Results 1 to 19 of 19

Thread: 2021 Hellcat Hot Restart Issues

  1. #1
    Potential Tuner
    Join Date
    Nov 2022
    Posts
    3

    2021 Hellcat Hot Restart Issues

    2021 Hellcat has trouble hot starting on the new injectors. Cold starts always on the first crank. The injectors are some ~1700cc units I had made overseas by my intercooler supplier that I have used in a few different builds with great success so I pulled out my last set from storage and threw them in. They are usually super easy to scale and the process takes maybe 30 minutes on every other car I have tuned with them. I had noticed that sometimes even on the stock injectors it had trouble hot restarting but noting this extreme. Before the injectors I tuned the car to 950 wheel on water meth and nitrous with straight pipes. These cars are a dream to tune, just not with 1700's it seems which I think is probably due to being a returnless fuel system. It seems as if the fuel is vaporizing in the rails and lines... when I test the fuel pressure at the rail with a gauge it spikes to over 100 psi when the car is hot and it wont restart until I fully bleed the lines of fuel and reprime. Fuel trims are under 10 percent at idle so I don't think the data itself is the issue. People have mentioned leaky injectors but how would air enter the injector and fuel line while the rails are pressurized to over 100 psi? Here's the tune, its stock but with injector data and some codes cleared but I think that's it. This frustrates the hell out of me because the car should be making good jams and I can't even take it out on the town with this issue. Anyone run injectors this big on a returnless setup and if so what did you do to remedy this issue? ALSO! What the heck is up with the Startup INJ Pulsewidth Scalar!? My calculations as well as ID's put it between 22-26 and the software will only accept 16. I tried to workaround this by modifying the cold start table and rescaled it to 220 or something and added fuel in as well as delayed closed loop so the fuel system has a chance to get rid of the vapor before it starts trimming like crazy.
    Attached Files Attached Files

  2. #2
    Potential Tuner
    Join Date
    Oct 2015
    Posts
    4
    I am having the exact same problem. Has anyone figured out a solution. There is not a table present to regulate fuel pressure on startup in relation to coolant temp.

  3. #3
    Senior Tuner
    Join Date
    Jan 2022
    Location
    fountain valley
    Posts
    1,227
    Never been a fan of dead headed fuel systems. I no longer plan on building a turbo motor for my shaker but still have a bunch of fuel systems parts. Hmu if you need some fore rails, fittings, etc. It?s a lot of work (and $$) to do it right but you are seeing what can happen if ya dont. Good luck

  4. #4
    Tuner
    Join Date
    Mar 2021
    Location
    Yuma. AZ
    Posts
    82
    sound like the rails are vapor-locking due to heat soak, put heat wrap around the rails and fuel line going to the rail.

  5. #5
    Senior Tuner
    Join Date
    Jan 2022
    Location
    fountain valley
    Posts
    1,227
    If you go that route rather than adding a return try gold tape over whatever insulation you put

  6. #6
    Potential Tuner
    Join Date
    Apr 2022
    Location
    Germany, Stuttgart
    Posts
    7
    Hello any updates here? Having the same issues on my pullied Hellcat with FIC1000 injectors. Cold start is fine, hot start always on the 2nd push of the start button or with a light push for like 2 seconds on the accelerator on the first try. Running on pump gas

  7. #7
    Tuner Camaro6's Avatar
    Join Date
    Jun 2018
    Location
    Chicagoland
    Posts
    151
    Quote Originally Posted by HellcatV View Post
    Hello any updates here? Having the same issues on my pullied Hellcat with FIC1000 injectors. Cold start is fine, hot start always on the 2nd push of the start button or with a light push for like 2 seconds on the accelerator on the first try. Running on pump gas
    Give it more cranking airflow in the tune for that coolant temp area if a little throttle starts it.
    2018 Camaro SS, LT4 Fuel System, LT4 S/C
    2020 Ford Edge ST (93-E85 flex fuel tune)
    1999 Pontiac Firehawk
    1987 Chevy Caprice, 6.0L TT 4L80 AWD
    ***Only AWD box chevy in the world***
    Next Level Tuning and Performance
    Tuning email: [email protected]

  8. #8
    Advanced Tuner
    Join Date
    Aug 2006
    Location
    Arizona
    Posts
    353
    You can also try by adding 15-20% to the cranking fuel table in the warm areas.
    2009.5 PBM G8 GXP M6 W/Roof-Self tune, OBX LTs, Kooks axleback, LSA blower, cam,
    Monster LT1-SC clutch, flex fuel, 12 psi [email protected] 1,800 D.A
    2007 TBSS-Self tune, bolt ons [email protected], 1,900 D.A
    1991 GMC Syclone- Self tune/catback 12.8@104, 4,200ft D.A

