Ai 427 intermittent fuel issue

[Orange cv713]

3 hours ago, fjh said:

have you checked the fuel pressure ???

So hear is some more ignorance on my part I haven't found a port to check pressure so do I take the return check valve out and tap in there 

[Joey Mack]

There is a 1/4" pipe plug behind the overboard breather. You can tie in there, if the plug wants to come out, or you can 'T' into line going in to the block below the #4 cylinder... 

[R.E.D]

2 hours ago, Orange cv713 said:

So hear is some more ignorance on my part I haven't found a port to check pressure so do I take the return check valve out and tap in there 

 

[R.E.D]

Test for static pressure and under load. If you get hose long enough,you can zip tie it to the windshield wiper and drive it around the block.Dont remember the most minimum pressure requirements but someone here will chime in.

[Joey Mack]

60-80 PSI. it used to be 100, but that pressure was blowing out the orings. That plug may fight you, but it is directly in to the fuel gallery.

[Orange cv713]

1 hour ago, Joey Mack said:

60-80 PSI. it used to be 100, but that pressure was blowing out the orings. That plug may fight you, but it is directly in to the fuel gallery.

Okay that is awesome thank you and I chased the wires out of the computer for the ambient air temp sensor and it was the ones I suspected that are dead head with a empty plug in the end 

[Joey Mack]

I forgot to add that the fuel pressure regulator is the 45 degree fitting that i said you can 'T' into...  if the fuel pressure is low, towards 60 or less and you are not making oil do to fuel dilution, then you need to replace that regulator...  then go from there with road tests...

[Orange cv713]

Okay so sorry for the long break I have been swamped lately, but a little update so I have changed the fuel pressure regulator fuel pump and had eup code uploaded in the ecm and installed a new intake humidity sensor so at this point I am leaning towards ecm, every fuel part is new 

[Orange cv713]

So something I have not thought of but could a fuel temp sensor or a inlet air temp sensor cause this 

[fjh]

1 hour ago, Orange cv713 said:

So something I have not thought of but could a fuel temp sensor or a inlet air temp sensor cause this 

Not sure on that! But  If it has an engine brake try unplugging it at the heads! there are some other mechanical issues that could be the cause ! Stuck injector or  a remote possibility of  broken rocker bolts! 

[Orange cv713]

4 minutes ago, fjh said:

Not sure on that! But  If it has an engine brake try unplugging it at the heads! there are some other mechanical issues that could be the cause ! Stuck injector or  a remote possibility of  broken rocker bolts! 

Well it has new injectors and it did the same with the old ones it just had overhead run with new rocker bolts installed and it was the same before and after it's definitely a timing issue of some sort all the cylinders are the same temp at idle 

[fjh]

K just thru it out there just in case know stone left unturned!