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TK? Getting ready to burn my first EPROM (long) by JazzMan
Started on: 08-08-2003 01:32 AM
Replies: 8
Last post by: TK on 08-10-2003 12:28 PM
JazzMan
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Report this Post08-08-2003 01:32 AM Click Here to See the Profile for JazzManClick Here to Email JazzManSend a Private Message to JazzManDirect Link to This Post
I've done some logging with WinALDL while driving around a few miles of mixed road conditions. Looking at one file in the format of date_time_BLM.txt that WinALDL saved, at the Wide Correction 10, I see that the correction suggested is pretty solidly in the 1.132-1.141 range, which seems to indicate that I need to bump fuel by around 13.5% on average. This seems to coincide with the 14% increase in displacement that I got when I rebuilt my 2.8 as a 3.2 in my Formula 5spd.

So, using GME PRO with the turbo .epe file that came with it and an image that I pulled off of my spare ECM's EPROM I'm ready to start editing. It seems that I want to modify the BASE PULSE VE - RPM VS MAP table by increasing the values by 13.5%. I also want to increase the EGR by about the same amount in order to reduce the slightly higher than desired NOx that I measured on my last test, would that be done in the BASE PULSE FOR EGR FLOW RATE (F28A) table? I've had a slight tip-in hesitation since I built the motor that I would equate to an undersized accelerator pump on a carb'd vehicle, so would I change this via TPS% THROTTLE ANGLE CHANGE FOR POWER ENRICHMENT?

To address the lean drop that I'm getting in open loop I want to bump the fuel up about the same percentage in the COLD ENGINE AFR VS COOLANT AND MAP table, sound about right?

I don't yet have a WB O2 or access to a dyno for cost reasons, though I can partly simulate a dyno with some of the long, steep hills I've got in a few places around here. I'll be monitoring my O2 sensor with a Fluke 87, it has a fast analog "needle" on the LCD and an excellent averaging function. I can change a chip out in under 5 seconds with the ZIF mod that I did, so if I detect any problems I can revert to stock.

Does this sound like I'm on the right track?

Another thing that I'd like to do is back the part throttle advance off a few degrees to see if I can alleviate the pinging that I get on less than 93 octane fuel, that's assuming that the extra EGR and slight fuel adjustment don't take care of it. I desparately want to run cheaper fuel. Looking at the 1 BAR table it looks like the ECM commandsup to 48 degrees depending on the MAP and RPM, yikes!

Anyway, I'd appreciate any input and advice that anyone could throw my way.

Thanks!

JazzMan

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Report this Post08-08-2003 07:52 PM Click Here to See the Profile for JazzManClick Here to Email JazzManSend a Private Message to JazzManDirect Link to This Post
Just a bump
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Report this Post08-09-2003 12:20 PM Click Here to See the Profile for TKSend a Private Message to TKDirect Link to This Post
 
quote
Originally posted by JazzMan:

I've done some logging with WinALDL while driving around a few miles of mixed road conditions. Looking at one file in the format of date_time_BLM.txt that WinALDL saved, at the Wide Correction 10, I see that the correction suggested is pretty solidly in the 1.132-1.141 range, which seems to indicate that I need to bump fuel by around 13.5% on average. This seems to coincide with the 14% increase in displacement that I got when I rebuilt my 2.8 as a 3.2 in my Formula 5spd.

So, using GME PRO with the turbo .epe file that came with it and an image that I pulled off of my spare ECM's EPROM I'm ready to start editing. It seems that I want to modify the BASE PULSE VE - RPM VS MAP table by increasing the values by 13.5%. I also want to increase the EGR by about the same amount in order to reduce the slightly higher than desired NOx that I measured on my last test, would that be done in the BASE PULSE FOR EGR FLOW RATE (F28A) table? I've had a slight tip-in hesitation since I built the motor that I would equate to an undersized accelerator pump on a carb'd vehicle, so would I change this via TPS% THROTTLE ANGLE CHANGE FOR POWER ENRICHMENT?

To address the lean drop that I'm getting in open loop I want to bump the fuel up about the same percentage in the COLD ENGINE AFR VS COOLANT AND MAP table, sound about right?

