Crankshaft Position System Variation Learning Procedure

[cyborg50]

hello
I got a 2002 chevy blazer 4.3 with bad engine and tranny. (blown engine)
The engine and tranny was replaced. the donor was 2004 s10 - no computer i can't test this engine in the car.
After surgery the engine starts good, drives good but: the engine have rough idle - only a little. It's not like one cylinder is not working rather i say irratic. On the idle no codes.
If the engine goes above 1900-2000 rpm - i got 300 or 304 codes but as i said - no sign of dead cylinder. The spark plugs, cables, whole distributor with cap, coil replaced - no change, pickup, evap, map, PVC - no change. fuel pressure around 60. no smoke, oil pressure good, already 10.000 miles on the new engine.

I found that "Crankshaft Position System Variation Learning Procedure." might be needed after the engine/pickup replacment, but only a scan tool can command the PCM to perform the Crankshaft Position System Variation Learning Procedure.
I live in Poland and i have no acces to gm scan tool, my lame scaner can only shows codes and turn off the service engine light.
I found that EFILive can do CPSV Learning Procedure. Is it true?
Do you guys think that CPSV Learning Procedure can help?
Anybody try to run 2004 engine with 2002 wiring and computer?
I know that the spider system is different in 2002 vin w and the 2004 vin x.

Help me Obi-Wan Kenobi, you’re my only hope

[rpmauto]

possible clogged poppet valve(injector) YOu could try running some good cleaner through the fuel rail, ie gm top end cleaner and disable the fuel system. Just a thought, those injection systems are notorious for issues.

[cyborg50]

My blazer is bi-fuel. When i go on propane the problem is the same. Anyway I bought new spider web. Just wait until i get it.

So, anybody know do i need "Crankshaft Position System Variation Learning Procedure" without the P1336 code? Can efilive force the learning procedure?

thx

[schwoch1]

There really is no 'learning' procedure when it comes to timing the Vortec V6 and V8's. You have to look at the camshaft error PID and get it as close to zero as you can by turning the distribuor and reving the engine past 1100 RPM to get the PID to update. I am fairly sure that EFI live has that PID avaliable, but I am not 100% sure, I do know my Snap On Solus Pro will do it.
Hope this helps!!

Mike

[cyborg50]

Yesterday i do "ckp relearn pocedure" and .... works :)
Instant fix.

thx

[hquick]

There really is no 'learning' procedure when it comes to timing the Vortec V6 and V8's. You have to look at the camshaft error PID and get it as close to zero as you can by turning the distribuor and reving the engine past 1100 RPM to get the PID to update. I am fairly sure that EFI live has that PID avaliable, but I am not 100% sure, I do know my Snap On Solus Pro will do it.
Hope this helps!!

Mike

Yes there is a learning/re-learning procedure.
As you stated...timing needs to be +/- 2 but a crank relearn is necessary for crank and cam correlation. This can only be done with an appropriately equipped scanner.

[schwoch1]

Yes there is a learning/re-learning procedure.
As you stated...timing needs to be +/- 2 but a crank relearn is necessary for crank and cam correlation. This can only be done with an appropriately equipped scanner.

Basically watching the scan tool after you rev engine past 1100 RPM, and see what the cam/crank error is, adjust the distributor and repeat until perfection.... I suppose you could call that a procedure, more of a pain in the a$$ than anything else I guess. I like the LS1 motor for cam/crank error, rev it up and let the computer do the rest.... how much easier could life be :)

Mike

[hquick]

Here's a bit more info on the 'procedure'.

http://www.trifectaperformance.com/tech/crankrelearn.htm


What is “crank relearn”?



“Crank relearn” refers to a GM service procedure that has to do with the calibration of the PCM to a specific engine’s crankshaft position sensor (CKP sensor). When your Gen III (LS1, etc) or Gen IV (LS2, etc) based car or truck was put together and factory-tested, one of the procedures it went through was the “crank learn” procedure. The PCM has the ability to contain detailed information about how the specific engine in your car operates, and it must have this information in order to run the engine optimally under all conditions. One key piece of information pertains to how the CKP sensor reports its signal to the PCM.



