KR elimination

[Allmachtige]

For all those tables you posted I left what Intense put in there; all 640's.

EDIT: Make that 639.98. Forgot to move that decimal.

[99ssei]

As I swapped out my 103s to 104s (as a test), I noticed a plastic hose that connects from the FPR, then T's just underneath the SC snout (connects to the UIM), then continues on to the back of the engine, between the alt and SC housing, #2 FI / Rail and then into some solenoid that is mounted behind the EVAP purge solenoid (above spark plug # 4 & 6).
This hose, is plastic with rubber hose fittings, however, the plastic hose that goes between the Alt and the SC housing was broken and it looks as though whom ever worked on it before, replaced it with a rubber vaccum hose. The rubber hose starts almost exactly between the alt. and SC housing and goes all the way back to the solenoid (with two openings - Looks like an F). I'm wondering if the 1/2 plastic hose / 1/2 rubber hose might be causing an issue. Went to the dealership and the part has been discontinued. Even VitangeParts.com doesn't carry it. The part # is 24507328. I'm going to hit the junk yard tomorrow and see if they have one.

[Allmachtige]

Pics? I kinda followed you for awhile then the words scrambled together.

I'm pretty sure I know what your talking about, but pics help a lot. Could have been a major problem if it what I think.

[99ssei]

[99ssei]

Curious....can anyone with SLPs take a look at their front headers and let me know if pipe #1 and #3 are touching as the run along side of the motor (before the collectors) ?


I could not get a piece of paper between these pipes so I know they are definitely touching. If they vibrate enough, is it possible this might trigger the KR sensors?

[BillBoost37]

Touching is normal

[Allmachtige]

Replace that vacuum line going around the supercharger. I'll try to dig up the schematic at home with the part number, but any GM dealer parts department with any desire to help will give you the same printout I have.

[99ssei]

Ordered part # 24507328 from a dealership in New Castle, PA. Should see it in 3-5 days. $33 + Shipping.

[2000Silverbullet]

Ya, those plastic lines do not seal when they break. You can't just slide a hose over them to connect. It won't seal.

[99ssei]

Ya, those plastic lines do not seal when they break. You can't just slide a hose over them to connect. It won't seal.

So, you think that might be a cause?

[2000Silverbullet]

Well I know if you lose pressure or vacuum, that will affect the AFR and therefore you might not be running stoich.

[99ssei]

WTF!?!
What happened to all of today's posts?!?!

I've lowered my IFR @ 100 kPa by 1% to get O2s up a little.
I was wondering if this table might be affecting anything. I'm commanding 11.8 in PE mode, will this make a difference?

[PDXGTP]

WTF!?!
What happened to all of today's posts?!?!

I've lowered my IFR @ 100 kPa by 1% to get O2s up a little.
I was wondering if this table might be affecting anything. I'm commanding 11.8 in PE mode, will this make a difference?

All that's going to do is add timing under ideal conditions, that is the reason you can be commanding 25* of timing but actually the table is at 17* High octane. Usually you will only use this when the engine is cold and not WOT.

Personally I would not adjust your IFR's in efforts to adjust O2's because that will skew the entire tune.
Set those to 36 or the scaled table and leave it because the copmputer needs to know what the actual flow rate of the injectors are. if you have 42# injectors, what i like to do is set the IFR to 42.5 all the way across because we have a return fuel system.
If you do not have a return fuel system then I'd use the scaled table that would go from 36.0 to 38.2 or whatever.
When we have forced induction the injectors have to spray longer to get enough fuel into the chamber because it has to fight against the positive pressure of the cylinder heads. The greater the pressure the longer the injector needs to spray to meter the proper amount of fuel.
I set this before tuning and don't touch it during tuning.

[superchargedSSEi]

Sort of related...but is the AFR spark correction table based off of the base PE AFR, or the commanded AFR after the PE vs time table and the like are taken into consideration (hope that makes sense)? Don't have access to it with my software/pcm so I don't have any experience with it.

[Foghorn]

We've already been through the explanation of AFR Spark a few times, no?

As for the IFR, well, the 100 kPa tweak is a quicker route, versus playing with the MAF, to fueling the engine 'correctly' while one is trying to discern the effect of Torque Management.

All the tables interact, it just happens that IFR interacts with fewer tables unlike the MAF, GFS and MBTS.

Cheers,

[99ssei]

I have stock injectors and I believe the return fuel system (3 fuel lines along the the frame - 1 to, 1 back and 1 evap, right?)

[PDXGTP]

I remembered one of the limiters we spoke about.
It was Engine/Fuel Control/Fuel Cut Off/ Cutoff PRM vs. Gear "Normal"
Basically you need to make sense of this choice.

IMHO, this is more important then the spark limiter for RPM's because you always want the cylinder to have fuel .. if it has spark at high rpms .. or nothing at all.
I suggest if you have stock valve springs you need to decide on what RPM you can rev the engine. I have no recommendation. sorry.
If you have the common Comp Cams 105's valve springs.. which I love.. rev it up to 7000 RPM's. Trust me, you'll want to do it as often possible... but always at the track.

[99ssei]

I remembered one of the limiters we spoke about.
It was Engine/Fuel Control/Fuel Cut Off/ Cutoff PRM vs. Gear "Normal"
Basically you need to make sense of this choice.

IMHO, this is more important then the spark limiter for RPM's because you always want the cylinder to have fuel .. if it has spark at high rpms .. or nothing at all.
I suggest if you have stock valve springs you need to decide on what RPM you can rev the engine. I have no recommendation. sorry.
If you have the common Comp Cams 105's valve springs.. which I love.. rev it up to 7000 RPM's. Trust me, you'll want to do it as often possible... but always at the track.

I have all stock valve train. My Cuttoff RPM vs. Gear is set at 6200
My shift points are set at 5500, 1->2 @ 44, 3->2 @ 83mph.

[99ssei]

Due to the server issues we had, my earlier posts are not here. I've made the alt. mod on Tuesday night (http://www.bonnevillepro.com/forums/vie ... =36&t=5856), which puts 14v to the system (instead of 13.3). I've also replaced the FPR hose. Here's the pic of what was taken out.


Back to tuning...change of direction (like a gazelle), on Foghorn's suggestion, we're putting the IFR back to almost stock (100 kPa was only cell changed - now it's @ 37.24835 - stock was 38.4). Original IFR @ 100 kPa was 32.94920 (14.2% from stock). MAF table to PE section is under construction. Starting with increasing 7000 hz by 1%, 7125 2%, 7250 3%, 7375 4%, 7500 hz and up 5% increase. Will be writing changes to PCM, resetting fuel trim and adjusting MAF for PE over the next few days. Hoping to have PE portion of MAF adjusted by Monday.

[99ssei]

Two questions...when does the PCM choose between the High Octane or the Low Octane timing tables?

I'm seeing very low timing (5, 6, and 7's instead of the 10, 11, and 12's that the high octane table is set for) at WOT in PE. I've already zero'd out the PE adder vs. RPM vs. time. Can anyone tell me what other tables affect the timing under WOT?