Built 408 need idle tuning help - on a SD Tune
Thread Starter
TECH Apprentice
Joined: Apr 2016
Posts: 313
Likes: 16
From: Lincoln, NE
Built 408 need idle tuning help - on a SD Tune Here's a run down of the motor:
Heads - AFR Mongoose 230cc / 62cc
Injectors - 60# FAST
Intake - FAST 102MM
Throttle Body - FAST 102MM
Plugs - NGK TR55
Fuel Pump - Aeromotive Stealth 340
Block - LQ9 4.03"
Cam - Comp 243/251, .624/.624, 111+1 LSA, 110 ISL Block - LQ9 4.03"
Crank - Lunati 4.00" Stroke
Pistons - JE 4.04, 12cc Dished for 11:1 compression
Rods - Lunati 6.125" H-Beam
Transmission - 4L60E, Finish Line Level 5
Converter - Yank 3600
Rear - KTRE 3.73 12 Bolt
I'm green here so here's my questions,
1. Rough idle till it runs for about 3 minutes almost acts like it's flooding itself on startup. But after idling or driving for a bit seems to clean out.
2. If I come to a quick stop maybe due to an unexpected red-light it stumbles and will want to die. Another example backing out of driveway and going from reverse to drive wants to die and will. But if I ease up to a light or stop sign car runs just ok but won't die or act like it wants to. I will try and get a log hopefully next week as it's still sitting at the transmission shop waiting on its Mark Williams Accu-Bond Alum Driveshaft and Mark Williams Yokes.
But I can go by and get a cold start idle log if that would help at all.
080716-1315.hpt
Heads - AFR Mongoose 230cc / 62cc
Injectors - 60# FAST
Intake - FAST 102MM
Throttle Body - FAST 102MM
Plugs - NGK TR55
Fuel Pump - Aeromotive Stealth 340
Block - LQ9 4.03"
Cam - Comp 243/251, .624/.624, 111+1 LSA, 110 ISL Block - LQ9 4.03"
Crank - Lunati 4.00" Stroke
Pistons - JE 4.04, 12cc Dished for 11:1 compression
Rods - Lunati 6.125" H-Beam
Transmission - 4L60E, Finish Line Level 5
Converter - Yank 3600
Rear - KTRE 3.73 12 Bolt
I'm green here so here's my questions,
1. Rough idle till it runs for about 3 minutes almost acts like it's flooding itself on startup. But after idling or driving for a bit seems to clean out.
2. If I come to a quick stop maybe due to an unexpected red-light it stumbles and will want to die. Another example backing out of driveway and going from reverse to drive wants to die and will. But if I ease up to a light or stop sign car runs just ok but won't die or act like it wants to. I will try and get a log hopefully next week as it's still sitting at the transmission shop waiting on its Mark Williams Accu-Bond Alum Driveshaft and Mark Williams Yokes.
But I can go by and get a cold start idle log if that would help at all.
080716-1315.hpt
Thread Starter
TECH Apprentice
Joined: Apr 2016
Posts: 313
Likes: 16
From: Lincoln, NE
But I did go probably 50-60% and car was real responsive and didn't stumble coming off that much throttle. It just seems to have this issue in really low rpm's from 800-2000 and if I'm real abrupt, but coming to a stop easily it can hold onto an idle much better.
Teching In
Joined: Mar 2016
Posts: 31
Likes: 0
From: Nebraska, The Good Life.
Like I said I am not a pro by a long shot, but your throttle cracker table is all 0's, you may want to research that a bit. It could be rich in the cold tables, are you using a wideband?