If a vehicle’s PCM is changed out, there is a chance the new PCM will contain incorrect information about how the CKP sensor reports its signal to the PCM. If the new PCM’s information is incorrect, and the PCM cannot self-correct it, it will set the P1336 Diagnostic Trouble Code and turn the SES light on. Aside from the annoying SES light, vehicle performance may be affected, and emissions systems may be compromised.



Introducing the Dreaded P1336 Diagnostic Trouble Code (DTC)



According to the GM factory service manual, the OBD-II trouble code, P1336, is defined as follows: DTC P1336 CKP System Variation Not Learned. The factory service manual does not enumerate all of the symptoms of this trouble code, but after consulting a professional custom PCM tuner, it was learned that aside from the annoying light on the instrument cluster, the other symptoms exhibited may include: poor vehicle performance, and loss of misfire detection diagnostics.



This DTC is particularly nasty, because simply clearing it by disconnecting the battery, or clearing it using an OBD-II scan tool will not address the problem. The code will be set again later unless the vehicle is run through the actual “crank relearn” procedure.



Fixing the Dreaded P1336 DTC



There is only one way to properly fix the P1336 DTC, and that’s to perform a “crank relearn” procedure, or as the GM factory service manual procedure calls it, the CKP System Variation Learn Procedure. This procedure can be initiated and performed by GM’s be-all end-all scan tool, the Tech-2. It can also be performed by some aftermarket scan tools. Furthermore, some of the PCM tuning software applications are capable of initiating a “crank relearn” procedure.



For most enthusiasts that encounter this issue, the best course of action is to bring the vehicle to a local GM dealership and have them perform the procedure. Unfortunately most dealerships will charge a modest fee for doing this (upwards of USD $100 in some cases).

[schwoch1]

Here's a bit more info on the 'procedure'.

http://www.trifectaperformance.com/tech/crankrelearn.htm

The engine in question here is NOT a LS style engine, therefore this procedure is not correct. The crank relearn procedure is not the same for the Vortec 4.3/5.7 engines as it is for the LS style engines. The Vortec motors (4.3/5.7) still use a distributor as a cam referance signal and the distributor has to be moved to get the camshaft position error correct!

Mike

[hquick]

Yep! I should have read the initial post better.
Donor engine being a 2004.
So now I'm curious. How did 'cyborg' do a CKP relearn?

[cyborg50]

2004 s10 engine looks exactly like my old 2002 blazer engine. All plugs fit, so I got the engine from s10 into blazer without thinking too much.
It starts OK except as noted above. It took me a while to figure out the problem. The misfire section of the GM Shop Manual does not mention ckp relearn procedure, but if you look up the 1336 code it says that you need ckp relearn if you change the engine, computer or ckp whether 1336 code is set or not.
Finaly i found a guy with a snapon mt2500 scanner and we do the ckp relearn procedure.

[hquick]

Schwoch....can you explain why a relearn procedure was necessary....or is it a different CKP relearn to the full sized truck motors?
OK....I'm confused.
So...is this 2004 s10 engine a Gen1 style Vortec engine?
I posted the details in a previous post which mentioned LS1 & LS2 only because it was the first thing I found using a quick search that went into a reasonable amount of detail.
My 1998 5.7L L31 requires a CKP relearn if the PCM is swapped out or it will throw the same P1336 code.
Foot on brake
TPS at '0'
At full operating temp
Rev until fuel cuts out then take foot off pedal. Done!
Is it different for the 2004 S10 4.3L motor?

[cyborg50]

Foot on brake
TPS at '0'
At full operating temp
Rev until fuel cuts out then take foot off pedal. Done!
Is it different for the 2004 S10 4.3L motor?

No. It was exactly the same.

[hquick]

That's what I thought initially.
I have performed a CKP relearn on my Burb a few times.
To answer one of your original questions....YES...EFILIVE does have the necessary functions to perform a relearn.