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And the GMTDScanner Says

bison said:
I think the flats on CPS run paralel to the crank shaft
Click to expand...

Yes, I concur, but the CPS could be rotated 180 in its hold down bracket. Does that POSITION make a difference?

From the linked thread:

If I take the mechanics word for it that he did not find the injector pump gear out a tooth, I believe the root cause was that he broke the bracket off the crank position sensor and when he reinstalled it he got it aligned 90 or 180 degress out. This results in the timing being out in relation to true TDC, but correct in relation to the crank sensor.

In the thread I linked, I'm experiencing exactly the same thing as the original poster. Can't get it close enough for Time Set or TDCO Learn. Almost the same readings between Desired and Actual and the same inability to bring it into tolerance (for a Time Set and TDCO Learn) by rotating the IP. Then I read that people were suggesting he must be a tooth off on the timing gears (he wasn't) plus all sorts of other suggestions like IP faults, stepper motor gone bad, etc. The final solution was a new CPS and he concluded that he might have been 90 or 180 off on the CPS because the plastic was broken, thus my question. The plastic was not broken on my CPS, but it definitely could be 180 off in the bracket.

I'm going to pull the CPS vs pulling the water pump again.
 
And that was it!

I pulled the CPS, flipped it 180 and reinstalled. Engine immediately fired up with very little smoke and only for the first second or two. Haven't timed it yet, but it sounds like normal. My marks on the IP are lined up just where they were when I started the original tear down. The thing sounds so close to normal that my dog (English Springer) jumped in through the driver side window with the door closed, thinking we must be going somewhere. Truck is warming up now.

I will post up pics of the CPS as it has marks on it that are definitely position sensitive. The marks need to be towards the radiator. Here's the photo:

IMG_0865.jpg


Notice the two dots. It needs to be installed with those vertically aligned and towards the radiator. There are also two metal strips lined up horizontally on the face of the CPS. One is thicker than the other. These are obviously the sensors and with their size being different, they obviously do different things and their order is important.

Thanks for all the input. It took just a little reading between the lines of all the input here and in that other thread to figure this out. I guess I'm my own trouble shooter. The key was that other thread where the guy was having the exact same problems. Also the realization that I never pulled the CPS the second time I had the cover off. Finally, a big thanks to my wife an her thin arms which came in handy when reinstalling the CPS.
 
Last edited:
Yes we are are own worst enemies. :mad2: But boy do we learn a lot in the process. Glad to see you got things back on track. It always makes perfect sense afterwards!):h
 
OK with temp at 190, I get the following:

Time Set
Desired Actual TDCO
Before 8.6 8.6 -1.23
During 0 3.4 to 3.7 -1.23

TDC Learn
Desired Actual TDCO
After 8.6 8.6 -1.32

So IP twisters, which way do I need to rotate to get to that fabled -1.94 zone? There's still a mm smidge towards driver's side to line up my scribe mark with the chisel mark.
 
Mudbath said:
Yes we are are own worst enemies. :mad2: But boy do we learn a lot in the process. Glad to see you got things back on track. It always makes perfect sense afterwards!):h
Click to expand...

You know, behind the screen I was cussing and swearing at all of you! I just knew that some of the suggestions (were wrong) did not make sense. It took herculean effort to bite my tongue and phrase things in a polite way to continue the feedback coming. Believe me, that's not my normal style. I literally had to read between the lines of all the input vs what I knew to be fact to arrive at the conclusion. Thanks all for your patience.:thumbsup:

I held off on buying the Feed The Beast fittings until I figured out whether I had my truck back or not. I hope Walking J will still honor his Xmas discount for me as now I'm ultimately headed towards an ATT.:eek:
 
Congrats, it's hard to give advise when we are not there, just our experiences and what we've learned here. I now know one more thing thanks to you:thumbsup:
 
Good for you, BigT ... way to be persistent!

I try to stay quiet on things I know bugger-all about, and CPS is one of 'em... Like Leo, I now know a bunch more, thanks to you taking the time to talk everything out and to your posting pictures!
 
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JiFaire said:
Good for you, BigT ... way to be persistent!

I try to stay quiet on things I know bugger-all about, and CPS is one of 'em... Like Leo, I not know a bunch more, thanks to you taking the time to talk everything out and to your posting pictures!
Click to expand...

I noticed that you did not jump in and it was frustrating me, but now you've explained why.:thumbsup:

And yes I totally understand that some of this is very hard to advise on when you're not there. Many times I was scratching my head thinking these guys aren't looking at the same thing I am. They're not describing in a language I understand. It was that realization that kept me coming back, explaining, re-setting the thread, etc. I tried really hard not to tear into anyone out of fear that I would lose their input permanently, which probably meant that I would not get my truck back. I put it down, sat on it, went to work, thought about it and re-thought about it. Yesterday I spent most of the day studying threads and searching here for more. Then I found that thread where the guy was describing exactly what I was experience and it was on a freshly rebuilt engine. There was also another thread by Matuva (I need a road trip to New Caledonia) that I studied many times about a month ago as the symptoms were very similar to mine. Finally, I just refused to believe that certain items had gone bad when they were perfectly fine before I started this job and I had not touched them. I did know that I pulled the CPS and the other threads helped me to zero in on this. I am happy that my painful experience did lead to all of us learning something new and simple, but very critical. I guess I need to file this under "just because it fits, doesn't mean you should insert it."

