Acesneights1
New Member
I'm at -1.50. I can't tell ya how i got there. Just got lucky.
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Q&A for DS4 timing thread
- Thread starter gmctd
- Start date
NVW
Well-Known Member
You had mentioned TDG's bump was in effect similar to a 5* advance. As I was unable to achieve a TDCO of -1.5* until I debumped it I assumed it was like setting the timing to far in advance.
I thought it would be of interest.
Leo
Acesneights1
New Member
OK so you are saying you had done the Optic Bump, and then because of that could not achieve -1.50 TDCO ? Until you set the OS back to normal ?
Just for the uninformed you won't find TDG in the acronym file.
TDG=Texas Diesel Guy from the old site.
Just for the uninformed you won't find TDG in the acronym file.
TDG=Texas Diesel Guy from the old site.
OK, NVW, just wanted to make sure we're on the same page - do the Bump, or advance the IP with TDCO - not both, they're not compatible because they do the same thing, with TDCO having the edge
And low fuelrate is the symptom for too much bump
Do the Bump and let it ride - PCM will auto adjust over time, then just check your timing
Or, de-bump the bump, do IP adjust\TIMESET\TDCO LEARN, and be done with it
And low fuelrate is the symptom for too much bump
Do the Bump and let it ride - PCM will auto adjust over time, then just check your timing
Or, de-bump the bump, do IP adjust\TIMESET\TDCO LEARN, and be done with it
NVW
Well-Known Member
No, either OB had been done by PO or it was just a quirk of the IP to have an idle fuel rate of 5mm3. The IP position had been moved by PO. I'm basing that on the fact that there were scribe marks.
And yes I could not get -1.5* TDCO until I moved the OS to achieve an idle fuel rate of 6.5mm3.
Leo
Edit: This is in response to Aces post
And yes I could not get -1.5* TDCO until I moved the OS to achieve an idle fuel rate of 6.5mm3.
Leo
Edit: This is in response to Aces post
Brooklyn Tow
9 11 Never Forget
Nothing like a good "Bump!" :mikelsheep: - BTW, did you ever bump your truck, way back when?
For anyone interested, I believe you can still access all those threads/posts at the old site if that kind of stuff makes your dipstick wiggle....Thats about as far as you can go back for free, to read "6.5 History 101" :deal:......You'll need a paid membership at the "Page" for anything before that.
lcoot:Did not even consider the OS Bump, because I had determined the consequences that would result with a mod that affected operation over the entire rpm range, idle to fwot - as I stated, there are some roads here where even the factory sensitivity is too great
Brooklyn Tow
9 11 Never Forget
Geez, like pulling teeth .......Just trying to squeeze out the why.
enquiring minds would like to know.......what you have forgotten, Sir :werd:
Brooklyn Tow
9 11 Never Forget
Couldn't roll like that, thats for sure........and, "wala" the TDCO "perfomance values" were born.
and thats the why.
Just so we're all on the same page, here, I didn't invent advanced DS4 timing and TDCO - that was being done with much success on the Diesel Page when I signed on back in ought zero - problem was, noone could explain it evenly remotely satisfactorily
"Ok, let's advance the IP 5* for more performance, then let PCM calculate a negative number to offset that advance by -1.5*"
Say what?
Well, then, let's add a 'nuther +1.5* and advance the IP 6.5*, so we'll wind up with our +5*. Ha! - ain't no computer gonna slow me up
"Cain't do dat - PCM will set an almost unclearable TDCO DTC if you go too far"
Say what?
"Yep, and the engine prolly won't ever start again till you clear it........if you can clear it"
Say whaaaaaaat?? What kinda chicken sh*t outfit is this, anyway?
No, my friends, I didn't invent it - my travails were in finding a viable explanation in a congressionally-mandated explanationless world - TDG's explanation of the OS Bump, which was also being done successfully, finally closed that door
"Ok, let's advance the IP 5* for more performance, then let PCM calculate a negative number to offset that advance by -1.5*"
Say what?
Well, then, let's add a 'nuther +1.5* and advance the IP 6.5*, so we'll wind up with our +5*. Ha! - ain't no computer gonna slow me up
"Cain't do dat - PCM will set an almost unclearable TDCO DTC if you go too far"
Say what?
"Yep, and the engine prolly won't ever start again till you clear it........if you can clear it"
Say whaaaaaaat?? What kinda chicken sh*t outfit is this, anyway?
No, my friends, I didn't invent it - my travails were in finding a viable explanation in a congressionally-mandated explanationless world - TDG's explanation of the OS Bump, which was also being done successfully, finally closed that door
Last edited:
Brooklyn Tow
9 11 Never Forget
Right, You did the hard part.......the "why"
On Edit: Should of said, TDCO performance values were logiclly explained.
Better?
