Help with Idle Tuning

[Cap'n B]

I changed from the stock intake manifold & TB to a F A S T LSXrt manifold and a 102 mm TB, I also changed Cams, from 226/226 .585/.585 112 LSA to 226/230 .598/.600 113+2 LSA. I also had the heads shaved .050.The engine is a 5.3 with stock bottom end I'm having trouble with the idle and I've never tuned for idling before. What do I need to scan to find out where my problem is. I'm not sure what PID's to set up in the primary table. Please keep it simple. The Idle in gear is not bad but in neutral it starts up at about 2000 then slows down for a little while, around 900 then it speeds back up then slows down then stops. If I touch the accelerator it speeds way up.

[PitchblackC3]

This is on the 99?
DBC?

[Cap'n B]

yes it is

[GPGTP]

Have you tuned your maf and ve table yet? That's the first step.

[Cap'n B]

VE table is off,when Maf is disabled but looks good when maf is enabled. within 4% with MAF enabled

[GPGTP]

that's because when the maf's enabled it's using the maf. You need to disable it and THEN tune the VE table.

[Cap'n B]

ok I understand I need to disable it to tune VE table ,but since the VE table is within 4% on the trims with it enabled is it ok to assume the MAF is tuned?

[Cap'n B]

NO thoughts or opinions?

I'm working on the VE table

[Higgs Boson]

No. You can't tell what the VE is unless the MAF is disabled and you can't tell what the MAF is unless VE is disabled.

[Cap'n B]

OK thanks, i was thinking that if the ve was good when the MAF is enabled that the MAF was tuned. I still got a lot to learn, but i'm reading what I can and trying to understand it all.

[mrfister77]

What do you think of that intake and tb?

[Cap'n B]

What do you think of that intake and tb?

It pulls hard with the FAST Intake, the throttlebody right now not sure until I can get it to idle. SO far it's showing a big improvement over stock.

I haven't been able to work on VE table any more lately, I'm getting my shrimp boat ready and we just came back from Camaro5 Fest in AZ.

[Cap'n B]

I believe the VE table is good, here is my last scan log and tune, MAF is still disabled

[Ben Charles]

To be honest I would make sure the IAC counts are in order (around 60) then I would do the Russ K Idle config. Your basically just running a cam setup with a little better induction. After these two things then I would work on VE then on the MAF. For starters on the VE table lower the everything from 1200 down by .60 from the factory VE table, somewhere in the midrange the VE table will match factory and then start to be higher.

BTW are you starting out with a 5.3 file or LS1 file?

[Cap'n B]

Before I changed the intake manifold and Cam it was idling good,I already had an aftermarket cam tune. now it won't idle, I was told to tune in VE table first. I do have the original LM7 tune with original '99 ECM.

1) What is the correct PID to insert to scan IAC count

2) I'm not sure how to do the multiply by % thing never did it.

3) Can I find TPS voltage in HP Tuner or do I use a voltmeter? If using a voltmeter, I just put the red point on 1 wire and the black on the other wire?

[Cap'n B]

Anybody

[Ben Charles]

Find the Russk Idle config on here ( several post about it) it has a histogram with all the pids you will need including IAC, TPS, etc.

Use a voltmeter on the TPS to see what the voltage is, I am an LTX engine so its probably different, but ground goes to black and power goes to blue to see voltage.

[Cap'n B]

Thanx Ben

[detroit]

you need to model the airflow (the VE) before you do anything and looking at your second question, I dont think you have changed the VE table any, bc it is necessary to use that function to fix the error in the table.

I would do the VE before I run any of the RussK stuff.

Injector data>good ve table>MAF (Optional)>fine tuning idle, hot starts...

[copley87blazer]

Ve first, if you can get it to idle at all, or it stumbles at idle raise the idlle rpm 100 or so