[MasterWang]

Mods
Jb4 G5 iso
DCI
Synapse CP+BOV
Fuel-it Stage 1 (Inline 255)

I've been having rough cold morning starts for the past couple of days. Rpm dipped and there were loud knocking/ticking noises coming from the engine bay. When the rough idle went away after a few seconds, the car drove perfectly fine without any issues. I tried to start the car this morning after it had been sitting for a day and it would not start at all. Checked with Jb4 and BT cable and there were no codes stored.

I've taken the e85 backed flash off, jumped started with another car, and added pump gas to bring content down from e70 to e30. Still wouldn't start.

HPFP and LPFP values seem okay and all spark plugs were changed almost 2 months ago.

Can't attach CSV files for some reason. Logs are attached to first post in this thread (http://www.n54tech.com/forums/showthread.php?t=28335)

Rough start video + log

Failed start video + log

[Boris@SMS]

Is your JB4 set to map 0? If not try map 0 and ensure that it stays on map 0 after cranking.
I'd also pull at least one plug to inspect it. I've seen new plugs get destroyed quickly with bad e85.
I know some others are thinking fuel delivery issues but your fp logs can pretty much rule that out.

[The1ontop]

Yeah if you afe in cold weather and runing high amounts of e85 it will give you a rough cold start but the not starting issue is concerning I would check the plugs it seems to me like a ignition issue here

[andydna15]

I had this exact same issue 2 days ago after flashing back to stock. I put jb4 back to map0 and added 6 gal 91oct. On the 2nd cold start it turned on fine, the first time I turned it on I heard knocking and felt like it was about to shut off.

[MasterWang]

Originally Posted by Boris@SMS

Is your JB4 set to map 0? If not try map 0 and ensure that it stays on map 0 after cranking.
I'd also pull at least one plug to inspect it. I've seen new plugs get destroyed quickly with bad e85.
I know some others are thinking fuel delivery issues but your fp logs can pretty much rule that out.

I've tried map 0,4, and 7.
I will check the plugs later today. What exactly should I be looking for?

Originally Posted by andydna15

I had this exact same issue 2 days ago after flashing back to stock. I put jb4 back to map0 and added 6 gal 91oct. On the 2nd cold start it turned on fine, the first time I turned it on I heard knocking and felt like it was about to shut off.

I was using e85 backend flash when I had the rough starts. It won't start now with or without the flash. Mine also used to knock at first but would turn on fine the 2nd time. Now it's just pooped:/

[///Mposter]

Check to see if the spark plugs are wet with fuel. They should be slightly wet after cranking and a failed start. If not wet, then it could be possible the injectors are not getting power to spray.
On the other hand if they are drenched in fuel then you may not have the spark signal to the coils.
I do not recommend putting a screwdriver in the coil to see if it is firing as it arcs to ground . Although it is a good visual inspection of it working , it has been shown to decrease the life of the coil or ruin it immediately .
There is also a tool that can be put inbetween the coil and spark plug to view the arc/spark and there are also proximity tools that can illuminate near a power to prove you are getting firing.