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Discussion Starter · #1 ·
I have recently had an ssue starting my built TH. Foot on brake, push start and the motor tries to start but just "stumbles" over and over. If I try again it will start but sometimes not. Any possible suggested solutions appreciated. Tuner stated he has seen this problem in Hellcats before.
 

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Discussion Starter · #4 ·
Water in the fuel? Are you using an ethanol fuel? How's it run and drive, once started?
No water in the fuel, running 93 octane, runs well after I start it


You running a chiller and/or e85?


Yes running a Forced Induction Interchiller and on 93 octane.

Took it to my tuner and he also pointed out the possibility of the Chiller, made a few adjustments to the tune, added more air or less fuel at startup and timing because I am runinng a catless system. Will see how that works out.
 

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Your tuner is correct, you are not the only one having start issues with the chillers. Mostly hot start issues?

From what I’ve heard, they are thinking it may be a sensor confusion issue due to the cold coolant and the pcm thinking it’s a cold start vs the actual hot start.


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Discussion Starter · #6 ·
Your tuner is correct, you are not the only one having start issues with the chillers. Mostly hot start issues?

From what I’ve heard, they are thinking it may be a sensor confusion issue due to the cold coolant and the pcm thinking it’s a cold start vs the actual hot start.


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Yes mostly hot start issues. You make a interesting point and wonder if tuners can address this issue. I must say that I like the FI Interchiller.
 

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Yes mostly hot start issues. You make a interesting point and wonder if tuners can address this issue. I must say that I like the FI Interchiller.


The scenario does have “potential” merit because a hot and cold start have two different fueling needs.

If I hear anything more I’ll report back to you, but this has stumped more then one tuner.




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Not sure it only did it that one long time to start and now it's never been the same it takes more time to start. The german dealership is horrible and don't really do anything they just say it's normal but I know there is a big difference after putting 8k miles on it and it starts totally different.
 

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I have the same issue with my TH E85 and a chiller. I would take up to 5 tries to get it to start some times. Had it re-tuned and my tuner threw more startup air at it which helped a ton. Still stumbles at startup but better, at least it starts. If anyone finds any solution Id be interested!! I also have the chiller drag pack.
 

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Do you have the ability to read the tune file and send it could have something to do with startup ignition timing. I was just going over a Trackhawk tune file vs a demon file and there’s a bit more timing added in the startup tables for alcohol. In HP tuners also check out the minimum spark tables Spark min vs time. Or if you like just let me know I’ll send you the two factory demon tune files I have one is for the car and the other is for the crate motor.
 

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Seems like the common factors are E85 and an interchiller. I’ve been running E85 for a few months with no issue but I haven’t installed my interchiller yet. I believe there is speculation that shutting off the engine with the SC IC fluid cold, that condensation is forming somewhere and this is what’s causing it to take the extra time to get started. The E85 may or may not be a contributor and it could just be that people that invested in the interchiller are all modified.
If someone could try the method suggested and report back, that would be awesome. I live in a pretty humid part of the country so I’m thinking that I’d be having the same issue when I put my interchiller in.
 

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I think you have something there. I have been driving the last couple of days with the AC off and the issue has gonna away. My drive is pretty short but I'm gonna try running the AC and turning it off a min or two before I get home like you suggest and will let you know. Also note I have the drag pack option installed.
 
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