Well, sorry about the delays in updates on this one but it was not good so had to abandon the truck for a while...been drive the old Chevy truck which is great...simple TBI system and runs great. Anyway back to the update on the 2000 Yukon.
Tranny shop did a diagnostics on it and reported it does have a sticky TCC but that is for sure not causing the problem. They even noted that the sticky TCC is actually probably not even worth really messing with at this point until the other issue is resolved. Did have them service it while it was there. BTW, after clearing the code and driving again for a while the TCC code has not returned so might have been some junk in it so the service might have helped that issue.
As an update the fuel pressure on the truck was sitting about 45PSI which from various inputs at various sites was lower than the lowest posts. BTW, not sure anyone really nows the actual pressures that should be read with the regulator disabled but again this was lower than any posts found. So, went for it...replaced the fuel pump. NO JOY...the problem continues.
I am really beginning to wonder about a timing chain issue now. Since this occurs during tip in on acceleration, right as you would normally see a timing advance, I wonder if some how the timing chain is sloppy, slipped, something. I am out of ideas as the only sensors left to replace are the temperature sensors (oil and water), and the O2s. After that I am out of sensors and have all new ones on the truck. I guess pickup the truck and throw it away next and put a new in its place.
Any ideas are going to be entertained now. has anyone looked at how to verify the timing chain without removal of it on these computer control systems??
Running tests do not show any problems from the dealer diagnositcs so kind of strange but if it is mechanical this would require a mechanic and not a technician as they are called now.
Ok, I will not go there.
Tranny shop did a diagnostics on it and reported it does have a sticky TCC but that is for sure not causing the problem. They even noted that the sticky TCC is actually probably not even worth really messing with at this point until the other issue is resolved. Did have them service it while it was there. BTW, after clearing the code and driving again for a while the TCC code has not returned so might have been some junk in it so the service might have helped that issue.
As an update the fuel pressure on the truck was sitting about 45PSI which from various inputs at various sites was lower than the lowest posts. BTW, not sure anyone really nows the actual pressures that should be read with the regulator disabled but again this was lower than any posts found. So, went for it...replaced the fuel pump. NO JOY...the problem continues.
I am really beginning to wonder about a timing chain issue now. Since this occurs during tip in on acceleration, right as you would normally see a timing advance, I wonder if some how the timing chain is sloppy, slipped, something. I am out of ideas as the only sensors left to replace are the temperature sensors (oil and water), and the O2s. After that I am out of sensors and have all new ones on the truck. I guess pickup the truck and throw it away next and put a new in its place.
Any ideas are going to be entertained now. has anyone looked at how to verify the timing chain without removal of it on these computer control systems??
Running tests do not show any problems from the dealer diagnositcs so kind of strange but if it is mechanical this would require a mechanic and not a technician as they are called now.
Ok, I will not go there.
