Rough idle no matter what ! - Tuning Forum

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Rough idle no matter what !
Friday, September 25, 2009 8:09 PM

I have a 2.2 pontiac sunfire i just bought and the car and motor was built and a turbo added with an intercooler.
I had the ecu custom tuned flahed for 32lb injectors and it runs rough. and hesitates until i slowly depress the gas pedall to 3000rpm then after that it is smooth all the way to 6000rpm in neutral. It runs like crap according to the previous owner the car ran fine with the stock injectors.I checked all the ecu grounds are good.
.
So i replaced the computer with another one still the same and did a crank relearn. I replaced the cranks sensor the map sensor the coil packs-the ignition module the fuel pump and the fuel pressure is good, and new plugs.
It runs like it has a bad missfire you can hear it through the exhaust .Compression is good. 135psi all 4 cylinders. I installed the stock injectors and the stock computer tune it wont even start. with that So i changed the injector value from 017760 to 09442 and it starts and hesistates if you quickly hit the throttle.But if you lightly depress the throttle it will rev smoothly all the way to 6000rpm. but it still runs like it has a bad missfire.The map sensor is stock and should run at idle until boost kicks in.
My question is why would it not run with the stock tune and injectors?Afr is 16.00 at idle the slowly richens like normal cars does. I looked at teh timing marks on the gears up top and they were dead on.

ANY HELP WOULD BE APPRCIATED . Thanks.

Re: Rough idle no matter what !
Friday, September 25, 2009 8:27 PM
[ion] C2 Online
Check for vacuum leaks.


2001 Olds Alero (LD9)
650 whp / 543 ft-lb
@turboalero
Re: Rough idle no matter what !
Saturday, September 26, 2009 12:18 PM
Sounds to me like there's too much fuel. Either it's not tuned right, or you just can't turn down the injectors far enough.





i find it amusing that SHOoff has nothing better to do but follow me around & be an unhelpful dick in even cross-forum. - Jon Mick
Re: Rough idle no matter what !
Saturday, September 26, 2009 1:06 PM
SHOoff wrote:Sounds to me like there's too much fuel. Either it's not tuned right, or you just can't turn down the injectors far enough.



17 Iinches vaccum ahd the intake off no leaks found.Sprayed 2+2 cleaner around the engine and intake no leaks. STOCK injectors and the car wont run with the stock tune and LEAN OUT the injector scale and it runs. 16afr at idle.Add more fuel and it runs worse.Everything is stock but the turbo.
Re: Rough idle no matter what !
Saturday, September 26, 2009 6:55 PM
whats your fuel pressure at? How do the plugs look? Lets see a cpy of the tune...





P&P Tuning
420.5whp / 359.8wtq

Re: Rough idle no matter what !
Saturday, September 26, 2009 8:46 PM
What are you using to tune?
Hp Tuners?
Re: Rough idle no matter what !
Saturday, September 26, 2009 9:18 PM
I did a tune for 32lb injectors and it was pig rich originaly when i had the 32lb injectors for 8 psi. I want to put 14psi.

I use HP tuners.

I will post a copy of the tune.

Thanks.
Re: Rough idle no matter what !
Monday, September 28, 2009 4:07 PM
Here is what i found out today,


I found out the previous owner that rebulit that motor,
bought the motor from a junkyard had it rebuilt with forged pistons and he is not sure what year it was.The 2.2 ecotech engine might be a for a vin 4 because the crank is different for a vin F which is the car a 2003 pontiac sunfire.
So iam researching to see what is the difference? Because the ckp sensor picks up the siignal from there.Which would explain why it runs like it does and not firing on all cylinders.That is my next step.
Re: Rough idle no matter what !
Monday, September 28, 2009 4:16 PM
Where are the casting numbers on this block so i can identify if it is a VIN F or 4 ?
Re: Rough idle no matter what !
Monday, September 28, 2009 5:20 PM
Paul Farago wrote:Where are the casting numbers on this block so i can identify if it is a VIN F or 4 ?
VIN 4 is not an ECO, its an OHV... Non interchangable.....



P&P Tuning
420.5whp / 359.8wtq

Re: Rough idle no matter what !
Monday, September 28, 2009 7:07 PM
Is it possible that the engine has a different crank? than 03 pontiac sunfire ? The previous owner said he thinks it was an 03 or and 02 cavalier engine not sure what.
Could be a different ecotech with different crank?

