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Question about tps threshold to double AE term.

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Old Jul 23, 2004 | 12:28 AM
  #1  
dimented24x7's Avatar
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From: Moorestown, NJ
Car: 88 Camaro SC
Engine: SFI'd 350
Transmission: TKO 500
Axle/Gears: 9-bolt w/ 3.23's
Question about tps threshold to double AE term.

I had a question about the following in the code for my ecm:

Code:


;
;-Double AE term if enough %TPS
;
        LDAB    L0043		;%TPS
        CMPB    LD1DA		;128, 50% tps
        BLS     LD666		;Bra if tps is <=
;
        ASLA 			;AE x2   
        BCC     LD666		;Bra if no overflow
;	
        LDAA    #$00FF		;Clr overflow
        BRA     LD666		;Bra to save
Seems like its been so long I cant even remember but the last time I drove my car, after having fixed the ign. problems, I noticed that after so much off idle opening it seemed to develop a bit of a stumble. Could it be due to this? It seems like this could add a whole mess of AE if the throttle was suddenly opened. I assume its intent was to provide additional AE at high load when the throttle was further opened?
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Old Jul 23, 2004 | 07:26 AM
  #2  
Grumpy's Avatar
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From: In reality
Car: An Ol Buick
Engine: Vsick
Transmission: Janis Tranny Yank Converter
Re: Question about tps threshold to double AE term.

Originally posted by dimented24x7
I noticed that after so much off idle opening it seemed to develop a bit of a stumble. Could it be due to this? It seems like this could add a whole mess of AE if the throttle was suddenly opened. I assume its intent was to provide additional AE at high load when the throttle was further opened?
Normally the PE enables are set really high so you need alot of AE to get the engine into PE. AE can decay out quickly, and is a good thing for mileage, but it can make fueling a hotrod a problem. Also, you can get to where you have so much AE that at the higher throttle openins, it forces the engine too rich temporaily, and allows for too much timing being present.

Small slow throttle openings should get you perfect accleration just using the VE table. As you work on quicker transistions, you can add AE, and lower the PE TPS enable. Least that's what Doc seems to be having good luck with. Then as you get further along break the AE into MAP vs TPS.

The code question I'll leave for others.
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Old Jul 23, 2004 | 11:48 AM
  #3  
dimented24x7's Avatar
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From: Moorestown, NJ
Car: 88 Camaro SC
Engine: SFI'd 350
Transmission: TKO 500
Axle/Gears: 9-bolt w/ 3.23's
After pretty much doubling the MAP AE stuff and adding in more TPS AE in the first two cells, I got the AE to the point where it was acceptable over most conditions. A sudden slam to the floor, opposed to jsut stopping part way, would mean that it would stumble for a sec before it cleared up and got going. I wasnt running much timing, jsut what I needed to get the motor to run decent. hmm... maybe when I get the car running try maxing out the threshold so it doesnt double the term and see if it helps any?
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Old Jul 23, 2004 | 11:56 AM
  #4  
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From: In reality
Car: An Ol Buick
Engine: Vsick
Transmission: Janis Tranny Yank Converter
Originally posted by dimented24x7
maybe when I get the car running try maxing out the threshold so it doesnt double the term and see if it helps any?
Yes.
And in some apps it really is hard to tune around the converter/ drivetrain inertia. While it's only 6" in diameter, trimming 4 lbs. off my crank pulley made a noticeable difference in the amount of AE I had to run.
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