Gas problem, lean at idle and cruising
Gas problem, lean at idle and cruising
Hello guys, I have a problem with my fuel system.
The problem begon one month ago. In cold start the car run ok, the AFR is on 13.4 - 14.8 in crusing. After some minutes when the car s hot, the AFR goes to 17-18 ----- and not mark, very lean.
Last week I change the injectors and nothing. Yesterday installed a new fuel pump and nothing. What else can I change or check? this symtoms can be for fuel pump relay or pressure regulator?
The pressure is in 50 psi.... I set the fuel pressure to 60 psi and no change in airfuel, always lean, very lean.
I drove my car normal without boost (of course), and nothing wrong with his functionality.
Any ideas?
The problem begon one month ago. In cold start the car run ok, the AFR is on 13.4 - 14.8 in crusing. After some minutes when the car s hot, the AFR goes to 17-18 ----- and not mark, very lean.
Last week I change the injectors and nothing. Yesterday installed a new fuel pump and nothing. What else can I change or check? this symtoms can be for fuel pump relay or pressure regulator?
The pressure is in 50 psi.... I set the fuel pressure to 60 psi and no change in airfuel, always lean, very lean.
I drove my car normal without boost (of course), and nothing wrong with his functionality.
Any ideas?
Last edited by Mauricio Evo IV; Apr 8, 2019 at 09:52 AM.
Newbie
Joined: Mar 2019
Posts: 54
Likes: 14
From: MN
How did you come to the conclusion that it was the fuel system (obviously it's running lean, but did you do any testing to see that you are losing/not getting enough fuel)? Could be something else at play here.. I'm new to evo's, but I would check the fuel filter as well. Do you have a fuel pressure gauge? You may be losing pressure.. I've recently stumbled upon something called vapor lock while searching for the issues on my evo, I would look into that. https://www.evolutionm.net/forums/ev...ard-start.html
How did you come to the conclusion that it was the fuel system (obviously it's running lean, but did you do any testing to see that you are losing/not getting enough fuel)? Could be something else at play here.. I'm new to evo's, but I would check the fuel filter as well. Do you have a fuel pressure gauge? You may be losing pressure.. I've recently stumbled upon something called vapor lock while searching for the issues on my evo, I would look into that. https://www.evolutionm.net/forums/ev...ard-start.html
I started with the basics, so I take off the fuel filter and its fine. The fuel perssure when the car is lean at idle its always in 40-50 psi... Like I said, in idle with the engine run, I up the fuel pressure to 60 psi and idle its the same.
i will check the link that you post. Thanx man!
Newbie
Joined: Mar 2019
Posts: 54
Likes: 14
From: MN
Hello man! Thanx for you replay.
I started with the basics, so I take off the fuel filter and its fine. The fuel perssure when the car is lean at idle its always in 40-50 psi... Like I said, in idle with the engine run, I up the fuel pressure to 60 psi and idle its the same.
i will check the link that you post. Thanx man!
I started with the basics, so I take off the fuel filter and its fine. The fuel perssure when the car is lean at idle its always in 40-50 psi... Like I said, in idle with the engine run, I up the fuel pressure to 60 psi and idle its the same.
i will check the link that you post. Thanx man!
Mine is an Evo 4 with evo 8 ecu. Theres is not o2 sensor in my evo.
The car run normal but i know that is lean for the wideband. BTW the sensor of the wideband its new and spark plugs when I take it off, they are white... Not black when you have a lot of fuel.
The car run normal but i know that is lean for the wideband. BTW the sensor of the wideband its new and spark plugs when I take it off, they are white... Not black when you have a lot of fuel.