PDA

View Full Version : Hemi 5.7 running issues



Boony405hp
03-19-2016, 11:43 PM
Hey guys,

Recently did a 5.7 conversion on my A-body and am having some running issues (starting and stalling or stumbling)


A brief rundown of what it has:


5.7 Hemi with TR6060.
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. I haven't had the car on the road so I can't say what it runs like normally or on hot conditions.


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://youtu.be/tiEpvwEHbe4
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.

Cheers, Dave.

Tincup
03-20-2016, 11:14 AM
Hey Dave, here are a couple things to check. Make sure everything is grounded properly. The battery needs to be grounded directly to the engine block " not the body". You can then ground the body to the engine. Make sure both heads are grounded also. If all that checks out, try a different ecu, get one from a 2005 Ram 5.7. Good luck.

Boony405hp
03-20-2016, 04:35 PM
Hey Dave, here are a couple things to check. Make sure everything is grounded properly. The battery needs to be grounded directly to the engine block " not the body". You can then ground the body to the engine. Make sure both heads are grounded also. If all that checks out, try a different ecu, get one from a 2005 Ram 5.7. Good luck.

Is it possible for the other factory ECU's to be flashed yet? I am running a re-flashed 05 ecu at the moment, I do have the one that came with the motor which is an 07 charger. Only asking as if it does come to that I'm in Australia and it might be easier than sourcing and having one shipped.

I ran some extra grounds today as well. I noticed when the engine started up and was running, when I and gave it some decent rev's it stayed running, but it was very fumey from the exhaust (white) and looked like raw fuel dripping out the pipes as well (on a slight incline) as well as the right tail pipe puffing a little bit after I turn it off. Could it have a blown head gasket? I checked the oil and it appears to be nice and golden with no milkiness to it. Video off it running below.

https://www.youtube.com/watch?v=LjdlPIBLfSU
Blowing fumes

https://www.youtube.com/watch?v=5X9SBMswUmQ
Tailpipe after turning the engine off

Motorcitydak
03-20-2016, 04:46 PM
Are you positive that your fuel pump is still running after start up? You say 58psi when running so I assume that it is but honestly it all sounds like it is a fuel issue. In your video it fires right up then slowly dies, it makes sense that no codes are thrown if it were fuel since that is not an engine issue. Who made your harness and flashed the ECM? The one from the 07 Charger will not work correctly if it still has the security on the ECM unless you had the keys to the car, but the 05 truck ECM is the best one to use and what I have in my 1996 dakota, ECM and wiring harness are from Hot Wire Auto

Motorcitydak
03-20-2016, 05:41 PM
Also what controls your fuel pump and starter? The Hemi ECM wants to control both, should get a +12 when keyed to the on position and start position, equally important that when in start, the +12 remains in run position as well. Many older style key ignitions lose the +12 to the run position when in start position. The ECM should prime the fuel pump, as I believe I can hear in the video, then turn it off. It will resume the pump when the engine is running

Boony405hp
03-21-2016, 01:00 AM
Also what controls your fuel pump and starter? The Hemi ECM wants to control both, should get a +12 when keyed to the on position and start position, equally important that when in start, the +12 remains in run position as well. Many older style key ignitions lose the +12 to the run position when in start position. The ECM should prime the fuel pump, as I believe I can hear in the video, then turn it off. It will resume the pump when the engine is running

Hi Steve,

When the car will run I can hear the fuel pump humming away, THat's what my gauge is telling me it's running at so I can only assume it is correct. I also feel its a fuel issue as after a few goes it finally fires as though it's taking a few attempts for the fuel to get there and I also agree with what you are saying that a fuel issue would not throw a code. The harness and flashed 05 ram ecu are all from hot wire auto as well. I have a push button starter installed as they specified and the hotwire harness is feeding the fuel pump supply. I think from memory the pink and yellow wire either side of the push button starter. I turn the key around to run or ignition which in turn primes the fuel pump for 2-3 seconds and then turns off, I then push the start button which fires the car up.

Boony405hp
03-21-2016, 01:01 AM
I'm wondering if the hard starting and white fumes are some how related though?

sccacuda
03-21-2016, 06:28 AM
Do you have a scan tool that reads data? Look at your fuel adaptive's. Do a battery disconnect to clear them, scroll to short and long term adaptive's and start the car. Look at short term first. Is it going positive or negative? It will max one way or the other, depending on the issue, and then save the value to long term. Short term will reset to zero and again start moving. Need to know what it's doing.

