12200411 PCM swap for 1996 to 2000 GMT400 trucks

[1998_K1500_Sub]

I moved the dizzy 1 tooth clockwise and it was just as bad
Now im back at the original -6 and the dizzy is hitting the intake

Often the gear has to be rotates 180* on the shaft in this type of situation. I had the same problem, and when pushed to -4 it was good enough to leave alone. Then updated to coil packs to remove that feature

This swap sounds fairly common. Shouldn't everyone be having or "have had" the same problem(s)?

Maybe I just need to read-up on this swap more... I swear I've read that "it's just a matter of swapping a few pins in the connectors", but I don't remember reading about this distributor / CMP Retard monkey business.

I guess I should start from the beginning of this thread and read all posts.

 

[Spareparts]

The 0411 swap was very easy. Just swap 1 wire at a time and swap them all to the color you start with then do the other color. It really was very easy.
I suspect my distributor has been off since the day i got it but seemed to run fine. It never had a code either.
I had to do the crank relearn and i thought i better check the cmp first. That's when the problem started.
It still seems to be running ok but i need to get the cmp fixed so i can then get the crank relearn set. Might try to fix it tomorrow.

 

[Spareparts]

Going to UT University i found this video. everyone has probably seen it but just in case you haven't it's very good. Long winded but worth the watch.
I have another dizzy here that appears to be in great shape i'll install today and see if it changes rather than messing with the gear on the installed one.
It did just occur to me though that maybe my timing chain is stretched enough that that could be the problem i wonder?

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[Spareparts]

Well it appears my dizzy was originally set properly i believe.
Swapping distributors cured the problem. I now have it set to +0.8 and it will very up to +1.0. Not bad and it's well within the 0 +/-2 and varying 0.2
So the old dizzy i believe you will see the problem if you study the pic

 

[Spareparts]

Just got done trying to do the crank relearn and it won't do it. Message says, out of range. So now i don't know what to look for

 

[Piratehunter]

That old gear was possibly worn due to setting too tight on the oil pump shaft, putting too much pressure on it. See this link for shimming the dizzy to the manifold https://www.chevyhardcore.com/tech-...t-distributor-gear-its-all-about-the-details/

worth checking the gap under the dizzy to the manifold.

Use a mellonized gear, Amazon has a GM one and Summit has one too.
if you end up pulling your dizzy again, use a bore scope and check the wear on the cam gear related to the old dizzy gear wear. Could be a hidden problem.
If your dizzy plug wires are too tight against the upper manifold, I suspect your dizzy gear is off 1/2 tooth, drive the pin out and turn the gear 180. Had similar problem, though your cmp is in spec.

I recall seeing either in the service manual engine electrical section linked a few posts back or a google search I did sometime back had some causes for the out of range message. Was there a P code number with it?

 

[Spareparts]

The original dizzy had a bad gear causing it to be out of spec and untunable. The new (used) dizzy had a good gear that did not look to have any ware and is now adjusted properly.
The code is P1336

 

[BeXtreme]

The original dizzy had a bad gear causing it to be out of spec and untunable. The new (used) dizzy had a good gear that did not look to have any ware and is now adjusted properly.
The code is P1336

Did you have the pins grounded per what I said in post #758? The 0411 needs to know you have it in park or neutral in order to run the CASE relearn

 

[Spareparts]

Well S**T i did not, totally missed that little fact somehow.
I did however remember reading a few posts saying to get PRN0DL to work you needed to tap into the wire harness at the cluster or trans.
Mine is working without doing either. So i assume the ecu would know if it's in park or neutral and parking brake set.

 

[BeXtreme]

Well S**T i did not, totally missed that little fact somehow.
I did however remember reading a few posts saying to get PRN0DL to work you needed to tap into the wire harness at the cluster or trans.
Mine is working without doing either. So i assume the ecu would know if it's in park or neutral and parking brake set.

No, the ECU does not get those signals. You have to tap into those signals at the cluster or trans in order for the ECU to get that signal. OR you need to ground those two wires so that it thinks it is in Neutral or Reverse and allows the CASE relearn to happen.

If you don't do either of those things.... everything will work just fine except for the case relearn and anything else that that requires you to be in Park or Neutral for. Personally I just ran the wires from the PRNDL switch to the ECU on my swap.