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 

[Joey Mack]

Ok..... that adds more info..  do you have other issues? 

[Orange cv713]

1 minute ago, Joey Mack said:

Ok..... that adds more info..  do you have other issues? 

So I found a little bracket behind the radiator on the passenger side but nothing is on it beside the abs wires are zip tied to it but its has had alot of other things I have resolved along the way none real major I work it every day and it does well other than this fuel issue and it has done it since I have got it the ambient air temp sensor makes since to me because it don't do it until you drive it and it gets heat, on start up and cold its clean and certain times during the day it acts fine but that would make sense if it was wadded up in the engine bay somewhere or the wires where cut completely 

[Orange cv713]

17 hours ago, Joey Mack said:

Ok..... that adds more info..  do you have other issues? 

So I have a buddy that I haul with that has a 05 cv with a 370 in it I am gonna go and try to look at his this evening and one maybe figure out where it goes and 2 figure out where it goes in the wiring harness I have found 2 wadded up harness on top of my motor that are zip tied one is pretty long both with 2 prong plugs, but I'm not getting a lightning bolt so the circuit must be closed somehow 

[Joey Mack]

Can you peel back the loom on those wires and write down the code on them?  They should start with EJ or VJ, then a number, then a space and then a pair of numbers, then a space, then a decimal number. This code will tell you which ECU, the plug , and the pin number, then you can look at the V-Mac3 book to find that circuits purpose.  I have posted the charts before.  

[Orange cv713]

46 minutes ago, Joey Mack said:

Can you peel back the loom on those wires and write down the code on them?  They should start with EJ or VJ, then a number, then a space and then a pair of numbers, then a space, then a decimal number. This code will tell you which ECU, the plug , and the pin number, then you can look at the V-Mac3 book to find that circuits purpose.  I have posted the charts before.  

when I get home I will look and see what they say I did some looking on the internet, and found what the factory sensor looks like and I definitely don't have that the only harness to the front of the truck is the headlight and the abs I have a suspicion that the motor has been out of the truck before the pedal valve on the fire wall when I changed it was mangled all to pieces towards the engine most of the wiring is kinda just thrown wherever it will go it had a front end collision at some point according to car fax the bumper is definitely new and the radiator is new, but when I got it it seemed to me they where also chasing this issue it had new eups that where aftermarket of some sort but I figured that maybe since they wasn't mack that may have been the issue so I changed them to mack ones