HELP!! Tech 2 Scanner issues..... Cant time this thing

[DIYORPAY]

I cant seem to get my PCM to learn , or change my actual/desired timing at all. I have moved the pump to passenger side way over 1/4 inch and still no change. KO/KO procedure seems to do nothing after i move the pump. The scanner says i have +10.5 actual and +10.5 Desired timing. ECT is at 189 degrees.

Does anyone know what could be wrong? I do have a reflashed Heath GL4 pcm. Does that matter when doing timeset? The engine runs fine but is pretty loud(advanced).

 

[JiFaire]

189* on the tech II?

The only thing I can think of is... you have 2 coolant temp sensors; one in the thermostat housing and one in the driver's side cylinder head. There is a difference between the one that tells temp (to the gauge cluster) and the one that feeds temp information to the PCM for engine functions.

The one that feeds the PCM is in the thermostat housing..

Then again, this might not be at all related, but if your engine is warm enough and you press learn, you should get action.

 

[DIYORPAY]

I dont know where the learn function is on the scanner. So i did the KO/KO procedure.

 

[DIYORPAY]

What ECT should it be reading it the sensors are fine? It says....

engine start temp is at 186 and temperature went up to 188 and i saw 189 once at idle.

 

[JiFaire]

I dont know where the learn function is on the scanner. So i did the KO/KO procedure.

Send a quick PM to Stacks04 - he can give you some advice on using a Tech II. As long as you have one handy, you might as well use it.

 

[buddy]

I think the problem may be that you are not looking at the right items. Your desired timing is controlled by the PCM program, you cannot change that. And the measured should read the same. The only time you will ever see anything different is during timeset, which you are not doing with the scanner so you will never see it. That is when you would see 0 desired and what would be the base of 3.5ish.

Are you looking at the TDCO value, what is that value, it should be changing.

 

[bk95td]

Desired and actual should be 3.5 WHILE in timeset

 

[DIYORPAY]

Thanks guys! I figured it out. Ive got one more night(after work) that i can use the scanner, so hopefully i can get it right on. I got it timed pretty close now.

 

[JiFaire]

Thanks for the help, guys... what I know about Tech IIs would fill a small thimble...

 

[DIYORPAY]

Well i thought i had it......... i got 3.5ish, when in timeset, but the tdco doesnt seem to change. It made one drastic change(from +1.41 to -2.46) Now i cant get it to go up to -1.5. Which is where i want it. Ive moved the pump alot without (about 15 times in small increments)and it wont go back up. Its stuck there!

 

[buddy]

it may read -2.46 until you get it below that, so no matter how far you move it out of tolerance it will keep reading that. You need to bring it in far enough to change it.
You are clearing the DTC and running the timeset and TDCO relearn each time you move the IP? My OBD1 reads -2.02 anytime its out of tolerance, doesnt matter how far it is, could be a mm, could be an inch.

 

[DIYORPAY]

So even if the actual doesnt stay at 3.5 and i get the TDCO to -1.5 or so(while in timeset) then its fine? i can get the 3.5 while in timeset but the TDCO is off. Am i doing something wrong? Am i missing a step?

My procedure went like this...............
Turn pump and tighten the nuts.
Turn on ignition and check/erase any DTC's
Start engine,
Make sure ECT is above 180
Recheck for no DTC's
Cammand timeset
Check that actual is 3.5ish
Check TDCO(usually -2.46)

Turn off engine and bang head on something hard!

Am i missing a step?

 

[NVW]

I"m not familiar with Tech 2 but with Carcode or GMTDScan you command a TDCOffset learn while in Timeset. The learn can also be commanded out of Timeset if it (Timeset) has already been done.

 

[DIYORPAY]

Thats kind of what i was wondering. I may be missing a step here. When i used a tech 1 a few years ago to time my 95, i had a book. I thought it was simple. I wish i had a book for the tech2.

 

[buddy]

If you actually are getting 3.5 degrees actual in timeset you should not be at -2.46 TDCO. You may just need to command the TDCO relearn again, because in your steps you just mention checking TDCO, but never commanded it? I have to command timeset, then when I end Timeset I have to command TDCO relearn. I use GMTDScanTech, but I would assume you have to command TDCO relearn.

To get a -1.5 TDCO you might need to get an approximate average actual base timeing in timeset of 3.7 degrees.

What this means is that at 3.5 degrees cam timing you are at 7 degrees crank base timing, and when you go to about 3.8 degrees cam base at -1.94 TDCO you are at 7.6 degrees crank base timing. So using TDCO as a basis for "advancing" the injection is little bit of a fallacy. But it does affect injection, and most likely increasing the IP transfer pressure so you get a bit more fuel output. Because we have the electronic timing control it doesnt matter what IP pressure is, because the electronics will correct the timing to what is programmed. Thats why regardless of where you are on a TDCO you will always see the same timing when idling. So with your GL4 you probably have enough power so a TDCO of -0.75 to -1.5 would be fine.

 

[DIYORPAY]

Thanks Buddy. Now does anyone know on a Tech II how to command a TDCO learn? I have not done that because i didnt see it on the screen. This may be the only thing i need to do yet. As long as i have anything between -.75 and -1.5 i would be happy. I would like it to be a little quieter when its cold out.

 

[buddy]

Never used a Tech-II but you can just run KOKO procedure and it will run the timeset and TDCO relearn on its own. Then you can check the TDCO on the Tech II

 

[DIYORPAY]

I will try that. Thanks again!