PDA

View Full Version : Cos5 help after loading tune car wont start without maf plugged in


Aint Skeered
July 18th, 2017, 08:59 AM
I switched to cos5 to go speed density. But with a smooth hose in place of the maf the car wont crank until the maf fails.sometimes 50 cranks to fo it which will kill a battery.
I have to do all tuning with maf in line then crank it. Once it fails the maf it will crank fine without the maf but its not convenient.
Any suggestions?
joecar
July 18th, 2017, 11:34 AM
Post your before/after tune files.
Aint Skeered
July 18th, 2017, 12:03 PM
Joe i wish i could. I'm on a boat until next Tuesday. I have the lap top but can not post from it. Only from my phone.
Even Geoff at engine power systems who was helping me was baffled. Never had 1 do this going cos5
joecar
July 18th, 2017, 12:19 PM
Check that table B3647 has been correctly populated (because it will contain data from the previous OEM table B3605 which has a different axis)...

B3605 is ECT x MAP <--- previous tune
B3647 is RPM x MAP <--- new tune (COS)

the cold ECT data will show up as low RPM data, this is way to rich for the engine to run.
Aint Skeered
July 18th, 2017, 12:26 PM
All set at 1.0 in 3647 until 95 and 100 kpa
Aint Skeered
July 18th, 2017, 12:34 PM
http://img.photobucket.com/albums/v249/chad12345/Mobile%20Uploads/20170718_202545.jpg (http://smg.photobucket.com/user/chad12345/media/Mobile%20Uploads/20170718_202545.jpg.html)
joecar
July 19th, 2017, 05:07 AM
photobucket is not showing your pic.
Aint Skeered
July 19th, 2017, 11:56 PM
I sent it in pm
Aint Skeered
September 7th, 2017, 12:01 AM
I fixed the issue. First cell in maf calibration set to 15 so it would provide enough fuel to start. Work's great now
joecar
September 7th, 2017, 04:31 AM
I fixed the issue. First cell in maf calibration set to 15 so it would provide enough fuel to start. Work's great nowThat's because in some cases the PCM doesn't fail the MAF immediately...

good fix, I saw that on LS1tech yesterday and I was trying to locate this thread... thanks for updating.
Aint Skeered
September 10th, 2017, 02:40 AM
Thanks Joe.
69camaro5speed
September 11th, 2017, 02:44 PM
https://forum.efilive.com/showthread.php?26255-Cos3-01270003-to-Cos-5-02020005-Wont-start-now/page2
I posted about this a while back I up the lower areas in the maf to fix this
joecar
September 11th, 2017, 09:04 PM
Thanks, I cross-linked these 2 threads.