Last edited:
Brooklyn Tow
9 11 Never Forget
btt
DieselAmateur
She ain't revved 'til the rods are thrown...
In GMTDScan Tech, my actual and desired read around 11* with the truck idling. TDCO reads an even 0*. I haven't tried to command timeset or TDCO. Are these ok numbers to start out with?
Paveltolz
Доверяй, но проверяй
I'm mudwrestling with the IP timing and TDC Learn functions right now (thanks again for the loan of your TECHII AK Diesel), still losing the wrestling match. My truck is OBD II and it looks like the procedure is about the same for the 1995 OBD I.
IP timing set first, TDC Learn second.
I hope I write the rest of this correctly. No worries, someone will chime in....that's what friends are for.
My IP Times (Actual and Adjusted) read in the 11s or whatever even after I did the IP Time Set and got it into the 3.5* desired range. When you activate "Time Set" by hitting the 'On' function, the Actual number is supposed to drop to 0.00. During the IP timeset function, you need to watch the readings as they will fluctuate... changes by a couple of 10ths in about a one degree span (eg. 3.0, 3.3, 3,7, 4.0 etc.). If it the readings during the "Learn" command are above 3.5* then you need to move the pump towards the passenger side fender. Rinse and repeat (I was at it over 9 times this last go round). Once your readings are fluctuating between 3 and 4 degrees, then you can set the IP Time. While its bouncing around between 3 & 4* get ready and hit the command 'off' button as soon as the readings hit 3.5* (you gotta have gamer reflexes or it will be a multi attempt effort). Note, unlike the TDC Learn function, IP Timing set procedure won't end until you hit 'off.'
Once you get your IP timing where you wants it, then you can go to the TDC Learn function for more fun.
Starting value will read "0.00" and when you hit the 'On' for starting the learn process, the engine will cough and sound like it wants to die, then steady up a bit and chug a little for about 20 seconds until it is through (Command State: None). Then you'll have your TDC Offset Value.
I finally got the IP set to 3.5* (the actual and desired reads 11ish once leaving the the Time Set screen) and the TDC went to -1.94 after being stuck on stupid at -2.46 for over a week of different tunes and IP position changes. Unfortunately, the truck is running worse with the new IP and so I have other issues apparently.
IP timing set first, TDC Learn second.
I hope I write the rest of this correctly. No worries, someone will chime in....that's what friends are for.
My IP Times (Actual and Adjusted) read in the 11s or whatever even after I did the IP Time Set and got it into the 3.5* desired range. When you activate "Time Set" by hitting the 'On' function, the Actual number is supposed to drop to 0.00. During the IP timeset function, you need to watch the readings as they will fluctuate... changes by a couple of 10ths in about a one degree span (eg. 3.0, 3.3, 3,7, 4.0 etc.). If it the readings during the "Learn" command are above 3.5* then you need to move the pump towards the passenger side fender. Rinse and repeat (I was at it over 9 times this last go round). Once your readings are fluctuating between 3 and 4 degrees, then you can set the IP Time. While its bouncing around between 3 & 4* get ready and hit the command 'off' button as soon as the readings hit 3.5* (you gotta have gamer reflexes or it will be a multi attempt effort). Note, unlike the TDC Learn function, IP Timing set procedure won't end until you hit 'off.'
Once you get your IP timing where you wants it, then you can go to the TDC Learn function for more fun.
Starting value will read "0.00" and when you hit the 'On' for starting the learn process, the engine will cough and sound like it wants to die, then steady up a bit and chug a little for about 20 seconds until it is through (Command State: None). Then you'll have your TDC Offset Value.
I finally got the IP set to 3.5* (the actual and desired reads 11ish once leaving the the Time Set screen) and the TDC went to -1.94 after being stuck on stupid at -2.46 for over a week of different tunes and IP position changes. Unfortunately, the truck is running worse with the new IP and so I have other issues apparently.
MrMarty51
Well-Known Member
I`m not sure about all this timing stuff. I`m just reading and giving You a bump back to the top so maybe someone with more knowledge than I can reply.
DieselAmateur
She ain't revved 'til the rods are thrown...
Thanks for sharing your experice @Paveltolz . I haven't had time to mess with my IP timing yet, as I need the truck daily for work and the last thing I need to do is have it be not drive-able when I have to tow my mini excavator to a job site.
When you move your IP, do you do so by hand or by using the pump rotating tool? I've seen folks write about just "bumping" the IP from side to side, while others point out the need for an extremely overpriced piece of metal. I already spent the $100 on the curvy IP wrench set. I saw another suggestion to just put 3/8" bolts in the 2 holes and use a pry bar to move the IP that way, which I'm going to do as the bolts are a lot cheaper! I know you can make your own tool as well for cheap, I just don't have the time. Notice a theme here?
