my car pulls timing on knock too, it is a factory boosted PCM, but It is completely remapped to work with the turbo and most of the factory adders and whatnot have been 0'd out or disablesd.
I'm just talking about some basics, things will definitely vary from car to cra, but things to shoot for, well a boosted 4 banger is a boosted 4 banger.
2006 cobalt (no more turbo)
m62 2.7 pulley, E85, 79lb/hr injectors, 4-2-1 longtube header, airbox mod, stock catback
1998 Trans am 5.3 iron block 317 heads 88mm turbo e85 105lb/hr injectors, twin 255's.... build in progress
2014 wrx mild tune 18psi pump gas
You are correct.... If he had the 2000+ Reflash it would "read" boost, but due to his being a 99, its Alpha N (TPS based fueling)... I plan on taking a look at the file later(at work w/o HPT installed on this PC....)Originally Posted by tnsyty
P&P Tuning
ah yeah forgot about that alpha N crap.
my bad.
2006 cobalt (no more turbo)
m62 2.7 pulley, E85, 79lb/hr injectors, 4-2-1 longtube header, airbox mod, stock catback
1998 Trans am 5.3 iron block 317 heads 88mm turbo e85 105lb/hr injectors, twin 255's.... build in progress
2014 wrx mild tune 18psi pump gas
Thanks for the help guys, I'm beyond frustrated right now with the car... I thought I had things a bit better but while doing some cruising tonight the car stalled on me numerous times... the rpms still want to drop very slowly but now when the car comes to a stop the rpms drop and the car stalls unless I catch it... I've got no freaking clue about this coastdown or DFCO stuff
Occasionally when i first upload a tune to mine, it will do the exact same thing. It usually clears up in a few hours.Thanks for the help guys, I'm beyond frustrated right now with the car... I thought I had things a bit better but while doing some cruising tonight the car stalled on me numerous times... the rpms still want to drop very slowly but now when the car comes to a stop the rpms drop and the car stalls unless I catch it... I've got no freaking clue about this coastdown or DFCO stuff
'92 Typhoon (GM crate engine, TD06H, diacom, 19 psi) needs tune
'98 corvette. 6speed (12.79@110)
'04 Cavalier. ecotec 5speed dailydriver. body kit. 35mpg. (10.15@69 1/8th) slow
Here is a log of my idle and also my latest tune... the car seems to go very lean as soon as I step on the gas... The car hesitates pretty badly as soon as the throttle is touched. Any ideas? Thanks so far for the help guys I really do appreciate it.
BumpIf anyone needs any other logs just let me know and i'll do my best to get them for you.
anyone have any ideas at all? I will seriously pay someone to help me get this thing straightened out at this point. If you're interested just shoot me a PM. I just can't seem to get this figured out
How did you come up with your injector constant? I just did some quick calculations (without knowing your exact stock constant) and using your 770's and I came up with .07xxx ., you currently have .12850 .. If your constant is wrong or miscalculated you might as well start over as this will/can cause many issues.....
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truth right there.
We had an issue with my friends cavi because he decided to switch to cobalt ss/sc injectors for some reason
2006 cobalt (no more turbo)
m62 2.7 pulley, E85, 79lb/hr injectors, 4-2-1 longtube header, airbox mod, stock catback
1998 Trans am 5.3 iron block 317 heads 88mm turbo e85 105lb/hr injectors, twin 255's.... build in progress
2014 wrx mild tune 18psi pump gas
you know, my car does that also. ill be cruising and go to slow down and downshift from 3rd to 2nd and then use the brakes from there out and when i come to a stop the rpms will hang from 1200 to 1300ish and i have to blip the throttle to correct it. its kinda annoying. now when i spray nitrous the rpms will hang from 2k up to 2500 and thats the most annoying and blipping the throttle will NOT correct that. i basically have to shut the car off and relearn the idle by driving it for like 20 miles or so. anyone understand what im talking about? any known fix for that? i have a 01 z24 with the mp45 supercharger kit and ss/sc 36lb injectors, 2.6" pulley, intake, aluminum stock size crank pulley, header back 2.25" exhaust, msd coil swap, 2 stage colder plugs, zex 55 shot wet kit, stock internals with 168k miles on it. I also have a coolingmist meth injection kit. currently seeing 7psi but when im spraying nitrous i see 8psi.
I have(along with others I know) have ran into very similar situations. There have been times that I have to literally reflash my daily driver (Supercharged Z24) just so it does not idle at 1800-2500 rpm. I am convinced there are other tables that we are not seeing and probably won't.I mean hell, we don't even have a commanded AFR (we do for PE, but thats it) ....
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well i have my PE delay rpm set at 2700 rpms. we corrected the injector constant for the ss/sc injectors and it runs smoothly but after spraying nitrous like 2 or 3 times it will idle all wacky. i dont have to reflash the car to get it back to normal idle but it takes a while to do it on its own. now if i dont spray then its fine. it was also acting like this before i put the cobalt injectors, like on the kits 310cc injectors so i know it has nothing to do with changing the injectors. im wondering if my coast down idle needs adjusted..
I beleive I tried using the .07xxx constant in the beginning but the car would not run at all at that constant. I'm open to trying it again though and building out an alternate tune at this point. At this point i'm just incredibly frustrated with the car
What exaclty do you mean by it would not run? Did it run poorly or not start at all? What was your stock injector constant? Also, what fuel pressure you running?I beleive I tried using the .07xxx constant in the beginning but the car would not run at all at that constant. I'm open to trying it again though and building out an alternate tune at this point. At this point i'm just incredibly frustrated with the car
P&P Tuning
One aspect of black06g85's car (and other Cobalts as well) is its 2.5 bar MAP OS, and its MAF, two things that the Cavalier-Sunfire did not share. As such, I'm a bit lost as to how folks are providing boost-proportional fueling on such cars using HPT alone.
Additionally, it's possible that such large injectors cannot be well-controlled in decel, as they'd be around 3-4 times stock size. I don't know if the Cav-Sun PCM can hang with that at low flows.
Very turo Bill.... I have been using a modified LD9 SC Reflash on the 2000+ LN2 (2200) and have had great success with it.... On the Alpha N (Pre 2000+ and Eco) I have been able to get great results also, but it takes more time (as it does not reference boost).... Obviously this is not the most ideal way to do it, but most can't afford a standalone and there seems to be minimul AFR spikes (if they do happen they would be rich, but very, very slight).... Can only work with what we are givin...BTW, Awesome job to you and Adam for finally hittin the 10's in the Sunfire
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The car would start but immediately stall out, it acted too rich at that constant. My stock injector constant is .20250 and i'm running right around 43psi fuel pressure.
I'm going to attempt using the .07xxx constant again tomorrow and see what I can get from it.
As far as the tuning on the pre 2k alpha-n ecu's it's not fun by any means but it should be doable from what I see... I had the car running nearly perfect at about 20psi with these injectors but once I stepped up the boost and ended up having to move my VE offset is where my issues came into play.
Thanks again for all the help everyone I really do appreciate any and all suggestions.
Another piece to the puzzle... hen you changed your offset, did you subtract that same amount from all the tables?
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Yes I pulled the idle, single, and double fire tables down to where they were prior to the VE offset being moved. The High RPM tables were the only ones that were moved using the higher offset.
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