I guess Santa saw that I've been a good boy, as here's the snapshot after Timing Set and TDC Learn:

Snapshot created 12/27/2009 2:15:30 PM
__________________________________________________________________
ENGINE SENSORS
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
Engine run time: 00:01:51
Boost pressure (MAP): 14.6 PSI
Desired EGR: 15.23 PSI
Desired idle: 562 RPM
EGR pressure: 14.58 PSI
EGR duty cycle: 0 %
Engine coolant temp: 186.4 F°
Engine speed: 562 RPM
Glow plug relay feedback: 0.1 Volts
Glow plug voltage: 0.1 Volts
Ignition voltage: 13.4 Volts
Wastegate duty cycle: 67.2 %

__________________________________________________________________
INFORMATION SENSORS
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
PCM Calibration ID: 6885
Current DTCs: 0
Accel. ped. pos. 1: 0.71 Volts
Accel. ped. pos. 2: 4.29 Volts
Accel. ped. pos. 3: 4.02 Volts
Barometric pressure (BARO): 13.72 PSI
Battery voltage: 13.5 Volts
Fuel temperature: 98.2 F°
Intake air temp: 87.6 F°
Throttle position: 0 %
Turbo boost (Calculated): 0.88 PSI
Voltage reference sensor: 1.3 Volts

__________________________________________________________________
INJECTION PUMP SENSORS
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
Actual injection pump timing: 30.89 Deg °
Cam reference missed: 0 Counts
Crank reference missed: 0 Counts
Fuel calibration: 115 Counts
Fuel rate: 9.06 mm³
Fuel rate - Cruise: 0 mm³
Fuel rate - Idle: 9.06 mm³
Fuel rate - Maximum transient: 35.62 mm³
Fuel rate - Throttle requested: 0 mm³
Injection pulse width: 1.98 ms
Injection timing - Measured: 8.7 Deg °
Injection timing - Desired: 8.6 Deg °
TDC offset: -1.94 Deg °

__________________________________________________________________
TRANSMISSION SENSORS
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
3-2 PWM solenoid duty cycle: 0 %
Cruise target speed: 0 MPH
Cruise speed error: 0 MPH
Current gear of transmission: 1 Gear
Current torque signal pressure: 25 PSI
Current transmission ratio: 1:4 Ratio
Error between desired and actual shift times for latest 1-2 upshift: 0 Sec
Error between desired and actual shift times for latest 2-3 upshift: 0 Sec
Force motor (PCS) - Duty cycle: 43.4 %
Force motor (PCS) - Feedback current: 0.82 Amps
Force motor (PCS) - Reference current: 0.82 Amps
Time of latest 1-2 upshift: 0 Sec
Time of latest 2-3 upshift: 0 Sec
TCC PWM solenoid duty cycle: 0 %
TCC slippage: 10 RPM
Transmission input speed: 548 RPM
Transmission output speed: 0 RPM
Transmission temperature: 153 F°
Turbine speed: 548 RPM
Vehicle speed: 0 MPH
 
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Been in a PM session on this one.

Thats what I said. How the hell did it get turned.

Hold down bracket on the CPS must have come loose.

Never seen that happen.

I have ripped a few CPS's out to replace them and after I got done they were in Pieces.

Definately makes sense now though.

Me thinks a new sensor is in Order.

No need to redo the time set, just replace the sensor.


Missy
 
Well my son pulled the CPS out and the first time I saw it, the hold down bracket was separate from the sensor. I just assumed that's the way it came.

Look at it this way, thank god my first time was NOT with a hermaphrodite.:eek:):h

How about an attaboy for hitting that -1.94 TDCO?
 
Big T said:
And that was it!

I pulled the CPS, flipped it 180 and reinstalled. Engine immediately fired up with very little smoke and only for the first second or two. Haven't timed it yet, but it sounds like normal. My marks on the IP are lined up just where they were when I started the original tear down. The thing sounds so close to normal that my dog (English Springer) jumped in through the driver side window with the door closed, thinking we must be going somewhere. Truck is warming up now.

I will post up pics of the CPS as it has marks on it that are definitely position sensitive. The marks need to be towards the radiator. Here's the photo:

IMG_0865.jpg


Notice the two dots. It needs to be installed with those vertically aligned and towards the radiator. There are also two metal strips lined up horizontally on the face of the CPS. One is thicker than the other. These are obviously the sensors and with their size being different, they obviously do different things and their order is important.

Thanks for all the input. It took just a little reading between the lines of all the input here and in that other thread to figure this out. I guess I'm my own trouble shooter. The key was that other thread where the guy was having the exact same problems. Also the realization that I never pulled the CPS the second time I had the cover off. Finally, a big thanks to my wife an her thin arms which came in handy when reinstalling the CPS.
Click to expand...
I wish now i had looked at my spare CPS before i posted the position of the flats,it may have made me aware of the magnets on the face being different sized. Actually i had the magnet flats in mind,not the body flats.

good thing you found that hickup though, it would've drove me bananas too.:mad2:
 
I guess the sensor bracket being busted off was the clue we missed. And now we know of another way to make things work, but not work. Did it seem natural to be separated, something we need to look out for?
 
buddy said:
I guess the sensor bracket being busted off was the clue we missed. And now we know of another way to make things work, but not work. Did it seem natural to be separated, something we need to look out for?
Click to expand...

Yes when the first time I saw it the bracket was separated from the sensor, so the assumption was that was the natural condition.

BTW fired it up again while outside manning the barbecue. Engine was completely cold. As cold as it can get at 52 F. It fired up immediately with no smoke AND I can't hear any difference in sound at -1.94 TDCO. I guess it's different when the temps are sub zero?

Next up: injectors and glow plugs.
 
Big T said:
Yes when the first time I saw it the bracket was separated from the sensor, so the assumption was that was the natural condition.

BTW fired it up again while outside manning the barbecue. Engine was completely cold. As cold as it can get at 52 F. It fired up immediately with no smoke AND I can't hear any difference in sound at -1.94 TDCO. I guess it's different when the temps are sub zero?

Next up: injectors and glow plugs.
Click to expand...

See if you can stump us again! :grouphug:
 
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