When I work up the courage, I'll try your method and report back. I also thought I read somewhere way back when that you want base/ actual timing to be around 11*, something about the most advance you can get is 8.5*, and this advance plus the default desired 3.5* giving you a reading somewhere in the 11* range.
All of this will be good to learn, and is giving me the motivation to get all the rest of my cart together before getting connected to the proverbial DB2 horse. I've got the intercooler parts on my living room floor and enough cash to upgrade to a Hybrid Holset, which will then allow me to go mechanical and get some of the power currently left on the table. Then I'll start another thread asking for help on timing the DB2 haha
When you move your IP, do you do so by hand or by using the pump rotating tool? I've seen folks write about just "bumping" the IP from side to side, while others point out the need for an extremely overpriced piece of metal. I already spent the $100 on the curvy IP wrench set. I saw another suggestion to just put 3/8" bolts in the 2 holes and use a pry bar to move the IP that way, which I'm going to do as the bolts are a lot cheaper! I know you can make your own tool as well for cheap, I just don't have the time. Notice a theme here?
When I work up the courage, I'll try your method and report back. I also thought I read somewhere way back when that you want base/ actual timing to be around 11*, something about the most advance you can get is 8.5*, and this advance plus the default desired 3.5* giving you a reading somewhere in the 11* range.
All of this will be good to learn, and is giving me the motivation to get all the rest of my cart together before getting connected to the proverbial DB2 horse. I've got the intercooler parts on my living room floor and enough cash to upgrade to a Hybrid Holset, which will then allow me to go mechanical and get some of the power currently left on the table. Then I'll start another thread asking for help on timing the DB2 haha
Paveltolz
Доверяй, но проверяй
I used the 3/8" bolts, about one inch long with a nut threaded all the way up to the head. That allowed greater control without running into clearance issues as well as stabilizing the bolt as the nut stops the bolt from 'drooping' and thus, falling out. If you find you need to rotate the IP to the passenger side, only one one bolt in the bottom hole is really needed.
Just use the top nut to secure the pump from moving as you seek the magical 3.5* IP time set. It will hold. Snug up the bottom two until ready to lock 'er down.
I saw the actual and desired time readings (prior to the Time Set Polka) drop to about 9.5* Actual with desired sometimes following but, mostly hanging a coupe degree's higher as I moved the pump to the passenger side. As you get closer to the sweet spot, you'll see the Time Set function start to respond to the 'On' command. Too far to the driver's side and it will kill the motor. Likewise, too far to the passenger side and the TDC learn function will kill the motor when activated. For my efforts, it was a delicate balance which is why when you get close to 'bingo' your pump movements need to be measured in hair widths. Not joking.
To aid my efforts, I cleaned the surface of the IP and t Timing Cover. I then placed 1/4" strips of painter's tape on both the IP and the Timing Cover. The tape was pre-marked. IP's had a single, narrow, reference line and the Timing Cover's had a long line with 1 mm (ish) reference ticks. Helped as the loosening of nut between adjustments will cause the IP to self adjust given the springlike tension of the injector lines making it move back. "Pictures or it didn't happen...."
Best wishes for success. It sounds tiresome but, with healthy system (unlike mine) it will be a lot easier than it sounds.
Just use the top nut to secure the pump from moving as you seek the magical 3.5* IP time set. It will hold. Snug up the bottom two until ready to lock 'er down.
I saw the actual and desired time readings (prior to the Time Set Polka) drop to about 9.5* Actual with desired sometimes following but, mostly hanging a coupe degree's higher as I moved the pump to the passenger side. As you get closer to the sweet spot, you'll see the Time Set function start to respond to the 'On' command. Too far to the driver's side and it will kill the motor. Likewise, too far to the passenger side and the TDC learn function will kill the motor when activated. For my efforts, it was a delicate balance which is why when you get close to 'bingo' your pump movements need to be measured in hair widths. Not joking.
To aid my efforts, I cleaned the surface of the IP and t Timing Cover. I then placed 1/4" strips of painter's tape on both the IP and the Timing Cover. The tape was pre-marked. IP's had a single, narrow, reference line and the Timing Cover's had a long line with 1 mm (ish) reference ticks. Helped as the loosening of nut between adjustments will cause the IP to self adjust given the springlike tension of the injector lines making it move back. "Pictures or it didn't happen...."
Best wishes for success. It sounds tiresome but, with healthy system (unlike mine) it will be a lot easier than it sounds.
Turbine Doc
Just Another Diesel Guy
One thing missing from this Paul is operating temp being 170+ or learn command will not "take" much of this is I posted on OBD-II is very similar to OBD-I https://www.thetruckstop.us/forum/threads/time-setting-obd-ii-with-mt2500.37148/ biggest departure OBD-I to best of my memory does not have ko/ko with APP to floor "learn command" capability and scan tool or software is required for those.