Need some help diagnosing a fuel delivery issue on a turbo build
02-06-2013, 07:06 PM
#1
Need some help diagnosing a fuel delivery issue on a turbo build So I have the car in my sig put together and it has been running great. A couple weeks ago after about 10 minutes of idling in one spot it started idling super lean on me (20:1). It has a sumped tank so I figured it was just low on fuel so I added some and after that it seemed fine and idled back at 14.7:1. Now fast forward to yesterday. Took car out for a quick 10 minute drive and the car ran flawless. Came home and parked for about 10 minutes with the car shut off. Went back to go drive around again and after I fired the car back up it was back to idling at 20:1 again so WTF?
My fuel system consists of a sumped 98 tank, -10 braided steel line from sump to a magnafuel pre-filter, then to a Magnafuel 625 pump. From the pump to a post filter and then -8 braided steel line to the front of the car to the fuel rails. Aeromotive adjustable regulator and -6 return line to the tank. The fuel pressure is steady at about 52 psi at idle. Anybody have any thoughts on the sudden lean condition after a few minutes of running?
My fuel system consists of a sumped 98 tank, -10 braided steel line from sump to a magnafuel pre-filter, then to a Magnafuel 625 pump. From the pump to a post filter and then -8 braided steel line to the front of the car to the fuel rails. Aeromotive adjustable regulator and -6 return line to the tank. The fuel pressure is steady at about 52 psi at idle. Anybody have any thoughts on the sudden lean condition after a few minutes of running?
Last edited by tording99Z28; 02-06-2013 at 07:48 PM.
02-07-2013, 10:27 AM
#3
Yes the tank is vented with a -8 vent. The car has had this fuel setup for almost a year with no problems and then all of a sudden it just started this. My next step is to pull the filters and check them but I would think if it was a filter it would do it from the get go and not after running for a little while.
02-07-2013, 03:13 PM
#5
Fuel psi has been datalogged and holds steady at about 52 psi the entire time. The volt gauge in the car shows 13V or more the entire time but I don't think I have it added as a PID on HPtuners so I will have to look at that. You can definitely tell in the way the car is running it is running lean, in the way it sounds at idle and when you try to give it any gas to rev it up or anything it just falls on its face and will not go.