rpmatredline

I have a BBK/Edelbrock 52mm tb...I don't know what is the the better option, My car idles a little rough for the first 2 minutes then smooths out & seems to be fine once warmed up. I currently adjusted the throttle blades and the TPS. I don't have any tuning tools to know what my BLM's are but it seems to run ok, Just a rough idle for a couple of minutes. I've been wondering though with that method could everything still be as accurate with the BLM's as Drilling the hole in the passage of throttle body, Or should I do the 11/64 hole thing?

Luke1996ta

iTrader: (3)

Any codes o2 sensor?

rpmatredline

No, no 02 codes

F0x Slaughter

When the car is warming up its in open loop. The o2s arent reading so it pulls from the a few different tables to get the AFR.

Did you even port your intake manifold? Stock is 48mm.

rpmatredline

Yeah LE ported intake to 58mm , but stock intake bores are 52mm , The stock throttlebody is 48mm.

96capricemgr

iTrader: (1)

The IAC is probably maxxed out at cold start causing the rough idle, as the engine warms up and needs less air to idle is smooths out.

Adjusting the throttle blades to give it more idle air defeats the IAC distribution circuit IF it actually works on your TB some earlier ones were seals later ones are not.

If going 52mm I would strongly encourage people to use rebored stockers to avoid these issues, and when going 58mm educate yourself on how to deal with them.

Far as the intake openings most seem to be 52mm but a few folks have measure 54mm so there may have been some variation but certainly not 48mm as one guy suggested.

FAD2BLK93

Is IAC working properly? How about coolant temp sensor? Try and log whats going on in the data stream.

rpmatredline

yeah I guess i'll have to get some programs or find someone that knows what is going on, since i have had the car 16 yrs and plan on keepin it, I might as well learn to tune it a little.