Help on how to time?

[nigeljones]

I have just completed the cooling upgrade and I wish to reset the timing.

Does anyone have a how too and why write up so that my gas mechanic friend who has the scanner can help me do this.

My buddy has access to multiple scanners and I have heard you can only set the timing with a tech 2. He personelly has a Snap On T2500 with a newer cartridge which seems to work the same as a tech 2. ie it has TDC offset learn. Will this device work to set up the timing.

Also why set the timing at -1.94 a realize that any higher will set a code but why not -1.5 for example. Prior to the upgrade the timing was set at
-.61 which I believe the spec range is -0.25 to -0.75.

I am chasing a "White Smoke at Start Up" issue so will the timing have a bearing on it.

Thanks as allways smile.gif

[nigeljones]

Come on Guys Give up the secrets. I need to understand the basic's :(

[Turbine Doc]

Nigel I'm sending a PM to RJ to see if he can put us together I have some info you mite be able to use.

[nigeljones]

Thanks,

I liked your link that showed how you did your IC project. Very informative

[JohnC]

It's really pretty simple when you get right down to it. Connect the scanner and perform TDC offset learn. Read result. If not what you want, adjust the pump slightly and repeat. I'd shoot for -1.5 to -1.94. Adjust the pump no more than a mm or so. a very little goes a long way. Bigger negative numbers (huh?) are more advanced.

[Davis]

Hey,The procedure is pretty easy with a Tech 2. More-Power (Jim) sent me the instructions several years ago. I personally have a Snap On MT2500 scanner and it will do the Time set on a 1996 and newer but the values are not the same as a Tech 2 . For example on my 2000 p/u a Tech 2 showed the TD offset as -.63 from the factory and the snap on scanner showed it as a -4.2 so I called Snap On`s tech line and said they created their own values and it was not an issue for them.The Snap On scanner will not even show the Time Set option for a 1994 or 1995 or at least mine will not.Good luck. I have my 1994`s TD offset on -1.76 and have not had any problems. Good luck . Davis

[GMC Hauler]

You can set the TDC offset yourself and read it with a couple of laptop code readers. Do you have access to the factory service manuals? They describe how to set TDC offset.

Here is a good link to describe why and where to set TDC offset: Click here. (http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=1;t=007093)

Here is a link to tell you how to get the PCM to relearn a new TDC offset: Click Here. (http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=1;t=005498)

Here are instructions on how to rotate the injection pump: Click Here. (http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=1;t=007371)

Here are the part numbers for the pump turning wrenches: Click here. (http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=1;t=006436)

Note that the pump turning tool is no longer available, and these two wrenches from snap on will cost $100. You may be able to use other wrenches, make your own, or get them cheaper somewhere else.

Here is a laptop tool that I personally use that can allow you to see TDC offset, and perform the "command time" procedure: Click here. (http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=1;t=007871)

Hope this helps.

[Turbine Doc]

Originally posted by Davis:
Hey,The procedure is pretty easy with a Tech 2. More-Power (Jim) sent me the instructions several years ago. I personally have a Snap On MT2500 scanner and it will do the Time set on a 1996 and newer but the values are not the same as a Tech 2 . For example on my 2000 p/u a Tech 2 showed the TD offset as -.63 from the factory and the snap on scanner showed it as a -4.2 so I called Snap On`s tech line and said they created their own values and it was not an issue for them.The Snap On scanner will not even show the Time Set option for a 1994 or 1995 or at least mine will not.Good luck. I have my 1994`s TD offset on -1.76 and have not had any problems. Good luck . Davis Properly timed MT2500 for -1.94 real T2 offset value is -5.4 on MT2500 struggled with this for a while myself, Snap On blew me off as well.

Both GMCTD and I were thrown for a loop as by his T2 I was dead on vs. my MT2500, and we could not understand why a -4.8 reading on MT2500 the truck is even running at all, -4.2 Snap On reading is in ballpark of -.25 to -.76 factory stock setting

[nigeljones]

Thanks a bunch :D

I have in the past searched for this info but obviously did not go back far enough. Is there a place on the site that could house FAQ. Just a thought

What does the pump adjust tool look like?

I assume you need it as the engine will be hot and you can be more the ip more accuratly rather than a using a gloved hand.

Again Thanks smile.gif

[Turbine Doc]

Originally posted by GMC Hauler:
You can set the TDC offset yourself and read it with a couple of laptop code readers. Do you have access to the factory service manuals? They describe how to set TDC offset.