Re: Rough idle no matter what !
Monday, September 28, 2009 7:51 PM
If I'm not mistaken

2002-2005 are all l61.
All l61 have a 7+1 Crank trigger.
I wouldn't think this is your problem.
Though you can get the pin out for the ecm harness, and locate the Vr (crank trigger) sensor pins.
Pull the harness off the ecm and use an osiliscope to verify that you are getting a 6+1 (6 evenly spaced waves +1 irregular(which coincides with 10 btdc)).

Though I don't think this is your problem.

Sounds like you need to tune it better.

I would bring it to a shop that tunes HP Tuners and have them teach you.
You'll get your car tuned and learn a bit I suppose....

I would suspect that your injector constants are not set properly.
You gotta keep in mind as well
injectors are rated for x/lbs @ a certain psi. Raise or lower the psi and you have a different x/lbs

Sorry I can't be of more help.
I'm not to familiar with Hp tuners...
Re: Rough idle no matter what !
Tuesday, September 29, 2009 3:31 PM
I understand what you are saying but i put the stock injectors and tune and the car wont even start !
It starts only when i make the factory injectcor even smaller!
Re: Rough idle no matter what !
Wednesday, September 30, 2009 10:50 AM
You said the fuel pressure is good - where are you measuring it and what is the value in PSI?



Re: Rough idle no matter what !
Wednesday, September 30, 2009 11:00 AM
NeedTurbo wrote:If I'm not mistaken

2002-2005 are all L61s...



2002 had eco, ld9 and ln2 motors from 03-05 it was all eco.






Re: Rough idle no matter what !
Wednesday, September 30, 2009 2:29 PM
Quote:

All l61 have a 7+1 Crank trigger.
I wouldn't think this is your problem.
Though you can get the pin out for the ecm harness, and locate the Vr (crank trigger) sensor pins.
Pull the harness off the ecm and use an osiliscope to verify that you are getting a 6+1 (6 evenly spaced waves +1 irregular(which coincides with 10 btdc)).



Haha I said 7+1 and 6+1 in the same paragraph....
6+1 is correct...

When you say stock tune, are you referring to the factory provided n/a tune? ( I hope not....)
Or the Eco reflash?
OR the "stock" tune that was given to you with the car?

If you do infact have a l61,
and your that reluctant to goto a dyno shop.
I would maybe recommend the eco reflash?



Also,
from your posts I think we're all assuming that your using a wideband AND a narrowband (hooked to your ecm)
could you clairify?

Where did you get your injectors from?
Test the resistance across one (from both sets) of your injectors....
If one set is low imp and one is high, this may have caused damage to your ecm(s)....

If for example the 32/lb injectors you bought were low imp,
and if you tried that with your "Ecm#1".
then decided to try the new (stock) "ecm#2" with the same injectors
you could have damaged the injector drivers.
Maybe causing your problems?

Lol I donno...
What a rant..
Sry dude..
Re: Rough idle no matter what !
Wednesday, September 30, 2009 3:54 PM
Stock tune meanning i bought the same ecu form the junk yard matching numbers.I read the ecu from the junk yard and changed the vin on it. 03 sunfire 2.2
Then i downloaded form the hp TUNERS repository another stock tune tried that also. NO luck.


I bought the injectors and rails off ebay for a stock 02 to 05 cavalier or sunfire were is how they were listed.
Readings are from a wideband that is hooked on the car.
The previous injectors were 32lb ACCELS yellow top.
The ecm i had was also send to the part store and had it reflashed and it checked good..
I tried both ecms ! With both injectors stock and the 32's ACCELS

Going to the dyno is not going to cure the hesitation and rough idle.

Iam going to check the ressistance of the ebay injectors i bought tommorow.

iTS NOT OVER TILL THE FAT LADY SINGS. HEHEHEHEHHEHEE

Iam going to find what the problem is.It s a car not the space shuttle.

All help is are appreciated.
Re: Rough idle no matter what !
Tuesday, October 06, 2009 3:46 PM
Today i found and repaired the problem!

The previous owner had the engine rebuilt with forged internals.When the exhaust cam was installed it was lined up on the intake tooth not the exhaust tooth!
I alighned the engine timing marks and installed the 32lb injectors and the tune back and runs like a champ!

The strange thing is that it did not bend any valves!
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