Lee@woodworks.ca

My 69 Camaro with the LS1 / T56 conversion ( www.lees69camaro.com ) runs poor from idle to about 1500 RPM. It runs great other than that. When cold, its worse. Sometimes when cold it wants to stall, the engine hunts from 500 to 1500 rpm until it either stalls or settles around 900. When it's warm, it's very tempermental to drive at low RPM. If cruising in a higher gear, and 1500 rpm, the car wants to serge or jurk a little. I always have to downshift, raising the RPM to keep it driving smooth.
My tech guy has been trying to adjust the values and by adding more fuel, but I think one of my problems is the previous owner of the donor corvette (before he wrapped it around a pole) added a cam and weI have no idea of the cam specs. I didn't want to remove the computer and send it out for someone else to guess. Can anyone offer suggestions that might help this thing run better at low RPM?
It's a 1998 Corvette LS1, factory 6 speed. I am running an after market Granatelli MAF for the correct application and stock air intake temp sensor. Here in Canada we have what's called a mandatory aircare (smog) test and it fails misserably but only at idle with Hydro Carbons off the scale.
Any help is great appreciated.
Lee

Jones'n

First thing I'd say is ditch the aftermarket MAF. I've never heard any of them working well unless the person tuning it REALLY knows how to dial it in.

Frost

iTrader: (45)

high hydrocarbons and swinging idle suggest overfueling down low already, tell your buddy not to fatten it up on the bottom.

Frost

iTrader: (45)

what are you tuning with; could you post a file?

BLK02WS6

iTrader: (2)

lean out the idle using the VE table, increase the idle timing, and increase the running air flow in the idle tables... how much on each depends on the cam... since you don't know, make small changes to each (some starting points would be lean out 10%, 24 degrees timing at idle, add 1.4 to all running airflow values), and it will let you know when its happy. Hope that helps.

Lee@woodworks.ca

Thanks you guys.
I'll try your suggestions.

Doc

iTrader: (9)

Nice looking project. It looks like you have spent a lot of time and care assembling it. Finish off the project with a wideband 02 sensor. You need to accurately calibrate your fuel. Don't guess.