy crap, this means the Stealer was right this time!:eek::eek::eek:
Click to expand...

And the dealer tech was "Where do they find them and why do they bring them to me?!" :D
 
In talking with Todd at Heath, he said it's very common for the cam to move while removing the timing chain sprockets. The valve springs exert 500 lbs of force and the cam will move to the point of lea st resistance. We were working fast to beat the remaining light in the day so that my son could use the truck for his Thanksgiving hunting trip. We thought we had it, but obviously not.

Definitely the carpenter's rule this time, measure twice:

IMG_0853.jpg

IMG_0851.jpg


To give you an idea of where I set it previously, with the mark on the upper cam sprocket at the 6 o'clock position, the mark on the crank sprocket was at 10 o'clock, or about 2 teeth to the left.

The local stealership has been pretty good with the diesel diagnosis, with the exception that they screwed me on the IP replacement. I had been having the regular problems for a year and went with the remote PMD mount, but still had stalling problems. It was very sporadic (i.e. once in 6 months) and waited until it was bad before bringing it in. Finally they concluded I needed a new IP, but my truck was originally purchased in Feb '05 (I'm second owner) and it was April '06. So it was just outside the 11-year warranty/recall period and they refused to replace under warranty, despite my record with them. I had to fork $3K. Got a new pump and that one was faulty in short order and was replaced under warranty. Been fine ever since. I was so miffed over that experience that I never brought it back to them. I had to do it this last time due to the time constraints and my then inability to assess and set the timing. Now that I have GMTDScan and all of the wonderful shared experience here, I am completely free of stealership dependency.:D
 
Big T said:
In talking with Todd at Heath, he said it's very common for the cam to move while removing the timing chain sprockets. The valve springs exert 500 lbs of force and the cam will move to the point of lea st resistance. We were working fast to beat the remaining light in the day so that my son could use the truck for his Thanksgiving hunting trip. We thought we had it, but obviously not.

Definitely the carpenter's rule this time, measure twice:

IMG_0853.jpg

IMG_0851.jpg


To give you an idea of where I set it previously, with the mark on the upper cam sprocket at the 6 o'clock position, the mark on the crank sprocket was at 10 o'clock, or about 2 teeth to the left.

The local stealership has been pretty good with the diesel diagnosis, with the exception that they screwed me on the IP replacement. I had been having the regular problems for a year and went with the remote PMD mount, but still had stalling problems. It was very sporadic (i.e. once in 6 months) and waited until it was bad before bringing it in. Finally they concluded I needed a new IP, but my truck was originally purchased in Feb '05 (I'm second owner) and it was April '06. So it was just outside the 11-year warranty/recall period and they refused to replace under warranty, despite my record with them. I had to fork $3K. Got a new pump and that one was faulty in short order and was replaced under warranty. Been fine ever since. I was so miffed over that experience that I never brought it back to them. I had to do it this last time due to the time constraints and my then inability to assess and set the timing. Now that I have GMTDScan and all of the wonderful shared experience here, I am completely free of stealership dependency.:D
Click to expand...

Looks good now, we are all witnesses.:thumbsup:
 
Alright, fired it up and it started much easier this time.

Connected to GMTDScan, cleared codes and ran it until it reached 180 F. SES light came on and registered following codes:

34 - Injection Timing Stepper Motor Fault
88 - TDC Offset Error

Went to the TDC tools and got the following readouts

Desired Timing = 8.6
Actual Timing = 17 to 20
TDCO = -2.02

It sounds and runs a lot better. I'm showing two less codes and no longer showing cylinder imbalance errors.

I had to go repurchase a longer Craftsman double box wrench to reach the bottom IP nuts, but I still need to take it to a welder to have it bent.

I read the tech sticky article here on setting TDCO and it says that Desired and Actual Timing should always be within a degree or two of each other, but mine is off about 10 degrees. Obviously my TDCO is over the limit and kicks off the SES code when it reaches temp. I'm at a loss here as to what to do and looking for advice where to go from here.
 
You need to shift the IP toward the passenger side a smidge if you want it at -1.94. It could be a bit more than a smidge since I believe the max reading is -2.02.
 
Alright, went out and attempted to move it. I was finally able to loosen the lower nut on the passenger side, but it took clearing the oil line to the turbo. The pump was a bear to move, but I moved it over a dime's width to the passenger side. Started up and TDCO ended up at 0 with the same differential on Desired and Actual Timing. Went to move it again a hair back towards the driver's side. I'm only locking down the upper IP nut. It's blowing white smoke both times. I cleared the codes and this time I got the following:

Codes:
88 - TDC offset error

TDCO Values (@ 900 RPM idle)
Desired = 15.7
Actual = 16.7
TDCO = -2.02

So I'm down to just one error code and the TDCO is still off. Did not really feel like I even moved the IP. Blowing smoke.

I have the GMTDScan set Timing On and TDCO Learn On. Is there some sort of magic button to make it do its learning thing or am I suppose to keep playing with the IP?

Again, I'm lost here and could really use some help.
 
180 degrees?

Don't understand the comment. Are you saying you think I've set the timing 180 degrees off?
 
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