Can you guys take a look at my mail order tune? The LT1 is a LE2 Heads/Cam, 30lb injector, long tubes, descreened maf and larger maf ends, 52mm tb, walbro fuel pump. This log is mostly at idle and driving around slow. The car has about 1000 miles on it right now. The first minute or 2 was in open loop. Towards the end I gun it for a few seconds in 1st gear and shift into 2nd.

I mainly want to make sure its safe to drive around until i get the tune touched up. It has a slight header leak.. tighten all the bolts but still leaking a bit somewhere. O2 sensors have 100k miles on them.


http://download.yousendit.com/E625BFA87DB7633E

 

Honestly you should fix the leak and throw a new set of O2s on the car before datalogging, since that can have an effect what the PCM is "seeing".
Who did the tune for you anyway?

 

Still offering to show your tune? I'd like to compare with my tune. Very similar-sounding engine combo here...

 

Yeah I'll actually re log it and send it... put it back up in few days.

I discovered that my new walbro's check valve is open.... and stays open... I believe it's effecting the tune... and giving the car slight lag when I give just a little bit of throttle.

 

Unfortunately 02's only do what they do, and that's detect what they think is air/fuel ratio. Given you have an exhaust leak can only assume that's messing up the effective "calibration" of the 02 sensor as the PCM see's it.

PCM will try to do whatever it can to hit 14.7 in closed loop mode, but that doesnt say anything really, could be 5:1 or 18:1 AFR in reality.

Firstly if there's NO KNOCK then drive, secondly drive as long as it feels crisp with fast clean throttle response and not overheating (overheating = severly retarted timing). If it BUCKS AND KICKS or surges at tip in or accel/WOT then that's LEAN or ignition problem, and if that is only at tip in or similar then drive. If it is sluggish (like random missfire under load) or blows black smoke (even slight) then that's extremly rich and can be worse than slightly lean, due to gas to oil contamination and ring wash out (which I dont know really exsists).

If none of the above, no knock at WOT EVER, and it just drives great then I wouldnt worry about anything, tune at your own convienience. You might gain a few HP from a tune but dont expect wonders.

You can use the 02 value to see if it's enriching or leaning fuel when you "give just a bit of throttle", on a perfect tune it should go a little rich during the transition then recover, if it pegs lean (0-75) then yea it's lean tip in stumble. Enjoy.


(replies like this tend to attract extremely techie people (or person) who like to debate how an 02 sensor actually works which will get you nowhere real fast... thinking by saying this we wont get that type of response)...

 

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(replies like this tend to attract extremely techie people (or person) who like to debate how an 02 sensor actually works which will get you nowhere real fast... thinking by saying this we wont get that type of response)...[/QUOTE]

Well lets hope so...

I have since fixed the exhaust leak that I had.. The car only bucks and surges alittle bit at very low throttle. Anytime I accelerate its smooth. I have false knock since installing the roller rockers years ago.... I've always been able to hear the roller rockers.. had them in a couple different engines and tried adjusting the lash but they remain noisy.

I have about 4000 miles on the engine... Getting ready to do the 2nd oil change. Oil pressure and temp is good... And power is up there.. There is a noticeable difference from my car and my friends dynoed 360rwhp firebird. So I know mine is well up there in power... No odd color smoke coming from the exhaust either.

I'll post up the log after the weekend when I get back from the beach