1994 Can’t time Set or set TDCO with Tech 2

[ak diesel driver]

Try moving the other direction then

 

[Twisted Steel Performance]

Man I love my manual IP..... sorry I couldn't help it ...

 

[dbrannon79]

Just curious, could it be something with the tech 2 not being able to clear the codes or set the TDCO? I have not used a tech 2 before but I do have the GMTDscan on the laptop.

 

[Will L.]

Man I love my manual IP..... sorry I couldn't help it ...

Glad I wasn’t the one this was time. If I had, my timing would have been off. But db2, so that doesn’t really happen....

BigT- ya might need a turkey sandwich break. I know I do.

 

[Big T]

OK we downloaded GMTD Scan to a windows 10 laptop and got it to work. Can clear the DTC 88 code, but it comes right back the moment we try to do a Time Set. So we are unable to do the TDCO learn. This does not change no matter how we move the IP. I am now wondering if this is the wrong IP?

 

[dbrannon79]

something you can check. once you can get close to 3 deg on the actual IP timing. look at the fuel rate numbers. this IP could have the OP sensor out of whack and not adjusted correctly. if that is the case, your fuel rate at idle will look funky rather that be a 6-8 mm^3. I know Will will know more about this than I would.

 

[dbrannon79]

if you got a 5068 IP rather than a 5521 IP, would that do this where you wouldn't be able to get the timing right?

 

[ak diesel driver]

AFAIK the 5068 will time just fine, just won't run right

 

[ak diesel driver]

You are doing time set first, right?

 

[Will L.]

Nope sorry. I am not the ds4 guy. Been decades since I computer-wrenched one.

 

[Big T]

You are doing time set first, right?

Trying to do Time Set first, but obviously don't know how to do it. I now understand that I put the GMTD scan on with engine running and at the right temp, then move the IP until the Actual is at 3.5, then I do the time set command. Is that correct? Then it should set at 3.5 and we can do the TDCO command.

 

[dbrannon79]

As I understood it thats kinda like how it's done with a timing light and moving the distributor disconnecting the vacuum line on the distributor on a gasser. only using the pc triggering the time set, leaving the IP snug where you can tweak it back n fourth while idling. once it's at 3-3.5 deg and seems steady then tighten the nut up and trigger learn. I may be wrong where others can chime in to correct me. the tech 2 should have a time set function and a learn function same as GMTD on the pc.

 

[ak diesel driver]

I believe so. Don't mess with OBD1 very much

 

[Big T]

This morning’s effort.

During time set:



After time set:



It’s no longer setting codes. We’re going to leave it there, unless instructed otherwise.

 

[dbrannon79]

Awesome! that looks like a good number. is it running any better?

 

[Big T]

One final attempt and turned it off at this:

 

[Big T]

Awesome! that looks like a good number. is it running any better?

Not really noticeable. The whole time it has been running good. Most important, not throwing TDCO code (fingers crossed). I left the bent IP wrench and fabbed adjusting tool with my son.

 

[Big T]

It’s running nicely….

November 28, 2021

youtube.com

 

[MrMarty51]

Thats great news.

 

[Big T]

Colby drove it to work yesterday, which is 9+ miles away and no codes and no issues. Considering this portion of the project done.