Idle issue on cammed LS1
11-06-2011, 11:01 AM
#1
On The Tree
Thread Starter
iTrader: (2)
Join Date: Jul 2005
Location: Cleveland, OH
Posts: 129
Likes: 0
Received 0 Likes
on
0 Posts
Idle issue on cammed LS1 I've been tweaking around trying to get this car to behave, without much success. I'll post a tune and log to follow this, any guidance would be appreciated!
Car is a 98 Z28, stock 346 bottom w/ TFS heads, Fast 92/92mm tb, Vengeance VRX5 cam, and all the bolt-ons.
Seems no matter what I do with VE's, spark, and idle settings I can't get it to behave well enough. As it is now, it'll get into a cycle where it surges pretty wildly, to the point of stalling if I don't give it a little throttle to help it out.
On the log that will be below in a moment, I drove around and bit and ended as I pulled in the driveway. Pulled in normally, came to a stop, and let it sit and idle. It was idling well enough. Gave it a little throttle (up to a little over 2000 RPM), then let off. It started surging around, finally stalling.
Ideas? Help please!?!?
Car is a 98 Z28, stock 346 bottom w/ TFS heads, Fast 92/92mm tb, Vengeance VRX5 cam, and all the bolt-ons.
Seems no matter what I do with VE's, spark, and idle settings I can't get it to behave well enough. As it is now, it'll get into a cycle where it surges pretty wildly, to the point of stalling if I don't give it a little throttle to help it out.
On the log that will be below in a moment, I drove around and bit and ended as I pulled in the driveway. Pulled in normally, came to a stop, and let it sit and idle. It was idling well enough. Gave it a little throttle (up to a little over 2000 RPM), then let off. It started surging around, finally stalling.
Ideas? Help please!?!?
11-06-2011, 12:32 PM
#4
On The Tree
Thread Starter
iTrader: (2)
Join Date: Jul 2005
Location: Cleveland, OH
Posts: 129
Likes: 0
Received 0 Likes
on
0 Posts
Still playing.... idles decently if I use the scanner to force OL.
Disabled idle proportional in the fuel > OL/CL tab, issue still persists.
I notice at idle the STFT's just creep higher and higher... ???
Disabled idle proportional in the fuel > OL/CL tab, issue still persists.
I notice at idle the STFT's just creep higher and higher... ???
Trending Topics
11-07-2011, 01:39 PM
#8
Teching In
Join Date: Apr 2011
Posts: 12
Likes: 0
Received 0 Likes
on
0 Posts
I'd be willing to bet its a combination of bad injector data, the fuel trims are pretty far off, and the VE map looks like the Colorado Rockies.
Fix that stuff, and I'd be willing to bet that the idle issue wil no longer haunt you.
Fix that stuff, and I'd be willing to bet that the idle issue wil no longer haunt you.
11-08-2011, 08:53 PM
#11
On The Tree
Thread Starter
iTrader: (2)
Join Date: Jul 2005
Location: Cleveland, OH
Posts: 129
Likes: 0
Received 0 Likes
on
0 Posts
The AFR's seem to be pretty dead on at mid/high RPM's on throttle in OLSD with the VE table the way it is. I've had a hard time finding enough straight road and time to do a ton of logging... My (probably incorrect) logic is that just smoothing it out will make it look pretty, but won't make fueling more accurate.
11-08-2011, 08:56 PM
#13
On The Tree
Thread Starter
iTrader: (2)
Join Date: Jul 2005
Location: Cleveland, OH
Posts: 129
Likes: 0
Received 0 Likes
on
0 Posts
Wideband indicates that it's not. I've literally moved the VE's allll over the place, both low and high, in the idle regions. STFT's always act the same way.
O2's are new, plus I swapped them with another set to be certain and had the same results.
O2's are new, plus I swapped them with another set to be certain and had the same results.
11-08-2011, 10:53 PM
#14
TECH Enthusiast
Join Date: Nov 2006
Location: Katherine N.T Australia
Posts: 620
Likes: 0
Received 0 Likes
on
0 Posts
If it wants open loop at idle then give it to it. Idle stft are notorious for being all over the shop in larger cammed cars and even the wb. Ignore them there and just give the motor what it wants without getting to hung up on clean data.. To a point of course because if your VE looks ridiculously all over the shop. It no doubt isnt realistic.
11-10-2011, 04:26 PM
#16
If it wants open loop at idle then give it to it. Idle stft are notorious for being all over the shop in larger cammed cars and even the wb. Ignore them there and just give the motor what it wants without getting to hung up on clean data.. To a point of course because if your VE looks ridiculously all over the shop. It no doubt isnt realistic.
