purevilss

I hear about drilling the throttle-body, but was looking for a way with LS1 Edit. Is there a way. The problem that I am having is, I raised my idle up to 1000RPM's minimum yet when I start the car it just bounces from like 200-800 RPM's and dies. This happens no matter if I am in gear, park, or neutral. If I don't keep my foot on the pedal, it surges heavily and dies.

Cal

iTrader: (1)

Ok with a 227/224 and a 1000 rpm, there is no way you can get around drilling the TB plate, especially if you want it to actually maintain that idle speed with the A/C on. Now that I've said that, watch someone say you still don't need to to drill the TB. But if you watch what's going on with EFILive, you will see the PCM jacking the IACs up until they max out, yet it still will not hold that idle speed. Just drill it out to .250 inch, bump up idle timing 5 degrees, and scale your VE down to about 60% 1200 rpm and below and you'll be OK. It will hunt for the first few seconds, but shouldn't die. You can fine tune the VE for the three idle speeds 1200 and below to get it even better.

Ed Blown Vert

iTrader: (2)

Well Cal sure I will.

I didn't have drill my TB, or change anything in EDIT except to raise my idle to 775.

All I did was turn the idle screw a bit to get my IAC's to 50 and I still was able to keep my TPS @ 0%

purevilss

Which screw is the idle screw, on the t-body? I will give it a shot first, then drill if it don't work. I think that I will adjust the VE and timing anyways though. Thanks for the advice and ideas.

Cal

iTrader: (1)

Turning the idle stop screw is not the best way to get more air into the engine at idle. There are two problems with adjusting the screw: 1)The screw is VERY sensitive, 2)This changes the TP sensor at the same time, meaning the PCM will think you have your foot on the gas so it will never think the engine is supposed to be idling. These are the reasons most people wind up drilling the TB plate sooner or later after a cam install.

purevilss

Thanks Cal. Do you mean a .250" drill bit or one .025 larger than the hole already is?

purevilss

Cal, do I use the VE or crank VE tab? Also do I scale through all the MAP at those RPM's?

Ed Blown Vert

iTrader: (2)

I never had good luck with the VE tables. You might look at the IAC Park and Idle tables.
Oh and its the VE table not the Crank VE.

NoGo

iTrader: (2)

I don't want to step on anybody's toes here, but you will be able to get it to idle without drilling your TB. I actually prefer not to drill the TB. We tune 240+ cams without drilling the TB.

Here are some things you can try.

Idle Limiters --> Idle Speed: 950
Idle Limiters --> IAC Park Position: Raise all points from 40C and up to 21
Idle Limiters --> Idle Air In Gear: All points 60C and up to 8.6
Fuel --> Main VE Table: Multiply column 400 rpm by 60. Multiply column 800 by 80. Multiply column 1200 by 90.
Ignition --> High Octane Table: Add 2 deg to all points 400 to 1000 RPM, .08 to .32 g/sec

Once done with this program, start the car and check for surging. If the car surges, unplug the IAC and see if the surging stops. If the surging stops follow below.

Idle Limiters --> Idle Air in Gear --> All points above 60C to 9.2

Take the car for a drive and check your idle. If the car goes on cruise control reduce the Idle Air in Gear Table .2 (further if necessary). If the idle holds at 2000 RPM for extended periods of time reduce the P/N Airflow Decay table for all points above 10 MPH by 5% (multiply by 95) until this stops. Be vary careful on this table.

If car keeps surging with the IAC unplugged two more things to try.
Multiply Main VE table by another 95% (total reduction of 85%). Repeat until the surging goes away, or until the car begins to hesitate when you take off.
High Octane Ignition Table. Reduce timing for all points 400 to 1000 RPM, .08 to .32 g/sec by 2. Repeat, but don't reduce it any more than 6 degrees.


If your car still doesn't idle after this, then you have other problems, and should start looking elsewhere.


Good Luck