I don't yet have a WB O2 or access to a dyno for cost reasons, though I can partly simulate a dyno with some of the long, steep hills I've got in a few places around here. I'll be monitoring my O2 sensor with a Fluke 87, it has a fast analog "needle" on the LCD and an excellent averaging function. I can change a chip out in under 5 seconds with the ZIF mod that I did, so if I detect any problems I can revert to stock.

Does this sound like I'm on the right track?

Another thing that I'd like to do is back the part throttle advance off a few degrees to see if I can alleviate the pinging that I get on less than 93 octane fuel, that's assuming that the extra EGR and slight fuel adjustment don't take care of it. I desparately want to run cheaper fuel. Looking at the 1 BAR table it looks like the ECM commandsup to 48 degrees depending on the MAP and RPM, yikes!

Anyway, I'd appreciate any input and advice that anyone could throw my way.

Thanks!

JazzMan

This would be better done in an email, but ....

First, 1 bar application?

I don't mess with the VE tables unless there are large holes or hills in the BLM. Usually, a displacement change causes an across the board shift in the BLM so I scale the BPW and BPW EGR by that shift (based on a BLM reading at a steady throttle at 60 MPH). Then I'll look at the BLM's in different conditions and decide if I need to tweak the VE tables. A BLM of 120 to 136 is fine. The limits are way beyond that anyway.

For NOX, scale the rest of the EGR BPW table by the same amount, then increase the EGR duty cycle. Just be prepared to change the EGR spark adder. Also cats can affect NOX.

For a tip-in problem, does it hesitate when you only change the throttle position slightly or when you stomp it? AE is the pump shot use to handle throttle changes (vs throttle stomps). The TPS Delta (change) is the enable for it. It might enable at the right time, but not with enough fuel. If you notice, they get the engine into AE and PE very early (compared to other cars). I would think the AE amount (not enable point) is the problem. I drive around and feather the throttle up and down. If it sags, I know I need more AE or I need to reduce the EGR flow.

Lean drop in open loop. Again, is this steady state? Samll TPS changes? or WOT? Disconnect the O2 and go for a drive. Does it go away?

Assuming a 1 bar map, the advance is normal for 87 octane unless you increased the compression ratio. Part throttle ping is usually a sign of too much advance with the EGR open. You might try backing off the EGR spark adder first and then dropping the spark table in the areas where it's being affected. I'm at a loss as to why calibrations for 87 octane are pinging on 93.

Smooth out the adjacent areas so there are not big transitions. 48 degrees is nothing really during cruise (low engine load).

TK

[This message has been edited by TK (edited 08-09-2003).]

[This message has been edited by TK (edited 08-09-2003).]

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Report this Post08-09-2003 05:58 PM Click Here to See the Profile for JazzManClick Here to Email JazzManSend a Private Message to JazzManDirect Link to This Post
 
quote
Originally posted by TK:

This would be better done in an email, but ....

First, 1 bar application?

No, normally aspirated. The .epe file is for turbo boosted applications.

 
quote
Originally posted by TK:
I don't mess with the VE tables unless there are large holes or hills in the BLM. Usually, a displacement change causes an across the board shift in the BLM so I scale the BPW and BPW EGR by that shift (based on a BLM reading at a steady throttle at 60 MPH). Then I'll look at the BLM's in different conditions and decide if I need to tweak the VE tables. A BLM of 120 to 136 is fine. The limits are way beyond that anyway.

I didn't see any tables that refer to BPW (presumably Base Pulse Width WRT injector timing?)

 
quote
Originally posted by TK:
For NOX, scale the rest of the EGR BPW table by the same amount, then increase the EGR duty cycle. Just be prepared to change the EGR spark adder. Also cats can affect NOX.

I'm starting to think I have the wrong software for this, or at least the wrong .epe file for GMEPRO.

 
quote
Originally posted by TK:
For a tip-in problem, does it hesitate when you only change the throttle position slightly or when you stomp it?

