tireguy
New Member
Hey guys what should the timing be set at when doing a time set, i just got done installing a new ip want to get it right. Thanks
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Time set 1996 K1500
- Thread starter tireguy
- Start date
ak diesel driver
6.5 driver
factory TDCO is -.35 thru -.75 max perf being -1.94 alot of people think -1.94 is too rattley and run it slightly lower
tireguy
New Member
i dont know if its nessasary as it runs good, no codes and a OTC scanner says its set at -1.8 but the gm guy says he wont charge anything so long as it goes well and doesnt take a lot of time so i figured why not!! It just seems like it would be good with a new ip??? dont know
ak diesel driver
6.5 driver
It's reading the old TDCO number stored in the pcm.
tireguy
New Member
well i had the time set done it seems to run nicer snappier but starts a little harder?? It may be just me maybe im watching it a bit to close and just being critical dont know. i hooked OTC scanner to it when my wife brought it home and it shows a setting of 1.8 it has to mean -1.8 right.
ak diesel driver
6.5 driver
no it does not you need to turn the IP to the drivers side a couple of mms and retry.
buddy
Active Member
It likely does start harder with that TDCO setting. It can be positive or negative, and you want negative. I would turn it about 4-5mm towards driver side and run TDCO learn procedure which is from a scanner or KOKO for OBD2 and check TDCO value again. I would shoot for like -0.88 to -1.35
The computer now knows how to modify timing correctly which means you are likely getting more accurate advance now, more advance than before. But now it knows youre retarded a littl emuch and depending on some factors timing at startup could be a little more advanced for a little harder starting. The OBD2 tunes all seem to have a high idle advance setting.
The computer now knows how to modify timing correctly which means you are likely getting more accurate advance now, more advance than before. But now it knows youre retarded a littl emuch and depending on some factors timing at startup could be a little more advanced for a little harder starting. The OBD2 tunes all seem to have a high idle advance setting.
tireguy
New Member
but if it wash set at 1.8 versus -1.8 it wouldnt run well at all would it?? it is giving gray/white smoke at startup just a puff
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buddy
Active Member
It runs fins at retarded timing, just not as much get up and go, and maybe a little different cold start. It probably idles nice and cruises smooth.
If a trustworthy scanner showed it as +1.8 its not uncommon for them to be running well like that, just not as much pep.
If a trustworthy scanner showed it as +1.8 its not uncommon for them to be running well like that, just not as much pep.
tireguy
New Member
Ok i have an OTC scanner and Bill Heath says it should do a time set. I wint to special test/ diesel tests/ injection timing, and commanded to do its thing. the engine bucked around a little, the des timing and act timing went to 0 for a few seconds but the TDC offset stays the same (i moved the pump to drivers side a mm) so what am i doing wrong
If im showing TDC offset of 1.8 instead of -1.8 other than a power difference what will i see. I took it on a trip a week ago, just the pickup and was pretty disappointed i didnt get better mpg it ran 17.6. It seems a empty half ton pickup should do a little better
ANY ADVICE
If im showing TDC offset of 1.8 instead of -1.8 other than a power difference what will i see. I took it on a trip a week ago, just the pickup and was pretty disappointed i didnt get better mpg it ran 17.6. It seems a empty half ton pickup should do a little better
ANY ADVICE
Chief915
915A Maint Tech
Start off by moving the pump again. Roate the pump until your fuel solenoid is straight up and down, not leaning toward either side. Tighten the top, easiest to get to, IP nut down and run the TDCO again with your scanner. You can leave the other 2 IP nuts loose for now because you will likely need to move the IP again in a few minutes.
Couple things to remember, your coolant temp MUST be higher than 180* F when you try to set TDCO. You CANNOT have any DTC's (trouble codes) in the computer when you try to set TDCO, make sure you clear all current and historical codes first.
Couple things to remember, your coolant temp MUST be higher than 180* F when you try to set TDCO. You CANNOT have any DTC's (trouble codes) in the computer when you try to set TDCO, make sure you clear all current and historical codes first.
tireguy
New Member
will have to try again. i cant find a place on the scanner that will tell what the base timing is although when you go into time set a screen pops up and says it whould be 3.5 degrees and if its not to loosen the pump and try again.
Chief915
915A Maint Tech
You can't change base timing, it is controlled by the ECM and the stepper motor inside the IP. You can rotate the IP all over, the ECM will "adjust" to get the desired base timing.
TDCO is a different animal than base timing, it is what you are "setting" by moving the IP and then commanding TDC Offset on your scanner. You are looking to get a value of -1.23 to -1.50.... you can go to -1.94, but the engine with be more rattly when it's cold.
buddy
Active Member
The "base timing" you actually can change, but most people with OBD2 never see it, unless you have a scanner that does Time Set.
The base timing changes with moving the IP and is directly related to TDCO. The Time Set shows the base timing and it needs to be about 3.5, maybe a bit more while the desired is set to 0. What was the timing value while doing Time Set?
What the PCM controls and you cannot change would be the operating timing, which should be anywhere from 4.5 for EGR vehicles to 12 degrees for 1 tons desired at idle.
Attached I have timing info available on first and second pages that may be helpful.
The base timing changes with moving the IP and is directly related to TDCO. The Time Set shows the base timing and it needs to be about 3.5, maybe a bit more while the desired is set to 0. What was the timing value while doing Time Set?
