I plan to run my nitrous off the egr control, like what's been done with the ebl. I need some help finding what disables the egr it in PE. I've searched through the code and I'm not finding anything specific. Does it just get skipped over in PE? What was done with the ebl?

 

The only thing I saw is enable EGR if TPS > X and EGR cycle duty!=0 and enable EGR if TPS > X and EGR cycle duty=0. None of those seem to help so look at the cycle duty table

It appears the EGR only operates between 800 and 2000 rpm and LV8 from 48 to 160. Outside that range I'm not sure what happens, I guess its disabled? Meaning once you get over 2000 rpm or over 160 LV8, it turns off.

If thats the case, then if you use the EGR line as a ground for the solenoid to activate it (Or the opposite as i'm not sure how the EGR works, I assume it sees voltage when its ON and the ecm grounds the pinout to allow voltage to EGR during ON) once you go over 2000 rpm the nitrous would come on? Which would be too early

Other way to do it is use TCC force lockup threshold MPH and set your solenoid to run off that converter lock up wire. Set the bin to lock at whatever mph is around 3000 rpm in first and spray away. 87_TA does this but he doesnt have a lockup converter when he did that, and now doesnt even have an auto trans but still uses TCC output for nitrous

 

The N2O in the EBL is another section of code. It was written specifically to handle a wet N2O system. With the EGR option flag selected, the EGR code/logic runs. When the EGR option flag is un-set, then the N2O code/logic runs.

RBob.

 

So I take it the egr code might not do what I need? Looking at the code it appears that once it's above 160 LV8 and/or 2000 rpm the ecm just uses the last entry in the table, like the other tables. From what I remember when I had the egr hooked up it would just hold whatever d.c. it was at before entering PE. There's 2 constants at LC0248 & LC0249 for minimum load & rpm the table starts at that I think I can use to move the table around, but would that require rewriting stuff elsewhere? Do these constants do what I think they do?

 

...

 

Anyone know if the constants at LC0248 & LC0249 will move the table like I think it will? For some reason I can't get the egr to do anything so I can't test this out quite yet.

 

I have the egr working again and the table can be moved like I thought, but I still can't find what's turning it off at wot...

 

I guess the better question would be how do I activate it at wot?

 

ACtivate it using the 165 code and EGR? Just not sure how that would work. Does the code ground the EGR to turn it off? Could you incorporate the ground for the nitrous switch 12v? I am not sure I see the advantage in trying to control the nitrous thru the ecm?

 

There are a couple of ways you can do it, depending upon how you want it to behave.

If you only want it to activate during PE, you can change the BNE to BEQ.

If you want it to activate independently of PE you can change the comparison bit to something that is never set (like bit 7 instead of bit 5, for example).

LDAA L0043 ; AF MODE WD
BITA #$20 ; b5, PWR ENR IS ACTIVE
BNE LDF45 ; BR IF NOT b5
; ... else

 

So I can control large shots without devastating my little motor. Well, not immediately anyway. The plan is to find out how much it will tolerate before it pops. I think an .08" jet should do it. Egr output is 12v pwm.

Ok, let's see if I can get this file reassembled... stupid dos. Is there an assembly program that doesn't use command prompts?

 

Well activating thru the ECM or activating through a WOT switch with a window switch as a back up safety shouldnt make a difference in engine longevity Keep the tune happy and it will live.

 

I would just use a hex editor to make the changes. No need to reassemble. You just need to find the appropriate address in your bin.

You can simply change the 0x20 to 0x80 to compare with bit 7 instead of bit 5 to be independent of PE.

You may also want to get yourself a solid state relay that can live with the duty cycle, if you don't already have one.

 

The sudden torq increase from a 200 shot is enough to break stuff . Which is why I need pwm.

Didn't think of the relay. Thanks. By the way this is $6E. I think I've found the right location to change, but it isn't labeled well. One of these...

; ... else
DEF6: LDAB L0036
DEF8: BITB #$20 ; b5
DEFA: BEQ LDF52 ; BR IF NOT b5
; ... else
DEFC: LDEFC LDAA L011A
DEFF: CMPA LC247 ; IF MAT < 151C, (304F) DISABLE EGR
DF02: BCS LDF52
; ... else
DF04: LDD LC245 ; ENABLE EGR IF TPS > 5.6% IF EGR DC <>
DF07: TST L0119 ; EGR D.C.
DF0A: BNE LDF0D

DF0C: TBA
DF0D: LDF0D CMPA L0083 ; TPS Ld Axis Var
DF0F: BHI LDF52
; ... else
DF11: LDAA L0044
DF13: BITA #$20 ; b5
DF15: BNE LDF52 ; BR IF b5
; ... else

 

With $6E, the line at DF13 is what you would want to change (assuming the addresses haven't been shifted by another patch).

A word of caution. $6E appears to make use of bit 7 of the AF mode word for start-up enrichment.

You may be better off changing the BNE at DF15 to a BEQ. (0x26 -> 0x27). This would have the effect of only enabling in PE mode, which probably makes more sense anyway for nitrous activation.

 

Changing it to BEQ works properly. I think I may need to add a 1st gear lockout though. It's alot of fun, but I can definately see a broken tranny from a downshift w/ nitrous active. If I can make it check C6E3: FDB $0047 ; 59 CARS MODE WORD bit 5 before nitrous use I can lock it out of 1st. I thought about doing automatic bottle opening at a certain throttle point too but decided against it. With my foot it would be gone in no time. I am going to use the maf burnoff to close the bottle at shutoff though.