Craig,

The threads on those clamps must be a little week or either we are torquing them too much becasue I stripped the same clamp as you mention. Tim sent me a knew one along with a recent chip he had modified.

I also think the "tie wraps" may have had something to do with the back part of my MAF cracking as I think I had too much force pulling back or stright down on the elbow forceing the MAF to hit the hard fuel fitting. I didn't mention above that by pulling the elbow too hard I had also created a small leak down at the lower boot. (somehow we have to keep the MAF orientation stright but with some pressure)

Here is a pic of my latest straping which seems to work better. It gives a more correct "angle of pull" keeping the MAF seated in the rubber boot with the orginal "weak" worm clamp. This tie is actually wrapped around a leg of the manifold which pulls down in the same angle

Hope this helps a little.

 

Andrew,

My car is "newly" boosted with the stage III and currently working out the bugs. Please give me a link or a little more info on the O2 sensor you are speaking of. Sounds like need to change over.

 

David-

At a minimum, you should have a Wide Band O2 sensor. I recommend the Innovate LC-1. For the gauge, they have a really nice inexpensive one called a DB gauge. They have a "bundle package" for about $300 that will give you the best deal IMHO.

http://www.innovatemotorsports.com/products/db.php

No affiliation.

Edit: Some information removed becasue it was wrong.

 

Thanks Andrew, I just ordered it!

 

Hi Craig,
Sorry I couldn't answer before. The chip Tim has supplied should work OK, as long as you have no airleaks, fuel pressure is set as he requires and your MAF is OK.

The weak running does suggest an air leak.

Tim's kit may not use the expected injector size setting in the paramters screen because he uses a MAF restrictor to extend the operatring range. This is something I have not experimented with yet.

To answer Bill Ball's comments, yes it is sometimes necessary to offset the injector size setting by a small amount to get all the SharkTuned cells within the +/- 128 range. This is covered in the ST manual.

But this is not related to whether the car is S/C or not. The car will require the same amount of fuel at a particular cell point (i.e. load) whether boosted or not. The S/c car will of course go to much higher load cells in general.

 

Thanks John,
I'll look for the air leak as suspect #1.
Just as a point of understanding the SharkTuning process better tell me if I understand this part correctly if you would.
In addition to the chips Tim sent that he tuned for the StageIII kit I have the files for those two chips currently loaded into the PEM's installed my LH and EZK .
If I remember correctly I can open a copy of the files Tim created in the SharkTuner and then auto tune within those maps and then save them? My logic is I could write over the cells I need to correct a problem but not re-write over the parts where my car runs at the ratio I want it to.

I realize in my current situation that I need to be sure all my mechanical components are correct so I don't tune-to-hide-a-symptom so to speak but just in general is my understanding of how I could use those files correct?

The reason I ask is he has tuned those files on a dyno so he was able to get the WOT and higher rpm cells with ease where as if I try to visit those cells on the local roads for any length of time I'll end up in jail or else not give the proper time and attention to the process in order to avoid the police...

Thanks!

 

Hello Craig
Yes you are correct. Bear in mind that when using a PEM with ST, any changes (e.g. Autotune) are written directly to the EEPROM in the PEM, and will remain until you edit then in the future.

When you "save" or "save as" you are just saving the file on your laptop. The editted data is already "saved" in the PEM.

I recommend always using "Save as" after any edit. Then you can properly archive your chnages on your laptop.

 

Andrew:

I just installed an LC-1 and was starting to install the XD-16, so I appreciate your comments. I will be back later about that after I get it together.

Also, in looking over the logs again, I see some odd stuff. Note how early in the long cruise section that AFR is reasonable to even rich for cruise (red circle), then later on it goes lean and stays there (yellow circle). Lots of bouncing around too. It appears in the red area you are decelerating somewhat (but still in cruise area of throttle with only a few exceptions) and then get into a little more pedal to maintain the cruise and it goes lean despite the higher MAF signal.

 

I felt and observed the same thing on partial throttle acceleration. Using the Sharktuner in Autotune mode eliminated most of the problem except for a few cells where it max'd them at +128 but they were still lean and you could feel the stumble on crossing those cells. That's why I'm going to change the injector size setting down from 30 to 24 and re-tune from that. Heck, I probably should use 19 as a starting point as the car previously ran well on a stock LH chip prior to adding the IC and bumping from 5 to 6 PSI boost.

 

Bill-

Might I make a slight suggestion. Rather than adjusting from 30 to 24 etc... I would use the custom fuel injector setting and bump it up or down until you get a decent idle (on a warm engine). Then all you should have to do is tune for boost - that's the theory at least.

Don't forget to take a little timing out before you start tuning for the WOT fuel maps.

Oh, and feel free to call me on my cell up to 10pm Eastern in case I'm not on line on the XD16. 734-eight three seven - seven nine zero eight

 

The red area should have gone leaner, unless he was putting foot back into it a bit to try and keep it steady, in which case I could see the MAF going up but the RPS going down, and the AFR also getting slightly richer. As for the yellow circle, on my car, if I am decelling at all I will go into the 16's and 17's, so I think you're okay here. The only exception is toward the end where it looks like you down-shifted - the AFR remained high... I would have expected it to get rich for a little bit, but that could be due to driving styles.

 

Does the Sharktuner/ECU on the 928 have long term fuel trims that it "learns" over time? Many modern cars run roughly until they relearn the proper fuel/timing trims.

 

John and Andrew: I'll take your suggestion about just tweaking the injector size setting a small amount. I did read the manual, even more than once, but not everything sticks, so I ended up discovering it on the road.

Andrew: I see your interpretation of Craig's long cruise section being more or less OK. The RPMs are very slowly declining over most of the session, but as he appears to slow the decline and get more into the throttle, the MAF number rises, but the AFR gets leaner. Maybe 16 is OK with a soft pedal during a slow cruise, but he gets even higher and is complaining of hesitation, which is what I see in the few lean areas I have. He could still have an air leak as John suggests (check the plug in the MAF boot) or just need some fattening of the base map.

 

Thanks guys for all the input.
Bill: on the log 4 new intake that was turning onto a highway in 1st gear shifting at 4500 to 5000 rpm's to second then to third but as soon as I stopped accelerating I was anticipating stopping so there is some wierdness there that is probably more me lifting the pedal slightly than anything else.
The log 3 new intake is a better sample of holding the throttle steady, on that one I hit the record button as soon as I felt the stumble and then tried to hold it steady..but my instincts want me to add a little throttle everytime I feel it stumble because I know it usually brings the ratio back towards rich.

I pressurized the intake today and found the throttle body leaks at about 5 psi at the cable linkage...pretty big soap bubbles coming out of the spring close to the body....

The car holds a good 20 in hg at cruise so is a leak like that sucking in enough unmetered air to give me a constant 1100 rpm idle and a lean cruise AF ratio?

 

OK, here's a plot of 3 New Intake. I added the O2 sensor, which is way positive at the beginning. John needs to help interpret this, but I think it means the O2 sensor is signaling to lean the mixture. But, you're already above stoich. I would expect the O2 sensor to be at worst slightly negative here or do I have that backward, John? Regardless it should not be way positive or negative if the tune is correct. Anyway, you go slowly but progressively leaner and the O2 sensor zeroes out.

So, is this an O2 sensor problem? Is the LH seeing a different AFR signal than the Sharktuner? In other words, is the wideband and the LH narrowband source in disagreement? Otherwise I don't know why your O2 sensor is so strongly positive at AFR at or slightly above stoich. Whatever it is, this does not look like a good state of tune.