blubird

iTrader: (8)

When coasting in neatral clutch pedal out rpm holds rock steady. When I depress the clutch idle surges badly until the car slows enough to enter ss ideal routines(10mph). Any ideas what causes this and how to fix it?

nikon1999

iTrader: (22)

i believe that would be your throttle cracker table more than likely

Steel Chicken

iTrader: (3)

make sure your base airflow table is good first. thats what it was when I had that issue.

blubird

iTrader: (8)

It's the throttle cracker airflow that's keeping the idle steady when I'm coasting with shifter in neutral and clutch pedal out. If I adjust my base airflow will that also not offset the throttle cracker airflow? I think I might just need to see what my IAC counts are doing immediately after I push in the clutch.

Thanks for the input keep the ideas coming if you got em.

Steel Chicken

iTrader: (3)

it *might* be the cracker, but it might not. I had the same problem after a cam install. I messed with the cracker table and bunch of other stuff and it never really fixed it. tuning is like building a pyramid, you have to have the foundations right first before polishing the top levels.

go here http://redhardsupra.blogspot.com/ and read the RAF Idle tuning entries.

until you know your RAF is good, theres a good chance your wasting your time.

blubird

iTrader: (8)

Thanks for the link! i'll try messing with it this weekend. Most everything about my car's tune seems to be working well, but I have a couple of things I keep chasing my tail on. Looks like I'll have to start over on a couple of things. Thanks again for the input.

ninobrn99

iTrader: (8)

im having a similar issue..i think. at idle, when im coming to stop and let the clutch out and put it in neutral while braking, the cars rpms dip to about 2-300 rpm and then climb back up again. Its getting old and frustrating. My RAF was tuned, but it started happening after I dyno'd. It also happens when the maf is plugged in, but after it warms up it doesnt do it anymore until i shut the car off and restart it. Its pretty confusing. I havent done too much trouble shooting, but once I get my HPT cable back, im going to install my WB and see what i can figure out. Im taking it as close to stock as possible, but I think maybe my ls6 intake manifoldis cracked...maybe..what else could cause the idle issues? Ive checked for leaks, none, ive checked to see if the manifold came loose, it didnt. I retorqued the bolts. Who knows. Good luck.

blubird

iTrader: (8)

I finally got everything worked out. I started over with my idle tuning. I changed the idle speed by using the vcm controls in hptuners. I adjusted the idle speed up and down until I got minimum oscillations in sprak control. I then disabled the idle spark control and adjusted the base spark advance until I got the smallest oscillation in idle speed. As it turns out the higher the timing the more the idle would surge. My final base timing was 12 deg. and idle rpm was 1050.

I did a few cold startups and adjusted my base airflow and now my STITs stay between 0-0.3 g/sec. Once that was complete I had to almost zero out my throttle cracker table to keep the idle speed from jumping up during decel in neutral.

All surging and stalling in gone and the idle is extremely tame. I have a 236/240 111lsa cam that you would think is no bigger than a 220ish cam.

Thanks all for the advice. It got me fired up about fixing my tune.