Trouble getting hemi running right

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An exhaust leak can make a big difference in how an EFI engine runs. Where is your O2 sensor at if you don't have an exhaust? Most O2 sensors need to be ~12 inches downstream from the header collector to read accurately.
 
One thing to note on fuel pressure is that I believe the Megasquirt system wants a manifold vacuum referenced regulator. What that does is assure that the fuel pressure relative to the intake pressure is always constant, so you have a known amount of fuel. Say for instance you had a boosted engine running 10 psi manifold pressure. If you have a fuel rail pressure of 60 psi, when the injectors open they are only seeing a 50 psi different, so what you think you are getting for flow at 60 psi is not what you're actually getting. Manifold referenced regulators adjust relative to that. That being said, I would expect to see the rail pressure drop from 58 at idle, not increase, at least assuming you're running NA.

As for the other issues, I ran my system fine with open headers, but it was still on a rough tune. It sounds like you're having some kind of sensor issue. I would try doing a data log of all of your sensors through the Megasquirt and watch the traces to see what it's doing. If you are seeing huge spikes in the O2 or injector duty cycles it might point to an exhaust issue. It seems more like a "accel pump" issue to me at first impression though. You might consider posting on the Megasquirt forums with your data trace. They are usually pretty good about giving feedback.
 
also stock injectors and the 02 sensor is plugged into the threaded hole on the headers themselves I will try getting and exhaust system put on it and see what happens at that point anything as far as tunning is out of my skill set
 
dartboy73 said:
so the exhaust could defiantly be my problem
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You cannot have any leaks at the exhaust headers at the heads or it will totally mess up the A/F ratio as seen by the O2 sensor. Plus as other stated - you must run an exhaust connected to the header - otherwise it also screws up the O2 sensor. Suggest start here.
I'm also not sure what you mean that the port on the front of the intake is plugged? Does that mean you don't have a PCV valve installed? I've attached a photo of the stock PCV valve
You did the right thing by adding a filter onto the port by the oil filler cap. That allows clean air to flow into the crankcase - assuming that you have a PCV valve installed.
If your FP gauge pegs at >60 psi, something is wrong. If the pressure is 58-60, then that should be fine. I've attached a photo of the correct hookup for the filter/regulator return to the tank. Suggest double check that the 5/16" fitting in the center of the regulator goes back to the tank unobstructed/unrestricted.
My system is FAST, so I probably cant help you with the setup of your Megasquirt system.
Keep us posted on progress.
Jim
GM LS V8 Fuel Filter_Fuel Regulator Kit, 58 PSI.jpg


IMG_7529_1280x960.JPG
 
The one on the right is the one I have blocked off. I will check my fuel filter tomorrow if I get a chance

187019-4408352cc1ee9a3d7c47c35d0da87f75.jpg
 
RealWing said:
You cannot have any leaks at the exhaust headers at the heads or it will totally mess up the A/F ratio as seen by the O2 sensor. Plus as other stated - you must run an exhaust connected to the header - otherwise it also screws up the O2 sensor. Suggest start here.
I'm also not sure what you mean that the port on the front of the intake is plugged? Does that mean you don't have a PCV valve installed? I've attached a photo of the stock PCV valve
You did the right thing by adding a filter onto the port by the oil filler cap. That allows clean air to flow into the crankcase - assuming that you have a PCV valve installed.
If your FP gauge pegs at >60 psi, something is wrong. If the pressure is 58-60, then that should be fine. I've attached a photo of the correct hookup for the filter/regulator return to the tank. Suggest double check that the 5/16" fitting in the center of the regulator goes back to the tank unobstructed/unrestricted.
My system is FAST, so I probably cant help you with the setup of your Megasquirt system.
Keep us posted on progress.
Jim
View attachment 1715251909

View attachment 1715251907
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It’s about time. I knew you would have some good stuff for him.
 
Trying to catch up some as I do not frequent this forum much...

How about some datalogs and perhaps a tune file?

I have a 5.7L running on a Gold Box, I can probably look over your settings for a gut-check. I'll echo the other responses, you must have exhaust in order for your o2 to provide any reasonable information.

You mentioned the "pressure sensor" read 89? I assume you mean MAP, and if it's reading 89kPa with the engine running (and not at high load), then you have an issue there...

The MS does not "need" a vac referenced regulator, it'd be nice, but it's not your problem. I have the LT1 filter and allow the ECU to reference pressure and adjust accordingly. However, I put ~3,000mi on without any fuel psi ref.
 
Me again. So I got my exhaust on and it still is not running right still idles too high. When I hook computer up to it it says my air fuel ratio is at 19 and is red it says this before engine even started

20190802_210714.jpg
 
Still sputters when you touch the throttle and dies.
 
Any ideas? I notice my throttle position is at 8.4 even when its completely closed and my air fuel is in the red
 
that's normal they never show 0 because the throttle plates are slightly open to allow idle air just like a carb. does your set up have a 02 sensor?
 
man, I have to admit this is really Greek to me. I just remember having a bad ground on an FI Dakota, that made it run super rich.
 
I think the high idle with the closed throttle, and the erroneous O2 reading, are all pointing to an intake leak, or a problem with the AIS motor, if you have one, or even with the PCV.
And it's possible that the 23* of Idle advance, is bandaiding the issue.
 
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AJ/FormS said:
I think the high idle with the closed throttle, and the erroneous O2 reading, are all pointing to an intake leak, or a problem with the AIS motor, if you have one, or even with the PCV.
And it's possible that the 23* of Idle advance, is bandaiding the issue.
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I did have to pull the intake to run new heater hoses under it maybe it is leaking. I will look this weekend
 
So I changed the fuel filter regulator from the one I got from tanks inc to a Wix filter and the pump sounds better and the car now idles very well. It still seems to hesitate when you touch the throttle still but if you feather it you can now get it to rev up. It still pops all the time though
 
dartboy73 said:
So I changed the fuel filter regulator from the one I got from tanks inc to a Wix filter and the pump sounds better and the car now idles very well. It still seems to hesitate when you touch the throttle still but if you feather it you can now get it to rev up. It still pops all the time though
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Your air fuel ratio is way lean. Try adding more fuel in your fuel settings to richen it up some. Also your MAP sensor (Fuel load) seems low. You might have to swap the two outer pins in the MAP sensor connector. I had to do this on my 6.4 swap.
 
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