Hemi Running Issues

[Boony405hp]

Hey guys,

I mainly am on the forabodiesonly forum but occassionally pop in here. I did a 5.7 conversion on my A-body and am having some running issues.

A brief rundown of what it has:

Fuel system: Tanks Inc, in tank walbro 255lph pump and setup, to a corvette filter/regulator, 6.1 fuel rails with 5.7 injectors. -6AN braided lines.
Has a brand new battery. Hotwire auto full emissions harness (front and rear o2 sensors either side of the cats)

I constantly get 50psi on prime with this pump, but 58psi once the car starts. I thought my fuel pump might have been on the way out when I started having issues so I replaced with another brand new walbro 255lph and it also primes to 50psi and has the exact same running conditions. Issues are hard starting when cold or sat overnight, takes a few goes to get the engine to fire up, when it does fire up it coughs and splutters and stalls, after a few goes it does run and idle fine, it occasionally has a slight rough patch but then might sort itself out. Responds ok to light throttle application, but a decent hit with the throttle and it bogs right down and stalls. I have also replaced the filter/reg with another wix one with no change. The injectors are the stock 5.7's that came with the engine and had them cleaned, re-kitted and flow tested. Yet the car still runs like this.

Brand new battery, brand new pump, brand new filter/reg, new gas, rebuilt injectors, checked pcv valve, cleaned throttle body. It's starting to get beyond me and I don't know what to look for. No engine codes are up other than:

P0480 - Fan 1 Circuit Control
U0155 - Lost Communication with Instrument Panel Cluster (IPC) Control Module

These I believe would show on any car though as it can't see the factory dash or the factory fan setup. These have always been highlighted on the car whenever I plug the scanner in to the OBD2 port and cannot be cleared obviously.


An example of what it does till it get's running:
https://www.youtube.com/watch?v=e0bVj1DpofM&feature=youtu.be


I have live data but I can't make much sense of it.

If anyone has any suggestions or similar issues I'd love to know what you think.

 

[Average Joe]

Have you had anyone look at your tune. Did your ECM come with a tune in it? Most of the time when you get a flashed ECM it comes with a basic tune for your engine and you need to take it to a Professional Tuner or a friend who knows tuning and due the final adjustments. There should be an area when you plug into to the computer for starting parameters and other adjustments.Not sure what your running just giving suggestions.
Joe

 

[Boony405hp]

Have you had anyone look at your tune. Did your ECM come with a tune in it? Most of the time when you get a flashed ECM it comes with a basic tune for your engine and you need to take it to a Professional Tuner or a friend who knows tuning and due the final adjustments. There should be an area when you plug into to the computer for starting parameters and other adjustments.Not sure what your running just giving suggestions.
Joe

Hey Joe,

I haven't had anyone look at the tune, I thought it would be setup for a stock engine with a stock factory tune?
I'm running an 05 ram ECM. It was flashed by hot wire auto so I'd say it has the base tune on that.

I'm going to do a compression check today to see that something like a headgasket hasn't blown and causing the issues of the excessive white fumes coming out the exhaust.

I did pull the live data out at idle as well:

 

[kb67mopar]

Can you watch the fuel pressure with the engine running and hitting the gas? It sounds like the fuel pressure is plummeting as soon as you touch he throttle.

Also check your crank and cam position sensors. If they aren't reading right it will run horribly.