Here is a laptop tool that I personally use that can allow you to see TDC offset, and perform the "command time" procedure: Click here. (http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=1;t=007871)

Hope this helps. GMCH is this AE tool bi-directional yet last time I talked to them it was a hi dollar reader, smart tool looked promising, but I already have 1 hi dollar reader with limited bidirectional use in my MT2500. They were supposed to be adding some bi-directional functionality model due out Feb/March this year.

Your AE laptop tool have TDC offset command or did you use KO/KO method to initiate the TDC learn.

[Turbine Doc]

Originally posted by nigeljones:
Thanks a bunch :D

I have in the past searched for this info but obviously did not go back far enough. Is there a place on the site that could house FAQ. Just a thought

What does the pump adjust tool look like?

I assume you need it as the engine will be hot and you can be more the ip more accuratly rather than a using a gloved hand.

Again Thanks smile.gif Hey don't feel so bad some of those posts included some of mine, I knew I had written something on it in days gone by & I could not find them either.

[GMC Hauler]

I have never seen the pump turning tool, but I understand that it connects to the two holes in the pump flange, and allows for easy turning of the pump. You can do this by hand, but is difficult. If someone would post pictures and dimensions of the tool, we could fabricate our own. :D

Nijel, We have all had dificulty searching for stuff on this board. I know I sometimes spend lots of time trying to remember where i saw that one nugget of knowledge. I spent a little time and threw that together for you, and future members. This one is a common question, and I searched for many hours to learn what I posted above.

The AutoEnginuity scan tool can read TDC offset, but can perform the command time procedure. I use the accelerator pedal position trick to relearn TDC. Is there a command in your tool that clears and allows TDC to relearn while the engine is running? If you have any more questions about the tool, click here. (http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=1;t=007871) I update this thread as I get new information. I have somehow become the beta tester.

The AE tool is about $300.

[nigeljones]

Guys,

The info you have all supplied has been fantastic.

I have had to order the wrenches so that will take a while. I saw some cheap wrenches in JC Whitney the Obstruction wrench set for $10 and a Boxed end S wrench set for $10 I'm hoping there as large as the = Snap on wrenches and do the job. I will let you know if they are.

Looking at the pump again last night it seems easy to make a IP adjust tool using a flat bar as a handle with two pins coming out of the side to locate in the two holes in the IP.

With the input from your selves and this site I have a new found confidence about my truck.

Thanks :D

[Shad]

Hows the smokey starts? Did the gears and chain help? Mine still smokes some but I think I am going to swap the chain and gears soon with 147,000 miles.

[nigeljones]

Shad,

My email address is nigeljonesmied@aol.com if you would like to contact me off line I would like to compare notes. Seems like we have similar problems.

Hang on for a while replacing the chain until I get mine timed. As soon as I get the wrenches I will be doing that right away and update the page.

Also if you replace the chain consider the water pump upgrade. That I was pleased with.

She still smokes but the timing is at 0 deg and it's a little harder to start when warm. I plan on setting the timing to -1.50.

The chain at 153000 miles was still in spec, sloppier than the new one though.

It's funny that just after I replaced the my chain,than MP put's out the discussion thread update on DSG gears. Which then when you read the input from everyone else it's like DSG Gears are the cure all, the magic bullet. If it garanteed the fix I would have replaced the chain with the gears in heart beat. But at the back of my mind the IP might be next in the quest for no smoke at start up and that creates further cost. :(

Did you say that you replaced your IP already to eliminate the smoke?

[Shad]

Yes it still smokes some. However I noticed since it warmed up outside it has been less. Another thing is that if I put the transmission in drive right away and wait the engine imediatly stops smoking. ???? I don't get it, Unless the shop was right and said a couple of cylinders were in the 360's are causing the problems. The timing is set right so at this point I am going to DRIVE IT!! untill something changes. Since the new pump in febuary and new injectors in march the truck runs great warm. I got 21 mpg on 450 mile trip recently of coarse running below 70 mph. Maybe I am expecting too much out of a truck with 150K miles???

[nigeljones]

Gentlemen,

I have tried and tried and tied some more to get my timing over -0.86 but I can't get it to go any further. :mad: I've moved the pump probabaly a least 4mm which seems alot and I could be at the end of the adjustment slots. :confused:

In one of my try's I rotated the pump to the other end of the slots, hoping to get more travel. Then I started the procedure all over again but with no improvement.

I am using a MT2500 Snap-On scanner I also through a code 1214 which is about the timing out of adjustment at the -0.86 mark.

