Hey Guys, I've got another problem here. When in open loop it runs great, Idles great, throttle response is really good and it has lots of power. Once in closed loop though it seems sluggish. When i put it into gear it will idle for about 15 seconds then the idle suddenly drops. It will stall if you dont nudge the pedal a little...after you nudge it, it will idle right back up and do it all over again a few seconds later. I'm getting a code 33 and the ses light comes on the goes right off again. Ideas?

16168625 ECM 6E

 

Code 33 = High Map, which means that you must have a larger than stock cam in your truck. What happens is the MAP rises from having a larger cam with increased overlap. With the lower than normal vacuum, the high map diagnostic will be tripped at idle. Once the MAP code is set, the PCM will run off of a Alpha N signal generated by the PCM code and the TPS. I bet the light goes off as soon as the engines RPM is brought up and held higher than idle for more than 15-20 seconds, mine always did. I only got the code 33 with the engine idling in gear and the A/C on. My cam was pretty big in my 305 too. 224/224 @ .050. I will assume that you are doing your own tuning.

EDIT- Just my two cents, but I would switch to the $0D code by switching to a $0D type of calibration.

This is the MAP error part of the calibration, addresses in the prom, etc.

;------------------------
; ERR 33
;------------------------
L4E4F FCB 10 ; 4% TPS limit
L4E50 FCB 156 ; 68 Kpa MAP Lmt
L4E51 FCB 50 ; 5 Sec's time Lmt
;------------------------
Then once the error is diagnosed, it reverts to AlphaN on this coding

; ERR 33/34
;------------------------
L4E56 FCB 218 ; 90.8 Kpa default MAP if not running
L4E57 FCB 112 ; 1.75 MAP default coef
; COEF * 64

;------------------------
; MAP DEFAULT BIAS vs RPM
;------------------------
L4E58 FCB 64 ; UPPER TBL LMT
;
; A/D RPM
; ---------------
L4E59 FCB 90 ; 90 800
L4E5A FCB 35 ; 35 1600
L4E5B FCB 7 ; 7 2400
L4E5C FCB 2 ; 2 3200
;------------------------

 

Fast, Its exactly as you said although mine will do it with the ac off too. It idles in P/N right around 60 - 62 map and from your cam specs i'm assuming yours idles pretty much in the same range too. I'm using tunercat as my editor.

 

Fast, this is probably better asked in another forum, but i'm using tunercat. What parameter would I change in that editor to prevent that code? Its definately as you stated and the SES light comes on as soon as the RPM drops to about 500 (right about where the stall routine kicks in also) I quess what I'm saying is i'm not really sure what to change to actually correct the condition. I understand the address and parameters somewhat of your reply but not really sure what to change.

 

I do not know how to add a parameter with Tunercat. If it were TunerPro, I have made my own definitions for it. With the Tunercat software, I would be lost.