Both. The problem is worse when the engine is cold, and worse when the air temperature is colder such as over the winter. After it goes into closed loop the problem reduces in severety but never completely goes away. I've learned to feather the clutch when shifting so that the car doesn't lurch as I apply throttle. It's only one lurch, but it's still a big one. At higher RPMs I can still feel a little hesitation whenever I change throttle position.

 
quote
Originally posted by TK:
AE is the pump shot use to handle throttle changes (vs throttle stomps). The TPS Delta (change) is the enable for it. It might enable at the right time, but not with enough fuel. If you notice, they get the engine into AE and PE very early (compared to other cars). I would think the AE amount (not enable point) is the problem. I drive around and feather the throttle up and down. If it sags, I know I need more AE or I need to reduce the EGR flow.

Lean drop in open loop. Again, is this steady state? Samll TPS changes? or WOT? Disconnect the O2 and go for a drive. Does it go away?

Basically, when the entine is cold it will idle ok, though it tends to hunt between 800 and 1100, but as soon as I apply throttle the engine will want to stall. The faster I apply throttle, or the lower the initial RPM when I apply throttle, the bigger the power drop. In fact, for about the first minute or so after starting the engine if I attempt to use throttle at all it will almost stall. I have to gradually apply throttle to bring the RPMs up in order to get enough inertia in the rotating assembly to get the car going when I release the clutch. Once firmly in gear if I apply throttle the engine will sort of die, then buck hard as it accelerates. This occurs each time I apply throttle, and one it goes into closed loop much, but not all, of this goes away.


 
quote
Originally posted by TK:
Assuming a 1 bar map, the advance is normal for 87 octane unless you increased the compression ratio. Part throttle ping is usually a sign of too much advance with the EGR open. You might try backing off the EGR spark adder first and then dropping the spark table in the areas where it's being affected. I'm at a loss as to why calibrations for 87 octane are pinging on 93.

I am to re: the pinging. The engine had no symptoms of detonation before the rebuild, even though the EGR tube was completely separated at that point. My only theory is that the EGR amount is too low for the increased displacement. According to the specs the CR should have actually decreased with the 3.2 rebuild as the 3.1 pistons are 8.5 vs the old 2.8 pistons being 8.9.

 
quote
Originally posted by TK:
Smooth out the adjacent areas so there are not big transitions. 48 degrees is nothing really during cruise (low engine load).

I'll send you an email to the address in your profile. I'm really thinking that either I'm missing a huge chunk of understanding of the basics here or I've got the wrong software.

JazzMan

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Report this Post08-09-2003 08:02 PM Click Here to See the Profile for TKSend a Private Message to TKDirect Link to This Post
The EPE files are for both. Anything that is listed with the word (BOOST) means it's a parameter that is usually different on a turbo engine from an NA engine, but it still matters.

I did this to flag people to the cals that are specifically changed from the NA values.

Check your email.

TK

[This message has been edited by TK (edited 08-09-2003).]

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Report this Post08-09-2003 10:26 PM Click Here to See the Profile for RaydarClick Here to Email RaydarSend a Private Message to RaydarDirect Link to This Post
James,

Or you could just get an adjustable FPR, and crank up the pressure.

Sorry. Just kidding.
Best of luck. You're a braver man than I.

------------------
Raydar

88 3.4 coupe. 17s, cut springs 'n all.

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Report this Post08-10-2003 02:14 AM Click Here to See the Profile for TKSend a Private Message to TKDirect Link to This Post
 
quote
Originally posted by Raydar:

James,

Or you could just get an adjustable FPR, and crank up the pressure.

Sorry. Just kidding.
Best of luck. You're a braver man than I.


I prefer to think of it as running blindly into the whirling blades of life!

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Report this Post08-10-2003 10:25 AM Click Here to See the Profile for JazzManClick Here to Email JazzManSend a Private Message to JazzManDirect Link to This Post
No kidding. I feel like I'm on the verge of running the gauntlet in Galaxy Quest, you know the scene where Sigourney Weaver said "Screw this" but when you look at her lips the word she actually used starts with an "f".

JazzMan

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Report this Post08-10-2003 12:28 PM Click Here to See the Profile for TKSend a Private Message to TKDirect Link to This Post
F....?

Fa
Fe
Fi
Fo
Fu
Fy
Fw....?

Thinking.....

That was a funny movie! Guy Fleegman was the star.

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