Need some help here, the car has some issuis idling.

It wont hold the Target Idle RPM vs Coolant temp for very long. The worst is when driving and you come to a stop sign, I have to fether the gas to keep it from stalling the idle go's too low.

Also when the idle drops that low I get a fog bank behind the car from it being way to rich, but it is not rich wile driving.

Car is a 1992 Z28 T-5 (730)
Cam is a comp NX276HR #12-415-8
276/288 224/236 @50 .502/.520lift with 1.5 (I have 1.6) 113LSA

I cant seem to figure out what to adjust to get the idle to stay up, been at this for awile now and getting frustrated

 

That's the same condition I had with my regulator being messed up.
Nice little hazy blue cloud from washing the oil off the cylinder walls at idle.
Was doing some funky stuff and "seemed" to be sticking at full psi or at least allot higher than the static pressure I initially set. Was sometimes good during driving but would return to BS the next day.
Still can't see how that is possible unless fuel was assisting the spring but not coming out of the adjustment. Anyway, the new regulator solved it for me.
If you've reset the TPS and IAC already, check the FP and see if thats the problem.

 

Shouldnt be the regulator its brand new

I think its the cam, from what I have read it seems do to the cam's overlap some of the intake charge appears to pass into the exhaust unburned, at low idle speeds. The oxygen sensor picks up the un burned oxygen and thinks the engine is running lean, then and adds fuel to compensate.

But everyone I have found in my searches seams to be MAF car's, not SD car's and nobody seems to mension an exact way to fix this

 

Check out RBobs writeup on the 727 fueling.
O2 switching constants may help you.

 

Didnt do anything really that I could tell so I put them back, heres new current chip seams to run the best sofar but still needs work, stallnig at an intersection is still an issue but it idles fine when just starting up and not moving the car.

 

Are you running a VSS? If not try opening you TB blades until you do not get a stall. This will work even if you do not run a VSS.

 

What bin did you use as a base for this?
Lots of differences from my compares on $8D files.

 

I have a good amount of overlap in my cam as well in my TBI V6 (222/230@.050, 112LSA), and I fought the idle for a long time. Either it would stall out or just rev uncontrollably. I eventually landed on raising the target idle a bit to 800, adding in a good amount of timing (currently idles at about 20*-22* advance), and limiting the IAC to 25 counts. At one point I ended up having to just unplug the IAC just so I could get the computer to leave well enough alone long enough that I could adjust the idle screw on the TBI and twist the distributor to figure out what the engine liked, then translated that back into the bin. Later on, I added a higher stall, and that helped settle down the idle issues a bit as well. The idle is rock steady now. I was out on some tuning runs just last night and got caught at a light for what seemed like forever, and it just sat there in drive and loped at 800 the whole time.

Teeleton

 

Thanx for the help guy's, I was gone all weekend but I'll be chk'n out what you told me and see if it works any.

JP86SS I bought my car with a Hypertech chip already in it so I used that as the startnig point and went from there.

 

Junk the Hyeprtech and use the closest stock bin to your application.

They do really stupid stuff with the timing and fans.

U will be much better off using the closest stock bin for your combo.

Idle is a very very very delicate balance of minimizing IAC events, both at idle and when returning to an idle like condition and also of finding the best AFR your car likes(tends to be richer, but i have seen lean improve on some combos) and what timing keeps your car happy.

Some might like the adder and subtracters at idle for the timing while other will fight it.

The other part is fully adjuting the IAC and TPS and TB almost everytime u make idle adjustments because they do work hand in hand.

later
Jeremy

 

OK so I unplug'd the IAC to see, defenetly a diference so some of my problem is there, but my Idle still drop's to about 500rpm at a stop sign it just doesnt stall now with the IAC unplug'd. I dont know why my idle is droppnig so low, I have it set at 1000rpm.

If I start the car and leave it, it seams to hold idle for a few minutes.

There are a couple VSS on in the chip, I got no clue what a VSS is so I have left them on for now.

 

VSS -Vehicle Speed Sensor. Part of the function is to 'keep alive' the idle. It knows when your car is moving and such. It is used to keep it from stalling when coming to a stop. Next is 500RPM may be a good stock setting but it will increase the idle steps. You need to open the blades to close to the desired idle to get the IAC or idle steps down. Note the car will run as high as the amount of air it can breathe.