Boony405hp
03-21-2016, 01:06 PM
Do you have a scan tool that reads data? Look at your fuel adaptive's. Do a battery disconnect to clear them, scroll to short and long term adaptive's and start the car. Look at short term first. Is it going positive or negative? It will max one way or the other, depending on the issue, and then save the value to long term. Short term will reset to zero and again start moving. Need to know what it's doing.

Hi Craig,

I plugged in my basic scan tool after the battery had been disconnected. This was at idle. It appears short term is negative and long term is positive.

https://static1.pt-content.com/images/pt/2016/03/Live_data_zpsvj0md5bk-1.png (http://smg.photobucket.com/user/Boony405hp/media/Live_data_zpsvj0md5bk.png.html)

sccacuda
03-21-2016, 03:05 PM
You need to watch these numbers. I think your still in cold start which is why you have opposing numbers. If you don't already know, this is how these adaptive's work. The NGC controller has the ability to increase or decrease fuel 66%. This is to compensate for engine wear, altitude, etc. Short term is the immediate "fix". These numbers should bounce between -5% to +5% under normal circumstances. If the engine is lean, the numbers go positive to reflect the percentage of fuel being added and vice versa for rich. Once short term "sees" a constant change over a certain amount of time, it considers the engine always needs this increase or decrease in fueling and saves it to long term. Long term actually changes the fuel map to whatever short term ask for, this then lets short term drop back to zero and start the small corrections again. Short term is for minor corrections and is not saved to memory, only long term. Fuel adaptive's are a great thing for diagnosing an engine issue, just remember they only work when the engine is in closed loop.

For example: Say you have an EGR valve stuck open. Your diluting the fresh air intake, requiring less fuel. Longterm will be zero, and short term will decrease to it's maximum of -33%, and after a few seconds, will store to longterm. Longterm will now show -33% and then short term starts decreasing again until it maxes at -33%. Both long and short will show -33%. If you had a fuel pump regulator with a pressure too low or a pump with insufficient volume, then the opposite will happen. Short term will add fuel, to a maximum of +33%, and once stored to longterm, will add up to an additional +33%.

Hope that makes sense. So I want you to watch these numbers when it starts to stumble. See if it's adding or subtracting, and by how much. This will give you a better idea of where to start looking.

The hard start issue sounds like your losing prime. When you turn the engine off, how quickly does the pressure drop and how low does it go?

Boony405hp
03-21-2016, 06:55 PM
Ok that makes a bit more sense, I will keep an eye on the fuel trim levels. I'll have to get it running today so I can warm it up for 5mins because I want to do a compression check on all the cylinders to see that the cause of the fumes out the exhaust and hard starts aren't something more major like a head gasket or something worse.

As for the losing prime, I filmed it once for about 10mins, primed the pump to 50psi, then left the key on and walked away. It dropped to 35psi after about 10mins at a rate of 1-2 psi per minute. Doe's that sound acceptable? The video is here but it's just of a gauge so nothing exciting: https://www.youtube.com/watch?v=GeAWCr2S9-8

Boony405hp
03-22-2016, 05:21 AM
Well I did a compression check and the results were as below:
Appears number 7 cylinder has a drop in compression compared to the other cylinders. Being a 9.6:1 factroy compression engine this would be what you'd expect to see compression wise 150-160psi?
https://static1.pt-content.com/images/pt/2016/03/10_20_2011_6_27_04_pm_zpszkxdsomx-1.jpg (http://smg.photobucket.com/user/Boony405hp/media/10_20_2011_6_27_04_pm_zpszkxdsomx.jpg.html)

