Cold start idle tuning

[Holden202T]

well you may be able to get them right with enough time spent with the stuff VL400 refers to but yeah i reckon if its not unhappy warming up its ok .. you can always richen the cold afr offsets if you need to so its happy, i guess you never saw what was being commanded and actual but it always worked hey

[jon]

You are 100% right there. As long as you turned the key and it started first kick and idled reasonably smooth the settings where perfect. Since adding the wideband it has opened up a whole new can of worms. What the engine is doing and the sensors reading can be 2 completely different things. At this point the engine starts and runs good from cold to warmed up so I think it maybe time to move on and start taking it for short drives to tune the VE table in the other areas besides idle.
Thank you to all that have put input into this post. I could not have got this far if it wasnt for all your help!
Thank, Jon

[Holden202T]

no worries mate, and it is good you are actually taking notice of the sensors and making sure you know whats what.

its a good idea to get a feel for whats normal inside the ECM, makes it alot easier to spot issues if/when they arise.

[vlad01]

just dug this thread up, been playing around with the tuning. all seems pretty good so far, though I noticed for the first 10 min or so with lower engine temps the ECU detects knock just about everywhere from light acceleration and up and pulls a few degrees.

Once reaching coolant temps of about 75ºC all the knock goes away completely, none to be detected anywhere on the map as far as I can see.

is this likely to be the cold start enrichment not being set correctly? I have feeling its running too lean when cold although I haven't got a WB on it yet to confirm.

any ideas? I will soon get a log with this.

Also how much is too much for the BLM (LTFT)? some areas show as much as 10%. most are pretty good only few % off.

[Holden202T]

It could just be that the engine is rattly because its clearances aren't up to spec, I wouldn't worry too much about that cold stuff, and if its not knocking when hot then it shouldn't be when its colder, unless the timing is majorly different or the fuel mixture.

[vlad01]

It could just be that the engine is rattly because its clearances aren't up to spec, I wouldn't worry too much about that cold stuff, and if its not knocking when hot then it shouldn't be when its colder, unless the timing is majorly different or the fuel mixture.

could be timing chain, I believe its stretched. the engine does show symptoms of it, litter noise in certain rpm ranges and erratic behavior at rpm associated with the lifter rattle.

once warmed up it isn't as bad.

there is this loud arrooogaaa screech sound upon start up quite a lot of the time at the top end. Have no idea what that is, but its been there since day 1 of this engine.

[Holden202T]

just part of its character

[vlad01]

just part of its character

yeah thats why I like ecotec better, they dont get this weird noises and vibrations like pre ecotec does in even their early ks

[Holden202T]

no they just have a tendancy to crack the heads !!! i'd personally stick with the pre ecotec.

[Jayme]

not everybody had a super string of bad luck man ive personally never seen an ecotec crack a head.... tho I saw one spit a rod onto the road a few weeks back could hear a bearing grabbing, so we did what any self respecting owner woudl do..... we disabled the rev limiter and held the throttle flat in first with the brake on till either hte tyre popped or the engine did... the engine popped first hehe