Does not idle until stopped, hanging rpm's

[sfc rick]

I never used HP Tuners other than to adjust idle rpms. I never adjusted anything in tables or base airflow etc,etc.

I looked at sticky's but I'm too uneducated to understand all the lingo about LTIT's or RFF's and other things.

My car ran perfectly up till yesterday. I sent my heads for a 5 angle valve job and a little mill to clean up the heads.

Here's the problem, it would hang in high rpms(1200-1500) when I pushed the clutch in and pull up to a light/stop sign, then once completely stopped the rpms would drop to idle(875). Once completely stopped it would surge a little up and down to like (875-1100). BUT once the car rolled away from stop the rpms go back to 1500-2000 and hang there until completely stopped again.

I have checked for air leaks and none were found. It's a 98 C5 and someone told me to check my IAC and clean it. I thought that solenoid on the Throttle blade wasn't a step motor but actually a electronic throttle?

Never had a problem before what to do? Any suggestions?

Here's the tune,

[sfc rick]

Update since no one here volunteered anything. I ran a scan while it was running and it showed a LTFT of 3.1 on B1 and a 7.0 on B2. The guys at Texas Speed suggested I check my O2 sensors cause one side was way out of wack. I noticed when I reloaded the tune this morning it ran perfect once more but when I started it back a couple of hours later it reverted to surging and hanging rpms again. Texas Spedd said that may indicate it's reading the fuel trims and trying to get it adjusted, but fouled O2's may be giving it problems.

Before I had the valve job done, my engine did burn oil and puff out blue smoke on start up and eventually started blowing a little just going down the road, this lasted about 2 months.

So I guess it's possible it fouled them out.

[99LS1SS]

What are your mods? Do you have a cam?

[99LS1SS]

How much did you get your heads milled?

There are a lot of tables that have been altered in your tune. If you didn't do them then you might be better off starting from scratch...depending on your mods.

[sfc rick]

What are your mods? Do you have a cam?

LS6 manifold, Vararam, Lg Streets Longtube headers, Texas Speed 228R-112 cam.

It was tuned using the mods, and then I had my stock 806 heads w/valve job installed. They weren't milled that much, just enough to clean up the surface.

[99LS1SS]

PM me your email and I'll see if I can't get your idle leveled out.

[sfc rick]

pm sent w/email address

[99LS1SS]

You have an email. I've changed a few tables for you. Let me know if that helps.

[sfc rick]

OK, I'll get back to you shortly

[sfc rick]

Here's how this was solved.........I messed up.....plain and simple. After installing the heads and having the problem I called Texas Speed and Performance and they promptly told me to check for an air leak. I said Duhhhhhh! like I knew there was no air leak, even checked again, then took off the manifold and retorqued everything....no leaks!

Anyway...I was bugging Jason and Jake at the TSP shop for help saying it HAD TO BE in the tune!

Later, last night in the shop with the hood up and FRC's off the engine, I cranked it up as usual and looked for any sign of a vacuum leak, no sign nada, nothing. Then out of the blue, the danged engine started whistling at me.....NO KIDDING! It was just like someone was whistling at you! The whistle came from the oil catch can....where a hose was loose! WHISTLING at me! Talk about feeling stupid!

I called TSP up and told them what really was wrong and I was at fault!

[99LS1SS]

Very good to hear Rick.