97' Silverado timing issue
thecackster
01-18-2011, 02:54 PM
Okay lets just say that I'm fed up with my truck at this point. 97 Silverado 350.
The Story:
I parked it about 4 months ago due to a gasket leaking antifreeze. Dad and a friend decided to help me out so I didn't have to take it in. We pull both heads, dipped them, and clean them. Replace the lifters that seem worn, replace all other gaskets for valve covers ect...Also replaced some of the rocker arms. but in the process Dad gets pneumonia and is down for about a month. It remained covered for this time under the car port, but was very very cold sub zero temps. Now that everything has been put back together we had a hell of a time getting it to start in the first place, once we seemed to get it started it was rough but it ran. Took the distributer out to try and get it right on, and hasn't started since.
I have read in the book and from many online places that TDC and #1 but I saw on another forum that it should be on #8... Can someone plz help me out. We hooked it up to a computer and the code was cam shaft positioning error or something of the sort, so I got a new sensor.... Not sure if this is the case.
The Story:
I parked it about 4 months ago due to a gasket leaking antifreeze. Dad and a friend decided to help me out so I didn't have to take it in. We pull both heads, dipped them, and clean them. Replace the lifters that seem worn, replace all other gaskets for valve covers ect...Also replaced some of the rocker arms. but in the process Dad gets pneumonia and is down for about a month. It remained covered for this time under the car port, but was very very cold sub zero temps. Now that everything has been put back together we had a hell of a time getting it to start in the first place, once we seemed to get it started it was rough but it ran. Took the distributer out to try and get it right on, and hasn't started since.
I have read in the book and from many online places that TDC and #1 but I saw on another forum that it should be on #8... Can someone plz help me out. We hooked it up to a computer and the code was cam shaft positioning error or something of the sort, so I got a new sensor.... Not sure if this is the case.
777stickman
01-18-2011, 04:52 PM
With #1 piston at TDC on compression stroke the rotor needs to point to the #8 on the dist housing not to the #1 plug wire. Once that is set and the motor is running you'll need to set the base timing (cam retard or cam offset) with a high end scan tool that can access these settings. Base timing needs to be 0 +/- 2 degs at 1500 to 2000 rpm.
Hope this helps get you back on track.
Hope this helps get you back on track.
thecackster
01-18-2011, 05:35 PM
With #1 piston at TDC on compression stroke the rotor needs to point to the #8 on the dist housing not to the #1 plug wire. Once that is set and the motor is running you'll need to set the base timing (cam retard or cam offset) with a high end scan tool that can access these settings. Base timing needs to be 0 +/- 2 degs at 1500 to 2000 rpm.
Hope this helps get you back on track.
Thanks mate! I hope I can get it now! :D
Hope this helps get you back on track.
Thanks mate! I hope I can get it now! :D
MT-2500
01-19-2011, 06:48 AM
Okay lets just say that I'm fed up with my truck at this point. 97 Silverado 350.
The Story:
I parked it about 4 months ago due to a gasket leaking antifreeze. Dad and a friend decided to help me out so I didn't have to take it in. We pull both heads, dipped them, and clean them. Replace the lifters that seem worn, replace all other gaskets for valve covers ect...Also replaced some of the rocker arms. but in the process Dad gets pneumonia and is down for about a month. It remained covered for this time under the car port, but was very very cold sub zero temps. Now that everything has been put back together we had a hell of a time getting it to start in the first place, once we seemed to get it started it was rough but it ran. Took the distributer out to try and get it right on, and hasn't started since.
I have read in the book and from many online places that TDC and #1 but I saw on another forum that it should be on #8... Can someone plz help me out. We hooked it up to a computer and the code was cam shaft positioning error or something of the sort, so I got a new sensor.... Not sure if this is the case.
http://files.automotiveforums.com/gallery/showphoto.php?photo=51302
As 777stickman said.
And remember there is 2 TDC one compression and one exhaust.
Make sure it is on TDC compression.
You can remove no 1 spark plug and hold finger over hole to feel for compression stroke.
The Story:
I parked it about 4 months ago due to a gasket leaking antifreeze. Dad and a friend decided to help me out so I didn't have to take it in. We pull both heads, dipped them, and clean them. Replace the lifters that seem worn, replace all other gaskets for valve covers ect...Also replaced some of the rocker arms. but in the process Dad gets pneumonia and is down for about a month. It remained covered for this time under the car port, but was very very cold sub zero temps. Now that everything has been put back together we had a hell of a time getting it to start in the first place, once we seemed to get it started it was rough but it ran. Took the distributer out to try and get it right on, and hasn't started since.
I have read in the book and from many online places that TDC and #1 but I saw on another forum that it should be on #8... Can someone plz help me out. We hooked it up to a computer and the code was cam shaft positioning error or something of the sort, so I got a new sensor.... Not sure if this is the case.
http://files.automotiveforums.com/gallery/showphoto.php?photo=51302
As 777stickman said.
And remember there is 2 TDC one compression and one exhaust.
Make sure it is on TDC compression.
You can remove no 1 spark plug and hold finger over hole to feel for compression stroke.
Blue Bowtie
01-19-2011, 07:33 AM
Remember to position the distributor thus:
http://www.wwdsltd.com/files/CKP-CMPPhasing.jpg
A meter will work fine. The scan tool only displays what the sensors and PCM are telling it. You can learn what the PCM is looking at before the PCM knows it by using a meter.
You can try to manually position the crank so that the CKP is triggered, then set the distributor so that the interruptor (half cup) is just starting to cover the CMP. As long as the crank sensor triggers a couple milliseconds before the CMP triggers the PCM will stupidly accept the position as "perfect" #1 firing position. It still times from the crank sensor, so the cam sensor isn't all that critical. It's very similar to the old Ford system in that regard. What sucks is when the distributor was factory assembled so that the rotor position is not optimally aligned with the terminals in the cap when the CMP interruptor signals the cam sensor. I've seen a couple of them so bad that it looked like Bosch made them.
http://www.wwdsltd.com/files/CKP-CMPPhasing.jpg
A meter will work fine. The scan tool only displays what the sensors and PCM are telling it. You can learn what the PCM is looking at before the PCM knows it by using a meter.
You can try to manually position the crank so that the CKP is triggered, then set the distributor so that the interruptor (half cup) is just starting to cover the CMP. As long as the crank sensor triggers a couple milliseconds before the CMP triggers the PCM will stupidly accept the position as "perfect" #1 firing position. It still times from the crank sensor, so the cam sensor isn't all that critical. It's very similar to the old Ford system in that regard. What sucks is when the distributor was factory assembled so that the rotor position is not optimally aligned with the terminals in the cap when the CMP interruptor signals the cam sensor. I've seen a couple of them so bad that it looked like Bosch made them.
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