94m6Z28

car will not hold and idle scince its been tuned. car starts and will idle up to around 1800rpms, about 5 seconds, then slolwey drop down to set desired idle of about 800-900rpms, takes about 10 secons in total, *desired idle in computer is 800rpms* then it will quickley rev it self up to 1900-2000rpms and sit there. and idle ruff witch it dosent do untill it idles back up *start up and idle down are all smooth* if you drive the car for a bit and then come to a stop it does the same thing, idles down smooth and fine to set idle for about 3 seconds then will hop up to 2000rpms and idle ruff.

i have checked for vac leaks and there is none, the idle air count is at 32 counts once it has idled back up so its right in spec, TPS is .66. i have deleted AIR and EGR. the computer still puts in a request for AIR. ive run this by the place that tuned it and so far nothing really.

any help or ideas would be awasome

1994 camaro lt1
OFI Kit
racetronixs 44's
PCM4less tune
deleted emmisions

94m6Z28

any one?

94m6Z28

come on guys, some one has to have some clue

macca_779

Mate what do you want to know. Obviously the place that did the tune stuffed up so get them to fix it. It could be lots of things. Desired Air, Follower, Decay. Not much we can do about it without a copy of the tune and some logs.

94m6Z28

the place that tuned it says there is nothing wrong.. what valuves would be needed to help then?

they wont send me a copy of the tune

moehorsepower

iTrader: (3)

Agreed, if this started AFTER the tune, and nothing else was touched then obviously it is in the tune, Instead of you racking you brains trying to figure it out I would make them fix the problem...

9000th01ss

iTrader: (10)

What vehicle is this? How did you go about tuning it?
If it's a '94 it has a chip that gets flashed and burned (I have the stuff, I'm not talking out of my ***)
And how do you drive home from the tuner and not notice this?

moehorsepower

iTrader: (3)

[QUOTE=9000th01ss;9819543]
If it's a '94 it has a chip that gets flashed and burned (I have the stuff, I'm not talking out of my ***)


well Not to flame you, but 94's are not chips, they are E-prom chips that get flashed just like the 95's on up...

9000th01ss

iTrader: (10)

Ok it's '93 and down I was thinking of. I've been doing trucks and they're '95 down.

hellbents10

iTrader: (10)

At that voltage you should not be close to 1% TPS but if the TPS is getting wacky you could have that problem. Sounds like maybe your IAC could be going crazy too.

ZDOG

iTrader: (13)

tuners are never wrong....but its always there fault.
look over some of the basic stuff. use amultimeter and check any sensor that has bearing on the issue.

does it do it on cold idle open loop?

Eurospec2

iTrader: (2)

Kinda makes you wonder why they don't want you to see it

macca_779

Well they are obviously talking **** if it was fine before you took the car to them.. Id say they don't want to send you the tune, because its crap.

94m6Z28

i have gone threw and checked sensors, even unplugs them to see if it changes any thing. it dose not effect any thing at all besides the SES light

it was a mail order tune. i know, bad idea...but i thought it would be better to have a safe tune inplace of no tune untill i found a local place to do it. its going into a shop friday.. ivere done the intake manifold gaskets twice now, along with all the EGR block off stuff

could it be "hunting" for the idle even if there is a pre set idle in the computer?

it has been with out power for a good 4 months.. only had the car together and running around july 1's

macca_779

Yes it can hunt regardless of what desired idle is. Stop looking for mechanical issues mate.. Its in the tune and nothing more. If your going to a shop this week I wouldn't even worry about it because they will no doubt fix it for you. Ask them to show you the idle trims. I'll bet good money they are way out.

94m6Z28

ive spent money chaseing the computer befor haha

what changes in the computer when you go voer 2500rpms?

as the car is now, any thing udner 2500rpms the tach needle jumps oround a bit, like an old car with open headers. as soon as i go up to 3000rpms. just lighting pressing on the gass, like you would when taking off from a stop in heavy traffic., the needled will jiggle around up to 3 grand. hit the 3000 mark on the tack, the needle will FALL right to 2500rpms and it runs perfect..just like it did from the factory...do tables change at this rpm?

macca_779

All the IAC tables do different things depending on lots of different conditions. TP%, RPM, SPEED to name a few have an influence on Idle control. And even then it depends on how the tune is set up. 2500rpm is not a fixed value. It depends on how the tuner sets up the tables. Since you can't get us the tune to look at there really is nothing we can do for you except tell you to get back to your bum of a tuner and tell him to fix the bloody thing.. If he can't, demand a refund and move elsewhere. Or better yet buy EFI LIVE and tune it yourself.

Frost

iTrader: (45)

for a 94 LT1??

moehorsepower

iTrader: (3)

OK, Now you throw in another issue, Tach jumping around. The opti at times will also do this, I have had this before but at idle my tach was jumping around, finally the opti went out, installed a new one, tach was steady as she goes...Opti going out just after a tune? coincidence? Hmmmm

94m6Z28

its got a brand new opti, even lock tighted the screws and the hole set up has maybe 110miles on it..MAYBE. repalced the idle air con. valve, old one was jamed and not moving at all..dident change any thing at all but hay. its going into the shop 2morrow morning, any thing i should have them get to help with the online diag?

any valves of sorts?

and i mentiond the tack jump then steadying out becuse i thought it was funny that when the tach settled out and read dead on the car ran perfect, its just in that one rage where the needle is hopping around. wondering if by any chance it could be related or just a random thing