Ai 427 intermittent fuel issue

[Orange cv713]

So this probably needs to go in the engine and transmission forum but at this point its electrical so I have a 07 with a ai 427 and I believe it has a fuel timing issue that is intermittent, it fuel smokes at idle sometimes, honestly most of the time but there are times it does not but when it does it has a pretty audible fuel knock and gains blowby so I assume its loading up the cylinders, but driving it clears up the only odd thing it does driving is it studders every now and then when you shift gears or get back on the throttle hard, and some times holding at constant throttle it kinda floats around in the rpm, but I am pretty lost at this point I have had the overhead run last month and have changed injectors and eups all parts are mack, but nothing has changed, it has good power when actually driving its don't make oil, so the only think I can come up with is the computer is bad or maybe the eup harness have harness pulled right now and don't see any thing that jumps out at me, but I'm tired of throwing parts and hoping something stucks so I figure I would see what you guys thought 

[fjh]

15 minutes ago, Orange cv713 said:

So this probably needs to go in the engine and transmission forum but at this point its electrical so I have a 07 with a ai 427 and I believe it has a fuel timing issue that is intermittent, it fuel smokes at idle sometimes, honestly most of the time but there are times it does not but when it does it has a pretty audible fuel knock and gains blowby so I assume its loading up the cylinders, but driving it clears up the only odd thing it does driving is it studders every now and then when you shift gears or get back on the throttle hard, and some times holding at constant throttle it kinda floats around in the rpm, but I am pretty lost at this point I have had the overhead run last month and have changed injectors and eups all parts are mack, but nothing has changed, it has good power when actually driving its don't make oil, so the only think I can come up with is the computer is bad or maybe the eup harness have harness pulled right now and don't see any thing that jumps out at me, but I'm tired of throwing parts and hoping something stucks so I figure I would see what you guys thought 

So have you checked your fuel pressure? Another thing you can try is to put the ambient air temperature sensor in some ice water see if things change ! Located at the bottom of the radiator! Most times!

[Joey Mack]

In addition to fjh's procedures, can you carefully unplug the engine positon sensor while its running, and see if it shuts down, also do the same at the RPM TDC sensor in the flywheel housing. If you un plug one and the engine shuts down, check the other sensor and its wires for damage. A common issue is at the RPM TDC sensor wires. Many times i have found damaged wires inside the loom, if the loom is even still there, also, found weak contact inside the plugs.  

[Orange cv713]

1 hour ago, Joey Mack said:

In addition to fjh's procedures, can you carefully unplug the engine positon sensor while its running, and see if it shuts down, also do the same at the RPM TDC sensor in the flywheel housing. If you un plug one and the engine shuts down, check the other sensor and its wires for damage. A common issue is at the RPM TDC sensor wires. Many times i have found damaged wires inside the loom, if the loom is even still there, also, found weak contact inside the plugs.  

So I just unplugged both and a stayed running on both, I did just check grounds to the block and all where corroded I wonder if that could be a issue 

[Orange cv713]

2 hours ago, fjh said:

So have you checked your fuel pressure? Another thing you can try is to put the ambient air temperature sensor in some ice water see if things change ! Located at the bottom of the radiator! Most times!

And man I feel kinda goofy I have look this thing over from one end to the other and have yet to find the ambient air temp sensor 

[Joey Mack]

Good deal.  The ground bolt in front of the starter is notorious for comming loose. When you take the eyelets off, scrape the heat shrink glue offbof them.  You may want to look at the procedures for a 9-2 code.. I have posted it before, so maybey search it out on here...

[Joey Mack]

The A.A.T.S. is where fjh said, there is a thin bracket with a 1/2" hole. It clips in the hole.  I forget, but I think its on the bottom left radiator frame area..

[Orange cv713]

1 hour ago, Joey Mack said:

The A.A.T.S. is where fjh said, there is a thin bracket with a 1/2" hole. It clips in the hole.  I forget, but I think its on the bottom left radiator frame area..

Man I have looked all over the front of this thing and followed every wire to the front with no luck I am starting to believe its been cut off or something I have search the internet for pics of the location and came up with nothing but I am starting to lean towards that's the issue if its been cut off or someone has taped it up in the engine bay somewhere 

[Joey Mack]

Ok...  its 2 wires in 1/4" loom running down the left side radiator and may be coiled up and zip tied out of the way.  

[fjh]

18 minutes ago, Joey Mack said:

Ok...  its 2 wires in 1/4" loom running down the left side radiator and may be coiled up and zip tied out of the way.  

glad you remembered ! I for the life of me forgot which side and upper or lower! I do remember the fact we had an issue with one in the early AI engine! I think we ended up reflashing the ECU To get it to correct! symptoms were blue retarded smoke at idle! when ever it felt like it! PIA to track down! 

[Orange cv713]

49 minutes ago, Joey Mack said:

Ok...  its 2 wires in 1/4" loom running down the left side radiator and may be coiled up and zip tied out of the way.  

Okay yeah man I know this is crazy but its definitely not there so I bought this thing from a auction and it has been well melested in it life so I guess my next thing is trying to figure out where it comes out of the harness at