Just got my scanmaster hooked up and took it out for a test. I went through all of the modes, checked for codes and pretty much everything was reading pretty normal.

After that, I went through specific modes with some WOT runs. From the Scanmaster I learned that I'm getting 5.0 degrees of Retard.

I'm wondering what could be contributing to this. Is it a simple tuning issue? I have heard from some of the more advanced tuners here that the PCMforless Hot Cam tune isn't as great as it's cracked up to be, and could use some work. What are some things I should do to eliminate this retard? Switch to LT4 KM? Dyno Tune (later on)? Thanx for any ideas u can contribute.

 

Probably just a little too much timing on the file.
Not sure if the LT4km would help or not.
Don't you have one in the car now?

 

I HAD one actually, it went bad when i put it in Bryan's PCM. For some reason it would SEVERLY retard timing, it was really messing up the car. So i switched back to his and it ran great. I dunno if it coincidentally went bad when i swapped it from mine to his or what, but it was weird and I'm apprehensive about trying an LT4 KM again.

 

Did you "see" the retard readings for an extended period of time, or was the 5-deg "recorded" after a WOT pass? If it was recorded, what was the corresponding MPH? Does that correspond to your shift point?

 

Yea, I actually saw the reading on the retard degrees as soon as I hit WOT, and it continued throughout WOT. I had a passenger verify this and had him keep an eye on it as i tested it. I didn't actually record it, I'm not really sure how to do so.

I also noticed that the amount of retard I get is proportional to the amount of throttle I give. If I'm at light throttle, 1 degree or less of retard. At quarter throttle, about 2 degrees. WOT is the worse, where it hits 5 degrees and holds their.

Any other readings I should check on the scanmaster at WOT to see if it can help diagnose my problem? thanx fred and dan

 

After the last pcmforless hotcam file I saw I can recommend this...
Try and watch your O2's in a good 3rd gear pull and see if they start to drop as rpm increases.
Also, watch blm and see if it goes above 128.

 

Would this mean that I have a bad tune? Or some other problem? Some ppl think I have an exhaust leak, but I don't see or hear one. Others say i have a bad fuel system. I dunno what it could be personally. Which mode is BLMs on the scanmaster? Which O2 sim should I watch? right or left matter?

 

I didn't say that. I'm not going to step on anyones toes. All I'll say is that a mail order tune is sort of like a one-size-fits-all.

I think on the scanmaster in my GN blm is labeled bl. O2 has different values for you to see? Do they give you the choice of right and left side or something? If so, you should be able to watch either.

 

Yea, there are O2 Sims on the right and Left bank. I believe I hooked my air-fuel ration gauge of the the left bank. The mode that reads 02 readings and knock I believe is reading from the right bank, but I'm not sure. Injuneer, u should be able to clarify this, and I appreciate u making that Scanmaster article on your webpage, VERY helpful

 

Whats your knock count before, and after the wot run?.

lt4 module might filter out some false knock, but that would show in your counts.

 

Does a scanmaster show knock count, or just retard?

 

The ScanMaster only shows degrees of spark retard. Doesn't show knock count.

As noted in my online writeup, the original instructions that came with the SM were contradictory, indicating in one place the the default "KR - O2" simultaneous display was indicating the "left" O2 sensor. And in another place it said something about showing the "average of L+R".... so i can't answer with certainty. I think when I tried to check the default display by switching to the individual O2 readings as the sensors warmed up, the default display was the same as one of the sensors, but I can't remember which one. Since I went to leaded fuel, the sensors aren't really worth looking at any more......

 

I am having this same problem, left bank leaner than the right and retard sensor is reading 5 degrees.....what did you do get this resolved?

 

<-- Experiencing an exact problem here after heads/cam

 

Unfortunately, the problem is still unresolved

Any other opinions would be appreciated.