What the PCM controls and you cannot change would be the operating timing, which should be anywhere from 4.5 for EGR vehicles to 12 degrees for 1 tons desired at idle.
Attached I have timing info available on first and second pages that may be helpful.
Chief915
915A Maint Tech
Not trying to hi-jack the thread.... Just want to make sure we all have a better understanding of these timing related questions.
This is what I was referring to.... Mine always shows 3.5 actual when I command time learn. The TDCO was set to -.35 when I got the truck and even after rotating the IP to change TDCO and once TDCO was set to -1.94, it still shows 3.5 actual during time set. It show's 4.4ish actual at idle with both TDCO settings too.
That's what I am calling "base timing". Maybe I am thinking of the term incorrectly or using the term "base timing" wrong.
I asked the same question as the OP a couple months ago and was told that it can only be changed through a EPROM reprogram..........
http://www.thetruckstop.us/forum/showthread.php?29630-Help-Time-set-and-TDC-learn Post #6, second paragraph
Are we talking about the same thing or am I confused?
Also, just for clarification.... all of this was with my factory chip.... not the chip in my sig.
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buddy
Active Member
Base timing is set by moving the IP and running the timing procedure. Normal operating timing is completely controlled by the PCM as was stated, and only a PCM reprogram can change that. The normal operating timing will not change at all by changing the "base timing", it just changes the TDCO value.
The time set jumps around a lot on mine, so its hard to say what it really is, but kind of an average. It can also be inaccurate until you actually run the TDCO learn, because the TDCO learn needs to be done to get accurate values against the CPS. The time set values can often be different if you just run TDCO learn and run the time set again. This is similar to what you saw with 3.5 in time set, but the base timing you saw during TDCO learn was more like 4 degrees. The difference between -.35 and -1.94 TDCO is actually a very small difference in base timing.
Base timing is the physical lowest timing before the PCM takes over control. Thats why when desired PCM timing is 0 you see what the lowest it can go down to. Normal operating timing is never as low as base timing.
The time set jumps around a lot on mine, so its hard to say what it really is, but kind of an average. It can also be inaccurate until you actually run the TDCO learn, because the TDCO learn needs to be done to get accurate values against the CPS. The time set values can often be different if you just run TDCO learn and run the time set again. This is similar to what you saw with 3.5 in time set, but the base timing you saw during TDCO learn was more like 4 degrees. The difference between -.35 and -1.94 TDCO is actually a very small difference in base timing.
Base timing is the physical lowest timing before the PCM takes over control. Thats why when desired PCM timing is 0 you see what the lowest it can go down to. Normal operating timing is never as low as base timing.
tireguy
New Member
well i tried for awhile with no luck. i guess ill wait for my gm guy to have an opening to time it with a tech 2.
i ran a couple of quarter mile runs and ended up aroung upper 18sec and 76mph, seems kind of slow what do u all think?
also even with high flow injectors i cant get over about 1000 degrees pre turbo. just my random thoughts.
I could never get the scanner (OTC Genisis) to show a base timing value and the TDC offset stayed the same no matter how much i moved the ip and commanded a time set. It acted like it was doing something as it would stumble and the des timing would go to 0 for a few sec. and then pick back up the actual timing would go down between 4 and 7 degrees. but the TDCoffset stayed at 1.8 and never jumped or flickered or anything. By the way the first time around i left the oil line to the turbo off:mad2::mad2: big mess on driveway
i ran a couple of quarter mile runs and ended up aroung upper 18sec and 76mph, seems kind of slow what do u all think?
also even with high flow injectors i cant get over about 1000 degrees pre turbo. just my random thoughts.
I could never get the scanner (OTC Genisis) to show a base timing value and the TDC offset stayed the same no matter how much i moved the ip and commanded a time set. It acted like it was doing something as it would stumble and the des timing would go to 0 for a few sec. and then pick back up the actual timing would go down between 4 and 7 degrees. but the TDCoffset stayed at 1.8 and never jumped or flickered or anything. By the way the first time around i left the oil line to the turbo off:mad2::mad2: big mess on driveway
buddy
Active Member
There is commanding time set, and then there is commanding TDCO learn. So both steps are needed, or you can run the KOKO method to initiate TDCO learn.
tireguy
New Member
i dont understand the KO ko method heard it mentioned here but havnt been able to see a discrption can u explain. so if i understand right i was probably commanding TDCO learn and not time set?
buddy
Active Member
You were likely commanding time set, but the real timing change happens with the TDCO learn. KOKO is key on key off
From the timing thread...
*Do the KOKO procedure (courtesy of member OregonHorseTug)
1.Mash pedal to floor and hold it there
2.Key ON 45 seconds
3.Key OFF
4.Release pedal
5.Wait 30 seconds
6.Turn key and start engine after glow cycle
As engine fires up, engine rpm will increase, engine will hesitate and stumble as PCM determines newly-adjusted IP position, then will smooth out to normal idle after new TDCO value is calculated
From the timing thread...
*Do the KOKO procedure (courtesy of member OregonHorseTug)
1.Mash pedal to floor and hold it there
2.Key ON 45 seconds
3.Key OFF
4.Release pedal
5.Wait 30 seconds
6.Turn key and start engine after glow cycle
As engine fires up, engine rpm will increase, engine will hesitate and stumble as PCM determines newly-adjusted IP position, then will smooth out to normal idle after new TDCO value is calculated