Chrysler 300c won't run after flashing tune

[Gagekelso]

Help! I bought my 2006 300c 5.7 with a blower and a custom diablo tune on it. It has been running and driving fine since I got it, but ive done a bit of work to it since and then recently I had it wiped of the diablo tune, and had a custom hp tune done at a shop (I won't name the shop, but its as reputable as a shop gets, it's just Sunday and they are closed so I can't ask for help). So that hp tune has been in my car and running great for the last couple weeks. I've been sending my tuner log files through email, and he just got my first revision back to me last night. Loaded it on to my car, it was idling rough but in drive it was fine, and I coasted down the road about a half mile (never gave it more than 10% throttle) and it stalled in 3rd as I was coming to a stop sign. Won't start. Sounds like it wants to, but sputters and won't run. So I flashed the tune that was on it before last night, and still won't start. Has anyone had this happen? What should I do?

[coanan]

How old is the fuel pump?

[Gagekelso]

Brand new fuel pump. Just put a OEM 392 pump in 2 days ago. Drove for a good long drive, drove it hard, filled with gas and went to work next day. Came home from work, car was running good. Flashed the new tune, started but idled rough, then died just down the road from my driveway.

[Gagekelso]

Brand new fuel pump. Just put a OEM 392 pump in 2 days ago. Drove for a good long drive, drove it hard, filled with gas and went to work next day. Came home from work, car was running good. Flashed the new tune, started but idled rough, then died just down the road from my driveway.

And the pump is priming as it should when I turn the key

[coanan]

Did the pump use all OE connections?

I put a pump in when I had the e-force on. One day it just quit, heard pump prime, would try to start. Opened tank and found the hose had burst.

[Gagekelso]

I have a 5.7, and I put a 6.4 fuel pump in per my tuners recommendation. He told me the wiring would be different and when I got the fuel pump from the dealership it had a diagram to switch 2 of the wires around. I checked those connections again, and the pump is priming as it should. But since it was driving good and then quit, I will open it back up and check those hose connections, that seems likely too.

[TheMechanic]

Did you do the throttle re-learn?

[Gagekelso]

Did you do the throttle re-learn?

I hadn't when I posted this. But I tried again today and did the relearn just to see, and no luck. I set an appointment to get my ignition and fuel system looked over at a shop in town. Just seems crazy that I drove it 2 times that day, parked it and loaded the tune, then it was idling rough until it died and now won't run. I'm looking into mechanical failure, but I have a feeling I'm wasting time and money and there's no way to know if it's tune related or not.

[TheMechanic]

I had a similar issue with a diablo tune on a 300C. Basically I had to reload the factory base tune and work back up. It was a year or so ago so my memory is a little faded but I think the issue I found was the MAP sensor was incorrect for the tune I loaded. Took me a couple days to figure that one out. Once I fixed that in the tune it fired right up

[Gagekelso]

I had a similar issue with a diablo tune on a 300C. Basically I had to reload the factory base tune and work back up. It was a year or so ago so my memory is a little faded but I think the issue I found was the MAP sensor was incorrect for the tune I loaded. Took me a couple days to figure that one out. Once I fixed that in the tune it fired right up

Did you have modifications done that changed something with your map sensor? Like I said, I bought my car with the supercharger on it. Also when I bought it, the MAP sensor behind the intake is nonexistent. The port to plug into is there, but the plug and wire is not. I thought maybe it was unplugged and tucked or fell down. But I have looked. It's been running and driving for the year that I've owned it, even after the first of the 2 hp tunes that were flashed to it. But ive always wondered why and where the map sensor is. My tuner does log MAP, so it must be somewhere.

[Gagekelso]

Also I have heard several instances where the pcm had to be flashed back to stock. But can't quite determine what causes that and if this is the same thing.

[TheMechanic]

The application I had was a turbo. If you are not running some form of MAP than you have to use MAF. Not sure if it has one as it did not in my application. I "F'd" with it for a while. Had to do some learnin' on the Dodge system to do this. One thing I learned was that the people that know Dodge are a VERY VERY tight lipped community. They do not share with others like GM. People here bend over backwards to share info and knowledge. Dodge not so much.
Logic says that if everything ran good before, and now that you changed the tune it doesn't that really reduces the odds of it being mechanical/electrical.
Have you tried any tune that previously worked?

[coanan]

The application I had was a turbo. If you are not running some form of MAP than you have to use MAF. Not sure if it has one as it did not in my application. I "F'd" with it for a while. Had to do some learnin' on the Dodge system to do this. One thing I learned was that the people that know Dodge are a VERY VERY tight lipped community. They do not share with others like GM. People here bend over backwards to share info and knowledge. Dodge not so much.
Logic says that if everything ran good before, and now that you changed the tune it doesn't that really reduces the odds of it being mechanical/electrical.
Have you tried any tune that previously worked?

His last sentence says he did. I'll stick with fuel pump.

Very true about the MOPAR tuning community.