  9. #9
    Quote Originally Posted by TunaSalad View Post
    2021 Hellcat has trouble hot starting on the new injectors. Cold starts always on the first crank. The injectors are some ~1700cc units I had made overseas by my intercooler supplier that I have used in a few different builds with great success so I pulled out my last set from storage and threw them in. They are usually super easy to scale and the process takes maybe 30 minutes on every other car I have tuned with them. I had noticed that sometimes even on the stock injectors it had trouble hot restarting but noting this extreme. Before the injectors I tuned the car to 950 wheel on water meth and nitrous with straight pipes. These cars are a dream to tune, just not with 1700's it seems which I think is probably due to being a returnless fuel system. It seems as if the fuel is vaporizing in the rails and lines... when I test the fuel pressure at the rail with a gauge it spikes to over 100 psi when the car is hot and it wont restart until I fully bleed the lines of fuel and reprime. Fuel trims are under 10 percent at idle so I don't think the data itself is the issue. People have mentioned leaky injectors but how would air enter the injector and fuel line while the rails are pressurized to over 100 psi? Here's the tune, its stock but with injector data and some codes cleared but I think that's it. This frustrates the hell out of me because the car should be making good jams and I can't even take it out on the town with this issue. Anyone run injectors this big on a returnless setup and if so what did you do to remedy this issue? ALSO! What the heck is up with the Startup INJ Pulsewidth Scalar!? My calculations as well as ID's put it between 22-26 and the software will only accept 16. I tried to workaround this by modifying the cold start table and rescaled it to 220 or something and added fuel in as well as delayed closed loop so the fuel system has a chance to get rid of the vapor before it starts trimming like crazy.
    give this a try is should fire up on hot start.
    Attached Files Attached Files

  10. #10
    Tuner in Training
    Join Date
    Jun 2023
    Posts
    12
    what kind of protection do you have for your starter against the heat?

  11. #11
    Potential Tuner
    Join Date
    Apr 2024
    Posts
    1
    My 2019 redeye will not restart hot.. shop has had it for 4 weeks. Basic mods were added, E85, 2.85 upper, 10% lower, FIC1200, 170 T stat. Car runs super strong, dyno came in at 940 RWHP. Both times I picked her up from the shop, drives great.. shut it down for car wash, 15 mins later it will not restart.. fuel pressure is too high and is preventing the injectors from opening.. that is what I was told 2 weeks ago.. still haven?t fixed my car. Any help would be appreciated.. I?m 8k and 4 weeks into mods that should take no more than 4 days and a tune

  12. #12
    Potential Tuner
    Join Date
    Dec 2023
    Posts
    9
    I have the same issue, let me know if you find a solution. It will start up fine. after I shut it off I have to crank it, it wont start but starter will try, then I wait 5 seconds and hit it and it starts. Not the biggest issue but I would like a solution as well

  13. #13
    Advanced Tuner
    Join Date
    Aug 2006
    Location
    Arizona
    Posts
    353
    The fix is in the injector data
    2009.5 PBM G8 GXP M6 W/Roof-Self tune, OBX LTs, Kooks axleback, LSA blower, cam,
    Monster LT1-SC clutch, flex fuel, 12 psi [email protected] 1,800 D.A
    2007 TBSS-Self tune, bolt ons [email protected], 1,900 D.A
    1991 GMC Syclone- Self tune/catback 12.8@104, 4,200ft D.A

  14. #14
    I was tuning a thumper recently with a 113 lobe separating angle in a 14 5.7 durango. I had the same exact issue. warm restarts sucked. what helped me and seeing you have the table too is adding 7 ft lbs to the 18907 table. Friction warm up located in Torque model>loss.

  15. #15

    What was the fix

    I have the same issue. What was the fix for your issue.

  16. #16

    What was the fix.

    Quote Originally Posted by SoFloRedeye View Post
    My 2019 redeye will not restart hot.. shop has had it for 4 weeks. Basic mods were added, E85, 2.85 upper, 10% lower, FIC1200, 170 T stat. Car runs super strong, dyno came in at 940 RWHP. Both times I picked her up from the shop, drives great.. shut it down for car wash, 15 mins later it will not restart.. fuel pressure is too high and is preventing the injectors from opening.. that is what I was told 2 weeks ago.. still haven?t fixed my car. Any help would be appreciated.. I?m 8k and 4 weeks into mods that should take no more than 4 days and a tune
    What the fix for your issue. I'm having the same issue.

  17. #17
    Tuner in Training
    Join Date
    Mar 2024
    Location
    Wisconsin
    Posts
    10
    Finally I am of use. If startup airflow increases don't fix, follow this:

    Engine > Spark > General > ESS


    Raise your Start Flare Gas Max (43231) table 80-240ms in small increments. Then slightly raise your Start Surface vs ECT and RPM (37842). We had all sorts of random startup issues, until these rather minor changes completely solved it.

  18. #18
    Advanced Tuner N2speed's Avatar
    Join Date
    Mar 2021
    Location
    Pompano Beach FL
    Posts
    314
    For those with this issue with FIC 1200D Injectors, there is an issue with the injectors themselves and FIC is aware of the problem and will swap them out for you.


    www.n2speed.com
    http://www.amp4x4.com
    [email protected]

    Dodge And GM Tuning Suppport
    Diablosport CMR | HP Tuners

  19. #19
    Quote Originally Posted by jakevandee View Post
    Finally I am of use. If startup airflow increases don't fix, follow this:

    Engine > Spark > General > ESS


    Raise your Start Flare Gas Max (43231) table 80-240ms in small increments. Then slightly raise your Start Surface vs ECT and RPM (37842). We had all sorts of random startup issues, until these rather minor changes completely solved it.
    What injectors are you using and what fuel are you running?