The spark plugs were also very black:
https://static1.pt-content.com/images/pt/2016/03/IMG_4724_zpspubapkxk-1.jpg (http://smg.photobucket.com/user/Boony405hp/media/IMG_4724_zpspubapkxk.jpg.html)

https://static1.pt-content.com/images/pt/2016/03/IMG_4726_zps4krwzshc-1.jpg (http://smg.photobucket.com/user/Boony405hp/media/IMG_4726_zps4krwzshc.jpg.html)

https://static1.pt-content.com/images/pt/2016/03/IMG_4725_zpsdo4kovgn-1.jpg (http://smg.photobucket.com/user/Boony405hp/media/IMG_4725_zpsdo4kovgn.jpg.html)

https://static1.pt-content.com/images/pt/2016/03/IMG_4723_zpsstf9zd0h-1.jpg (http://smg.photobucket.com/user/Boony405hp/media/IMG_4723_zpsstf9zd0h.jpg.html)

sccacuda
03-22-2016, 05:45 AM
You may have a fuel washed cylinder. Leave the plugs out and let it dry. Do a cold compression check tomorrow and see if it evens out and comes up.
The first "hit" is as important as peak as is the quality of the gauge! Record what each cylinder "hits" on the first stroke, and then the peak. I usually like to count to 10 while spinning it. After you've run through them, go back and do just the first one again to see how it compares to the initial recording. Again, the quality of the gauge is important. If everyone is within 10%, I wouldn't be too concerned with it being lower than the spec, could just be the gauge not reading accurate. If that cylinder stays low, I'd leak it down. If you don't have the tester, bring it up on TDC, take the Shrader valve out of the hose on your compression tester, and using a breaker bar on the crankshaft bolt, hold the engine to prevent turning. Hook your shop air on the the compression tester hose and listen for the air. If you hear it at the exhaust pipe, throttle body, or dipstick, that will let you know where your losing compression from. May have an exhaust valve seat "falling".

Your fuel pressure bleed off numbers are with spec. Leave the gauge on overnight, and then key it on while watching the gauge. It should hit 50-ish instantly. If it hits mid 20's, then another key cycle hits 50-ish, you have a leak, either an injector, regulator, etc...

Boony405hp
03-23-2016, 02:31 AM
You may have a fuel washed cylinder. Leave the plugs out and let it dry. Do a cold compression check tomorrow and see if it evens out and comes up.
The first "hit" is as important as peak as is the quality of the gauge! Record what each cylinder "hits" on the first stroke, and then the peak. I usually like to count to 10 while spinning it. After you've run through them, go back and do just the first one again to see how it compares to the initial recording. Again, the quality of the gauge is important. If everyone is within 10%, I wouldn't be too concerned with it being lower than the spec, could just be the gauge not reading accurate. If that cylinder stays low, I'd leak it down. If you don't have the tester, bring it up on TDC, take the Shrader valve out of the hose on your compression tester, and using a breaker bar on the crankshaft bolt, hold the engine to prevent turning. Hook your shop air on the the compression tester hose and listen for the air. If you hear it at the exhaust pipe, throttle body, or dipstick, that will let you know where your losing compression from. May have an exhaust valve seat "falling".

Your fuel pressure bleed off numbers are with spec. Leave the gauge on overnight, and then key it on while watching the gauge. It should hit 50-ish instantly. If it hits mid 20's, then another key cycle hits 50-ish, you have a leak, either an injector, regulator, etc...

The gauge is brand new from SP Tools (Australian brand) I had the coil packs resting in overnight, it was pretty much the same, went to about 135, injected a little oil and it came up to 150. Saying that, so did the good one next to it that was 150 and went to 170 i think. I didn't do the rest at this stage.

I couldn't do a leak down test as I didn't have a fitting to thread in to the compression gauge hose, I'll try sort that tomorrow. What sort of pressure should you be trying to put in with the compressor?

Inside the radiator it appears as though there may be some oil or something, scaley on top and looks a little oil like. Not sure if it is or not.
https://static1.pt-content.com/images/pt/2016/03/IMG_4733_zpsifuyw8yv-1.jpg (http://smg.photobucket.com/user/Boony405hp/media/IMG_4733_zpsifuyw8yv.jpg.html)

https://static1.pt-content.com/images/pt/2016/03/IMG_4740_zpsv0g9efzh-1.jpg (http://smg.photobucket.com/user/Boony405hp/media/IMG_4740_zpsv0g9efzh.jpg.html)

https://static1.pt-content.com/images/pt/2016/03/IMG_4735_zpsthta0cvv-1.jpg (http://smg.photobucket.com/user/Boony405hp/media/IMG_4735_zpsthta0cvv.jpg.html)