What's do you thinks is going on?

I think I can get access to a Tech 2.

If so do you have to move the pump as with procedure for the Snap-On scanner?

Does anyone have the procedure for the Tech 2?

[Davis]

nigeljones,
If you can use a Tech 2 that would be best. The Snap On scanner will not give you the correct values like a Tech 2. I own a snap on scanner and it provides the TDC offset values in snap on data NOT GM`s data. I spoke with a snap on rep. about the problem and he said it was not an issue and to use the Snap On values that are listed in the trouble shooter cartridge. Needless to say I am not happy with that and as soon as I can afford a Tech 2 then the MT2500 will be sold. Good Luck Davis.

[Turbine Doc]

Davis what value are you seeing on your snap on, I think it's okay to use once you understand it, both Billman & myself have correlated for a snap on reading of -5.4 is equivalent to -1.94 on T2.

My truck ran for 1st 2 years with -4.2 which I have since learned correlates to about .-76 on a T2. I've not looked at other numbers to make a chart to see if a linear correlation between the 2 can be drawn. Once you understand it for an OBDII truck a used T2 isn't a bad way to go. That said, I'm eyeballing the AUTO enginuity laptop tool GMC Hauler is having success with.

One other plus with a MT2500 is that it's caplbel of being used on other domectic as well as GMC & Chevy.

Nigel & I just got off the phone, he is having some unique readings & results I don't quite understand but we are working thru them.

[Davis]

I did not see that you needed the procedure so here is one out of a GM sevice manual 1996 up.
1. Connect Tech 2 diagnostic computer to the DLC connector.Turn it on and enter the info. for your vehicle.
2.Select Data list from main menu and view ect data parameter.
3.Start engine and run until ECT is greater than 170 deg F.
4.Use Tech 2 to clear PCM DTC`s.
5.With ignition switch in Run and the engine Off,hold the accelerator pedal at WOT for at least 45 seconds in order to prepare the PCM for learning process.
6. Move the ignition switch to lock for 30 seconds in order to allow the PCM to power down.
7. Verify the PCM has cleared the TDC offset by selecting DATA list and viewing the TDC offset data parameter:
- If the value is zero, continue the procedure.
- If the value is not zero, repeat the previous steps.
8. Start the engine and run until the ECT temp. is greater than 170 deg F.
9. Allow the engine to run below 1500 rpm so the PCM automatically learns the TDC offset.
10. Verify that the PCM has learned the TDC offset by selecting DATA list and viewing the TDC offset data parameter.
-If the value is between -0.25 and -0.75 the procedure is complete. (These are GM SPEC`s.)

Now substitute the -1.94 value in place of the GM spec`s. and try this procedure.
Hope this helps. Davis

[Davis]

Hi Tim,
When I talked to the Snap On Rep he could not give correlated numbers as you did with your previous post which is good to know. Now I also have a problem using the Snap On scanner with my 94 p/u it does not even provide a Time set menu option for a 1994 or 1995 GM diesel. Will yours work on the 1994 and 1995 diesels ???? Thanks Davis

[Turbine Doc]

I've not tried it on OBDI, but I also have an oddity in mine maybe similar to yours, my time set function is not active unless I lie to the scanner and say it's a F engine truck and not an S. It was explained to me that 1/2T S trucks are rarities so full function of the tool was not active for those. I don't know why but if I do it as described it works, go figure.

[JohnC]

Nobody I know of has figured a way to get the ODB 1 trucks to learn the TDC offset without using a Tech 1 or Tech 2.

[nigeljones]

Davis,

1, When using the Tech 2 and doing a TDC offset learn do you have to manually move the pump to the desired position or can you do it thru the tech 2. I thought JK said it was the way to go set and forget!

2, How do you set the base timing with the tech 2. I would like to re-check that using the tech 2 if I can.

Thanks

All.

Update - When I used the Snap on MT2500 and talking things thru with Tim(tbogemirep)Later that evening.I could not get the TDC offset pass -.86 and at that value I would set the timing code as previously stated. The vehicle data that I enetered for my truck was for that of a 97MY. I then changed it to a 96MY and my TDC offset changed to -0.1. I did not complete a TDC offset learn the numbers changed when different MY where entered. The data prompts within the scanner state that the spec should be between -0.25 and -0.75 for both MY which are the correct GM values.This is different from Tim's MT2500 scanner.

At the values stated the truck starts right up and seems real strong so.

