Chip programming thought experiment
Thread Starter
Burning Brakes
Joined: Feb 2000
Posts: 1,247
Likes: 2
From: Parker, Colorado, USofA
Chip programming thought experiment
(Since this got ZERO reponse on the VN)
I've found that when I disconnect the battery on the Sled (Superram, 383, yadda yadda), the ECU and custom programmed chip take awhile to 'relearn' the parameters that make the car perform well off the line and at part throttle. Thinking that it might have been a flaw in the programming, I was making a mental note to see what parameters it WAS using and have them burned in as the default values.
Then I thought about it a bit longer and wondered if the problem was that 48mm throttlebody I still have, instead of the 58mm throttlebody I specified in the custom chip order form. It was a logical choice as I'm planning on swapping out the TB pretty soon and didn't want to have an additional chip burnt (at $350+ shipping a pop.)
I'm also having a minor cold start issue where the motor doesn't light off immediately, making the exhaust REALLY rich...oh yeah, and the motor hunts at idle...think they're related too?
I've found that when I disconnect the battery on the Sled (Superram, 383, yadda yadda), the ECU and custom programmed chip take awhile to 'relearn' the parameters that make the car perform well off the line and at part throttle. Thinking that it might have been a flaw in the programming, I was making a mental note to see what parameters it WAS using and have them burned in as the default values.
Then I thought about it a bit longer and wondered if the problem was that 48mm throttlebody I still have, instead of the 58mm throttlebody I specified in the custom chip order form. It was a logical choice as I'm planning on swapping out the TB pretty soon and didn't want to have an additional chip burnt (at $350+ shipping a pop.)
I'm also having a minor cold start issue where the motor doesn't light off immediately, making the exhaust REALLY rich...oh yeah, and the motor hunts at idle...think they're related too?
Race Director
Joined: Mar 1999
Posts: 12,578
Likes: 237
From: Bartlett Illinois
Re: Chip programming thought experiment (RocketSled)
sounds like a Minimum Air issue at idle.. have you reset it lately? IS the IAC working Properly? With my latest ECM swap in my car I found at Idle it would hunt and almost stall, I bumped the Min Air idle up and it seems to be fine.
Race Director
Joined: May 2001
Posts: 14,165
Likes: 9
Re: Chip programming thought experiment (RocketSled)
If it's running rich it could be because of the 48 mm, expecting more air then it's getting. However the IAC is the same between the two TB's and that's where most of your idle air will be coming from anyway. Who knows. Best of luck to you.
[Modified by Nathan Plemons, 8:22 AM 5/9/2002]
[Modified by Nathan Plemons, 8:22 AM 5/9/2002]
Thread Starter
Burning Brakes
Joined: Feb 2000
Posts: 1,247
Likes: 2
From: Parker, Colorado, USofA
Re: Chip programming thought experiment (-=Jeff=-)
sounds like a Minimum Air issue at idle.. have you reset it lately? IS the IAC working Properly? With my latest ECM swap in my car I found at Idle it would hunt and almost stall, I bumped the Min Air idle up and it seems to be fine.
Is the Min Air Idle adjustable with an 89 ECM?
Race Director
Joined: Mar 1999
Posts: 12,578
Likes: 237
From: Bartlett Illinois
Re: Chip programming thought experiment (RocketSled)
Is the Min Air Idle adjustable with an 89 ECM?
