Lancer ES p0171!
Jul 14, 2014, 08:55 PM
#1
Newbie
Thread Starter
Lancer ES p0171!
Alright guys, just wanted to post my situation and see if I can get anybody's two cents. Basically I've got the p0171 haunting me for the past couple of months and I think it's time to get rid of it.
Currently no huge mods to the car except an injen cold air intake and a magnaflow exhaust and some suspension work. Never needed tuning due to the car running better with both on and it never threw any codes.
A couple months ago we were hit with a lot of storms here in Vegas which is rare and I tried to avoid the water as much as possible due to the CAI, but unfortunately I got caught and hydrolocked.
After some $$$ spent on a new engine and to pay a reputable shop, we had it back to the way it was.
Only ONE problem, p0171 stayed on. It comes and goes every now and then, it's usually this code followed by a the same pending code. What I've done so far is checked for leaks, replaced front o2 sensor, new MAF, and bought a short ram intake. None of this did anything. I've cleaned the injectors and have cycled through 87-89-91 octane. Nothing. I don't have mpg problems which led me to believe that it wasn't the o2. It worked with the previous intake and it wasn't the MAF which leads me to believe that it has something to do with the fuel system.
Shortly after replacing the engine, I had issues during cold starts where it would turn over, but die right away. Turned out to be that my battery had a bad cell so the car wasn't getting enough voltage to, I assume, build fuel pressure. Had a new one put in and a couple months later had a new alternator put in as well. The fact that the car would not keep pressure when it had lower voltage and is running lean to the point that I've gotten around 40 mpg tells me that my fuel pump or something in the fuel system is not running right.
I've looked all over for a situation similar to mine, but I've pretty much done everything I could with this code and in other forums. Am I okay to assume that it could be my fuel pump? And if so, are there any specific pumps that are better than others for daily use? Is there anything else that I could check myself? I guess the last thing I could do is get a fuel pressure test done to confirm, but before then, is there anything else that it could possibly be? Is there something else that the storms could have damaged besides the engine itself?
Any input is appreciated!
Currently no huge mods to the car except an injen cold air intake and a magnaflow exhaust and some suspension work. Never needed tuning due to the car running better with both on and it never threw any codes.
A couple months ago we were hit with a lot of storms here in Vegas which is rare and I tried to avoid the water as much as possible due to the CAI, but unfortunately I got caught and hydrolocked.
After some $$$ spent on a new engine and to pay a reputable shop, we had it back to the way it was.
Only ONE problem, p0171 stayed on. It comes and goes every now and then, it's usually this code followed by a the same pending code. What I've done so far is checked for leaks, replaced front o2 sensor, new MAF, and bought a short ram intake. None of this did anything. I've cleaned the injectors and have cycled through 87-89-91 octane. Nothing. I don't have mpg problems which led me to believe that it wasn't the o2. It worked with the previous intake and it wasn't the MAF which leads me to believe that it has something to do with the fuel system.
Shortly after replacing the engine, I had issues during cold starts where it would turn over, but die right away. Turned out to be that my battery had a bad cell so the car wasn't getting enough voltage to, I assume, build fuel pressure. Had a new one put in and a couple months later had a new alternator put in as well. The fact that the car would not keep pressure when it had lower voltage and is running lean to the point that I've gotten around 40 mpg tells me that my fuel pump or something in the fuel system is not running right.
I've looked all over for a situation similar to mine, but I've pretty much done everything I could with this code and in other forums. Am I okay to assume that it could be my fuel pump? And if so, are there any specific pumps that are better than others for daily use? Is there anything else that I could check myself? I guess the last thing I could do is get a fuel pressure test done to confirm, but before then, is there anything else that it could possibly be? Is there something else that the storms could have damaged besides the engine itself?
Any input is appreciated!
Jul 15, 2014, 05:10 AM
#2
Just FYI I'm trying an evo x fuel pump on mine (bought used here with 25k miles).
I'll let you know if my STFT levels off at idle. Mine is also not starting on the first try occasionally. It starts then bleh back off. I hit the key again and it stays running for the remainder of the day.
For the record of this code and the thread. My car is completely stock (oem intake and all).
I'll let you know if my STFT levels off at idle. Mine is also not starting on the first try occasionally. It starts then bleh back off. I hit the key again and it stays running for the remainder of the day.
For the record of this code and the thread. My car is completely stock (oem intake and all).
Jul 16, 2014, 05:58 AM
#3
Evolved Member
The p0171 is a code for system too lean. Here is a list of the possible causes from the manual.
Mass airflow sensor failed.
•Injector failed.
•Incorrect fuel pressure.
•Air drawn in from gaps in gasket, seals, etc.
•Engine coolant temperature sensor failed.
•Intake air temperature sensor failed.
•Barometric pressure sensor failed.
•Manifold absolute pressure sensor failed.
•Exhaust leak.
•Use of incorrect or contaminated fuel.
•Harness damage in injector circuit or connector damage.
•ECM failed.
Mass airflow sensor failed.
•Injector failed.
•Incorrect fuel pressure.
•Air drawn in from gaps in gasket, seals, etc.
•Engine coolant temperature sensor failed.
•Intake air temperature sensor failed.
•Barometric pressure sensor failed.
•Manifold absolute pressure sensor failed.
•Exhaust leak.
•Use of incorrect or contaminated fuel.
•Harness damage in injector circuit or connector damage.
•ECM failed.
Jul 16, 2014, 06:02 AM
#4
Evolved Member
Fuel pressure specs:
Standard value: Approximately 324 kPa (47 psi) at curb idle
Could be either your pump or pressure regulator if your is below spec. You just need to plumb an in line "T" with a gauge to check the pressure
Standard value: Approximately 324 kPa (47 psi) at curb idle
Could be either your pump or pressure regulator if your is below spec. You just need to plumb an in line "T" with a gauge to check the pressure
Aug 13, 2014, 10:12 PM
#5
Bump.
I'm having the same problem. I've replaced the MAF, new fuel pump and fuel strainer, checked vacuum hoses and still can't figure it out. This stuff stresses me out as I am broke living paycheck to paycheck and my plates are expired! Any advice would help. I'll post if I figure out a solution...
I'm having the same problem. I've replaced the MAF, new fuel pump and fuel strainer, checked vacuum hoses and still can't figure it out. This stuff stresses me out as I am broke living paycheck to paycheck and my plates are expired! Any advice would help. I'll post if I figure out a solution...
Sep 6, 2014, 05:24 PM
#6
Newbie
Thread Starter
Bump!
So i recently got my exhaust checked out when it fell off one of the hangers. When they checked it, another hanger had broken off leaving a big hole. They welded that back up and the car felt a lot better. Drove it off and the code was gone. I thought wtf $20 fixed the problem....for now lol the code came back two days later and is still coming in and out.
I have yet to check the fuel trims, but I'm hoping that when I do it'll point me in the right direction. Does anyone have the specs on what our reads should be as far as MAF, O2, air/fuel, and vacuum?
So i recently got my exhaust checked out when it fell off one of the hangers. When they checked it, another hanger had broken off leaving a big hole. They welded that back up and the car felt a lot better. Drove it off and the code was gone. I thought wtf $20 fixed the problem....for now lol the code came back two days later and is still coming in and out.
I have yet to check the fuel trims, but I'm hoping that when I do it'll point me in the right direction. Does anyone have the specs on what our reads should be as far as MAF, O2, air/fuel, and vacuum?
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