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.

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.

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

sound like the rails are vapor-locking due to heat soak, put heat wrap around the rails and fuel line going to the rail.

If you go that route rather than adding a return try gold tape over whatever insulation you put

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

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Originally Posted by HellcatV

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

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Give it more cranking airflow in the tune for that coolant temp area if a little throttle starts it.

You can also try by adding 15-20% to the cranking fuel table in the warm areas.

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Originally Posted by TunaSalad

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.

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give this a try is should fire up on hot start.

what kind of protection do you have for your starter against the heat?

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

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

The fix is in the injector data

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.