How long for 'learn'
Thread Starter
Racer
Joined: Nov 2010
Posts: 460
Likes: 1
From: Oliphant Ontario
How long for 'learn'
Had severe idle issues on my 87 (but 90 MAP setup, complete)
Tore intake down for that and valve seals etc. It now idles great out of gear, maybe a tad high, 800 on tach but haven't plugged in to verify that RPM. However tried it in gear, idles down to close to correct, is smooth but hunts just a hair. Sooner or later will stall. Have only idled in gear for about 15 mins and it hasn't (can't yet) been driven.
Is this an issue? I have an 88 Cavalier years ago and it would take couple days after a battery disconnect to finally learn so I am not too worried but wanted to know if your experience is the same on a Vette. Only thing off base is the injectors, they work fine but I have no idea what flow they are. Stupid Venom injectors, they don't stamp them with a model. Only thing for sure is they are probably not 22's since Venom doesn't make a 22, likely 24's.
Thanks!
Tore intake down for that and valve seals etc. It now idles great out of gear, maybe a tad high, 800 on tach but haven't plugged in to verify that RPM. However tried it in gear, idles down to close to correct, is smooth but hunts just a hair. Sooner or later will stall. Have only idled in gear for about 15 mins and it hasn't (can't yet) been driven.
Is this an issue? I have an 88 Cavalier years ago and it would take couple days after a battery disconnect to finally learn so I am not too worried but wanted to know if your experience is the same on a Vette. Only thing off base is the injectors, they work fine but I have no idea what flow they are. Stupid Venom injectors, they don't stamp them with a model. Only thing for sure is they are probably not 22's since Venom doesn't make a 22, likely 24's.
Thanks!
Le Mans Master
Joined: May 1999
Posts: 6,514
Likes: 1,301
From: Windermere FL
On my 90 (MAP) it takes it only a few minutes to learn. I know this because when I replaced the stock injectors with a set of 30GPM ones, it ran like crap for a few minutes and then it figured it out.
Perhaps your IAC is dirty or needs to be reset or perhaps replaced? I know I have seen a procedure to reset the IAC - try a search. But I would clean it first. Only takes a few minutes.
Perhaps your IAC is dirty or needs to be reset or perhaps replaced? I know I have seen a procedure to reset the IAC - try a search. But I would clean it first. Only takes a few minutes.
Thread Starter
Racer
Joined: Nov 2010
Posts: 460
Likes: 1
From: Oliphant Ontario
IAC is functioning and cleaned. I haven't done a base idle yet but since the TPS is dead on for voltage and non adjustable on this unit I don't think that is it. I did clean the EGR as good as possible but after cleaning you could still suck a very small amount of air through it, knowing they are NLA I was hoping it was OK. May block the inlet to it for a bit and see if that makes a difference..
Thanks for the info, was hoping this computer was like the old Cavalier that took probably 20 stalls before it learned the idle, but only in gear like the Vette is doing. Will dig a little deeper into the issue based on your car learning that quickly.
Thanks for the info, was hoping this computer was like the old Cavalier that took probably 20 stalls before it learned the idle, but only in gear like the Vette is doing. Will dig a little deeper into the issue based on your car learning that quickly.
Melting Slicks
Joined: Feb 2006
Posts: 2,753
Likes: 15
From: backwoods upstate ny
takes 2-3 minutes for the ecm to get a 'good' o2 sensor input and go 'closed loop', then typ 10 min DRIVE at 'part throttle' with varying engine load/speed to approach 'correct' BLM's, another couple of hours under 'medium' conditions gets closer yet...ecm learning never stops.
with -727/-730 MAP ecms, no need to set TPS position as those ecm's 'auto-zero' if TPS signal is anywhere near correct (see 90+ SM for wild 'out of range' TPS voltages if MIL comes on)... most of these ecm's (not all, depends on calpak variant) also 'functional test' the EGR at constant throttle/~42 mph and will light MIL if EGR is non-responsive (aka, your 'blocking plate' installed)
with -727/-730 MAP ecms, no need to set TPS position as those ecm's 'auto-zero' if TPS signal is anywhere near correct (see 90+ SM for wild 'out of range' TPS voltages if MIL comes on)... most of these ecm's (not all, depends on calpak variant) also 'functional test' the EGR at constant throttle/~42 mph and will light MIL if EGR is non-responsive (aka, your 'blocking plate' installed)
Last edited by redrose; Feb 10, 2011 at 05:19 PM.