 

Ok, so in fear of sounding like a complete moron here

What your saying is to turn off the VSS in the chip, disconnect the IAC and the manualy set the TB to the desired RPM then reconnect the IAC and and turn back on the VSS?

 

There are plenty of bins out there for you to try.
AXCN is a MT vette bin. Try it, just make sure that the N.O. fan flag is set the same as your FB bin.
There is also AXYC. But it's for a 305 and would require several setting to be swapped in from your bin. Some of which aren't defined in the public xdf's.
Note that lot's of people have ran the 305 mt bin w/o swapping all the settings. Just depends on how much accuracy you feel is needed.

 

VSS Pulses/Mile in the constants? My chip has 4006, would uping that increase my idle?

I downloaded 3 diferent AXCN bin's off moates and a couple others, gunna go through them but they all look as if they have been tampered with, one has 4024 pulses/mile.

 

VSS isn't the problem unless yours is faulty.
Vehicle speed (lack of) is one of the requirements to be met for the idle portion of the code to be put into effect.

What 69 Ghost is saying- open up your TB until you reach your desired idle with minimal IAC steps. Some shoot for 5-10 steps at warm idle.
Others go for 25-30 steps or so.
And reset you TPS & IAC.

 

Ok, so at a loss still.

With the IAC unpluged, Start the car it run's fine, idles at 1000-1100rpm, go for a spin around the block, still works great, second trip around the block and it will no longer hold the idle when coasting with the clutch in or sitting at a stop sign, doesnt stall but idle drops to about 500RPM and the smoke that comes out the back is nasty with unburned fuel. Hit the gas and hold it about 1000rpm, smoke clears up. Let off gas goes back to 500rpm or so. That is not what I have the Idle/Temp set at. Its set aprox 1000rpm.

The Idle Screw on my Holley 58mm TB is all the way out to its max now.

 

Don't know but sounds like you need to read up on some of the boards. Try this link first.
https://www.thirdgen.org/tpimod2

 

Actualy I just did the Idle IAC one before commnig back on here to do some more reading.

When I started engine with the IAC pulled, wouldnt idle to set an idle so I screwed it back out the the max it was at, still wouldnt idle

 

That bin appears to have been edited in a manor that makes it uneditable with public xdf's. For starters, your cyl number is at 20h. Not 00.
I also found some offset in the code area. Not much, just a little.
You need to start with a fresh bin and copy only those things you know are correct or needed from the HT chip. I wouldn't use any of it myself.

 

I edit it with Super_8dm2.ecu for definision file on TunerPro R/T, not sure what your using?

The cylinders should be set to 0 as per there instructions for a 8cyl car, which is what it show's to me.

Number of Cylinders
This is a value that tells the ECM the number of cylinders. The following values should be used:

# Cylinders Cal Value
3 = 96
4 = 128
6 = 192
8 = 0

I have tried 4 diferent base bin's sofar with the same effect Just bought a volt meter today to chk my TPS, might put the stock TB back on too to be sure its not the Holley, I got told some of them have issue's.

 

That second bin is f'd up.
Loaded with lots of 20h all over the place.
Might have been a bad burn or retrieval from the chip.
I don't see any way that bin would work.

The first one has all the stall saver settings above 500 rpm. Could be why you got bogus results when it went that low. lots of screwy looking changes in there.
Too many things that interact are radically changed IMO.
Get something that matches your setup (as close as possible) and then go from there.
Even stock settings (tweaked for inj etc) until you can get it running decent.
Then "maybe" go back and use some of the other bin settings.

Edit: if the screw is not long enough, put some tape or something on the tab to get more TB opening. Don't keep it that way but you will be able to get enough air to idle.
Then reset the TPS and IAC.

 

Yes, having an xdf that's about twice as long as Super_8dm2 is great for spotting differences. But that 20h for the cyl number stood out regardless.
Not sure how you saw 00......

 

I think it corupted when I zip'd it somehow because my copy apears to be fine :? What are you using for a xdf?

I am off to the Camaro Nationals this weekend so wot be donig anymore work on it untill next week, but thanx for the help sofar guy's
The Ontario Camaro Club :: The 2006 Nationals

Heres a new try at the current chip