eaglegoat

not enough info. what pcm? what platform is it in?

joecar

Do you get any DTC's...?

0ldtim3r

pcm i got from ebay.. its for a 2007 6.0 corvette its a 82 el camino the tranny is to a different pcm that i got from the same seller on ebay. it seems like i lose my tune because i lose alot power after i drive it for awhile.

0ldtim3r

the only code i was getting was a p0741 i changed out the solenoid already...the knock sensors are deleted so if its giving other codes i dunno.....i did break my driveshaft recently though i dunno if it being out of balance has anything to do with it..

joecar

There are various MAF/MAP/ETC sanity envelope tables, one or more of these tables is being exceeded, so ECM closes throttle to stay safe.

0ldtim3r

ok so i would i go about to fixing this issue? i dont think the local tuners even know what those are... thxs for the info joe

RedTA02

Ive been working on my car myself since i bought it in 2005. Its been a fun learning process. In 2008 i found a "free hp mod" forum on here, i de-screened / Ported MAF and throttle body; installed, LT headers, k&n cai and a diablo tuner. At the time i didnt know any better and installed the rear o2s because they reached. Its run fine for the past 9 years. Granted the SES was on and it always smelled rich i just figured it was lack of cats. Recently i decided i wanted a new project. Ive been researching cams for years and still didnt know exactly what to get. I called a local tuner who suggested BTR stg4, i called BTR who also recommended their stg4. I bought their cam kit, LS7 lifters, oil pump and LS2 timing chain/sprocket. I took the diablo off, installed everything (which went great). First start and a few heat cycles were awesome. Time to tune! I planed on using a well known highly recommended tuner in my region. A buddy told me to go to a local race shop here in town, which i did. Dyno tune day, he put his tune in and the afr had a jump in it around 4500rpm which seemed to move around each time he ran a pull. After 9 6500rpm pulls he was still unsure of the tune. Before it would start on its own after you had to give it throttle to start and idle. I left it with him a few days. He found that the O2 wernt reading correctly (my mistake for using the rear O2s when installing the headers). He replaced the O2s, Maf, Map and tps. Over $1200 later, we re-tuned and everything went well for the most part. 408whp

My question is with the new/final tune he had to set the "wheels in motion" idle @1600rpm (which looks completely stupid when pulling up to a red light/gas station/friends house).. He said the Map isnt responding so he had to base the tune off MAF only. Ive ran it the past few days and the 1600rpm idle seems to disappear from time to time. What would cause this?
Obviously im not very educated in tuning terms/procedures, any help/incite is greatly appreciated.

Once the PCM is tuned by a specific tuner can a second tuner re-tune?

ddnspider

iTrader: (26)

Sounds like you a)need to get the car mechanically sound and b)find a better tuner. I've tuned plenty of cars maf only and speed density only, some with large overlap and nothing ever had to idle at 1600.

RedTA02

Car is mechanically sound now, all new sensors, oil pump, lifters, cam, timing.... Installing cc trunions, ls6 pcv valley cover next week then looking at clutches and a 9" next. If i swap tuners, will the new tuner have any issues reading/re-tuning? I asked my current tuner for my tune and he said he doesnt give them out and that its locked?

ddnspider

iTrader: (26)

If he locked your computer he's a dick and a shady tuner. Tell him you want it flashed back to stock and unlocked, if he won't do that at least for you I'd run away. Typically only people who lock a tune are people who don't know what they're doing and don't want others see their mess, or some companies who think their stuff is gold and don't want you sharing.

mrvedit

Was it tuned on a dyno? If not, it probably isn't worth much anyway. Starting with an (unlocked) mail order tune might be better.

ddnspider

iTrader: (26)

I'm not sure I agree with that. Plenty of people tune their stuff exclusively on the street and the tunes are perfectly fine.

RedTA02

It was on the dyno both times.

Cv8

• guys i have a cv8 monaro 03
  i had a tune done and its stalling all the time please some info would be great
  it has
  228/234 cam with 113 lift
  Double valve springs
  try y extractors twin system 2.5
  Interceptor plug and play adjustable shift kit
  4000 g stally
  Maffless tune
  otr
  and a unichip
  (only got 348.9 wrhp)
  and doing only 14.3 qurter mile
  
  after the tune the stalling got worse
  and wile ******* around under the dash i found this unichip and spoken to some tuners all say that the unichip is fighting the tune but later on i found that one cat had been gutted so now in thinking that along with the chip the left bank had more compression then the right hence the stalling i now have to pay for another tune and have the unichip removed
  and she hit limiter at about 150/160 between 2nd and 3rd (real bad)
  
  now on to the next part
  in the last tune i was asked what i want from it eg fuel economy or power so i said
  some fuel economy
  dont want it to hunt
  
  but now for the next tune i want
  no fuel economy max power
  hunt off its *****
  and i want the 02 removed from the pcm
  any info would be great fellow ls lovers

ddnspider

iTrader: (26)

you need to get any chips/programmers off the car and get a real tune by someone who knows what they're doing. That cam should have no issues idling what so ever.

JakeFusion

iTrader: (7)

Why is this still a sticky? This has turned into a help me thread.

For this to be a sticky, it should provide useful information that is routinely searched for or provides a unique process/install that can be duplicated by many users.

So, to add something useful...

1) Lean out idle with bi-directional controls until it idles without the nannies then use that adjustment to tune MAF/VE table for idle
2) Disable LTFTs
3) Run the car in OL at idle (run it in PE mode of 0% throttle at idle cells 0-1200 and then set PE EQ at 1)
4) Disable cracker if you have a stalled auto
5) Get your Base Airflow within .5g/sec
6) Make sure your injector data doesn't suck
7) Add timing to get rid of "on throttle" surge or buck - some say take it away, but big or small cam, it's always responded better with more timing; but it does work because you get the car to lug with more load with less timing; more timing seems to work better for me - try it both ways
8) Make sure idle "off throttle" timing is within 2 degrees of the main spark table or else it'll buck
9) Run low spark timing in decel areas and run them rich to get rid of bucking
10) Increase follower multiplier with a large cam so it doesn't undershoot idle and increase decay so RPMs don't hang
11) Raise your cracker table to 10/9 mph enable/disable so adaptive spark kicks on sooner at parking lot speeds
12) Set your EOIT correctly so you can run it much leaner at idle - and then set your timing much lower than you think and gas smell and NOx is greatly reduced when you don't have cats

Etc.

ddnspider

iTrader: (26)

Words of wisdom right there

JakeFusion

iTrader: (7)

Yeah. Which is why it's good to use GM injectors, Ford injectors/Banish data, or Injector Dynamics where possible. And guess what, that covers from 28lbs injectors all the way up to 190lbs injectors and everything in between. So you shouldn't have to buy ebay specials and hope for the best.

Because everything else is a crap shoot.

ddnspider

iTrader: (26)

I always had good tunes with Banish data.

99 LS7

I have a 99 FRC with a LS7. The car runs well however I'm being told the car can only be tuned for drivability. Meaning it's capable of putting 550rwhp plus but anything over or close to 500 rwhp the ECU acts up. Loss of power flashes, the traction control comes on and it's just a freaking nightmare. Can anything be done to my ECU where it can keep up with the horsepower my car is capable of?