Spark not advancing more that 17 degrees???

[jeffpark_]

I've been trying to get a 2002 4.3L Vortec tuned, and noticed that my spark is not advancing and does not seem to be following the base tables; it is always at 17 degrees or less.

I've been working on this for a couple of days now and I've pretty much given up solving it on my own--please help!

I've attached the log and tune file.

[ScarabEpic22]

I just downloaded and looked at your file, why are you running a COS? And you mention its a 2006 4.3 but the tune says 2002. 06s use 1mb PCMs and 02s use 512kb PCMs, just trying to figure out what you're trying to do here. Maybe a list of mods would be helpful too.

[GAMEOVER]

Welcome to the forum!!!

[GAMEOVER]

Like Erik asked,
What mods have you done??? If any....

[jeffpark_]

2006 is a typo-it is 2002 (in a 97 blazer chassis). I was very sleepy when I posted this...maybe subconsciously trying to make my truck newer! Thanks for the welcome.

The engine is out of a 2002 ZR2 S10 and the PCM is a 411 from another Blazer.

The engine has a 260HR cam from comp cams, JBA headers and was converted to a manual NVG3500 transmission. I've been running with the MAF off as it causes surging issues with it on.


-Another note-
It has been throwing a P1345 code so I checked CMPRET. The error it was showing was -109.8*.

I tried adjusting the distributor as mentioned in
http://forum.efilive.com/showthread.php?t=9411&highlight=p1345
but there is only 1 tooth that the engine will actually run on. Could this error be related to a bad sensor?

[GMPX]

It might be defaulting to a timing limit because of that P1345 "Crankshaft Position (CKP)-Camshaft Position (CMP) Correlation" code.

[nqcv8]

try turning off Torque limiting.. forgot to do this myself one day.. had the same problem. No matter how much timing was in the tables wouldnt increase.


Cheers

Sean

[jeffpark_]

try turning off Torque limiting.. forgot to do this myself one day.. had the same problem. No matter how much timing was in the tables wouldnt increase.


I just tried disabling Torque Limiting, but no success resolving the spark issue.


It might be defaulting to a timing limit because of that P1345 "Crankshaft Position (CKP)-Camshaft Position (CMP) Correlation" code.

This is kind of what I was thinking, but I'm not sure how to get rid of this error. I tried just disabling the P1345 code, that didn't change the spark. It is still 17* advance all the time unless it has KR.

Could this be related to a bad distributor (was recently replaced), a bad/wrong crank position sensor or another sensor? Most of the sensors are from the 97 engine and I guess there could be differences.

I was able to do a crank relearn, but it didn't resolve anything other than changing the error angle to -106.8* instead of 109*.

[ScarabEpic22]

Do a CMP relearn, open up the DVT tab and find crank position relearn and do it. Might help out

[2002_z28_six_speed]

Props to the OP.

I think he has already tried the CMP relearn and it didn't help. Mad Z toolness.

[poolshark021]

Make sure the distributor is actually for a 4.3. The 5.7 distributors are identical except for the clocking of the cmp interrupter. If you pull the rotor off there will be a '6' or '8' stamped on the metal underneath it.

[rpmauto]

i dont know if this will help, but what is the cam sensor(distributor)reading as far as correlation?? i know it should be +or - 2% and the 4.3s are a bear to get right, you can make the distributor adjustable by elongating the hold down.

[2002_z28_six_speed]

Make sure the distributor is actually for a 4.3. The 5.7 distributors are identical except for the clocking of the cmp interrupter. If you pull the rotor off there will be a '6' or '8' stamped on the metal underneath it.

I think most of the aftermarket distribs have 6s and 8s marked on them. They could be so general purpose that they don't work well in either. It's possible....

[2002_z28_six_speed]

No news? Where's the news? We have to have the news!!