I hope to get access to the tech 2 tomorrow so I will update you further


Thanks

[Davis]

nigeljones,
Hi, Yes you will need to rotate the pump to change the values for TDC offset.But do it in very small incriments as they are sensitive.Maybe move the pump the thickness of a postcard at the time.
You will need to achieve the TDC offset value that you desire first before checking the base timing.


Timing prcedure :
1. Start engine and bring to operating temp.
2. Connect Tech 2 and select Special functions from the main menu.
3. Select output tests
4. Select Injection pump
5. Select TDC Time Set
(I do not own a Tech 2 but I asked someone that does to help me with my truck and it seemed like there was four buttons under the display and he pressed one of them and it manually made the computer go to base timing and that is when you need to look at the actual timing data which should be 3.5 deg )
I actually left my truck running while he had the computer commanded to base timing and adjusted the pump while looking at the Tech 2 display and stopped moving the pump when it was averaging the 3.5 deg. Some of the members may not agree to leaving the truck running but the guy that was helping me is a Chevrolet diesel tech and said it was ok.Although I did not have the nuts on the pump real loose so it would not move while the engine was running.
Again these steps are in a GM service manual so I hope they help.
Hopefully another member may know which button to press to command the base timing because this book does not say. Good Luck Davis

[nigeljones]

Update.

I was able to get hold of a Tech2 yesterday and I was suprised at the ease of use. There is not much difference between the Tech2 and the Snap on MT2500 with the trouble shooter module. So time set and TDC offset was very much the same. The terminology was almost identical and my preference at this point, if considering a purchase, would be the Snap On, as the Snap On gives tips and how too trouble shoot and also identifies the factory spec's. And I am assuming the Snap On to be cheaper than the Tech2

The problem with the Snap On was the different values it reported out for TDC offset whether it was a 96MY or 97MY. If they where to be correct it it would be very usefull.

When comparing the Engine Data 1 everything else checked out to be the same.

With that my actual TDC offset with the Tech2 is -1.76 which would equal -0.1 for the 96MY and -0.79 for the 97MY. I was very pleased as I had set this by eye. Knowing that with the 97MY values a -0.86 would through a code and that above -1.94 using a Tech2 would do the same, I just set it back from the -0.86 just a smidge, as you all had indicated and it doesn't take much.

I could not find within the tech2 anyway to adjust the TDC offset without manually adjusting the pump. So i don't agree that it any easier with the Tech2.

I like the idea of adjusting base timing on the fly with the engine running. However, I had to disconnect the fuel return hose to be able to get the wrenches to swing to tighten and untighten the adjustment nuts. It did occur to me at the time to lengthen the hose.

Thanks to all that have help me with my issues as of late. :D

[nigeljones]

Davis

You might want to review your statement

[QUOTE] You will need to achieve the TDC offset value that you desire first before checking the base timing.

As I found that you have to complete the base timing first.

Then complete the TDC offset learn proceedure

At least thats what the Snap On Scanner told me

Thanks

[JohnC]

Originally posted by nigeljones:
I could not find within the tech2 anyway to adjust the TDC offset without manually adjusting the pump. I think there is a missunderstanding being perpetuated out there. It doesn't make sense to talk about setting the TCD offset with the Tech 2 any more than you can adust the distance between 2 cities with your odometer. The TDC offset is the measure of a physical parameter of the engine, to wit the difference in degrees between the crankshaft TDC as measured by the crank sensor and the pump TDC as measured by the optical sensor. The only way to change this is to move the pump (within reason). The reason you can get different readings under different circumstances is that you are measuring a very small parameter in a very sloppy system.

JD has raised questions about the difference between reading the correct value and reading a value that is "incorrect". I wonder too...

Too many questions, too little time....

[fastcat800]

I'm with you John. It didn't make sense to me either. I love your analogy about the odometer.

[Davis]

Hey nigeljones,
The reason I said to do the TDC offset procedure first is because when you achieve the value you desire whether it is a -1.94 etc. then the ECM has that value in its memory. Next you will set base timing and you will probably have to readjust the pump again and when you get the base timing on the 3.5 deg mark then you will not want to move the pump anymore other wise you will be moving an excessive amount of times. Good to here you like the snap on scanner but I like knowing the actual values that the Tech 2 produces and like I posted ealier my MT2500 will not even show the TDC offset learn or Time set function on the menu for 1994 and 1995 trucks but will show it for the 1996 up.Go Figure. Well its good to hear you have the timing set. Hope it helps your performance. Davis