So, about a week ago as I was driving home from work, my car started sputtering under acceleration. I quick pulled over and shut it down. There was no CEL or EML, but when trying to start the car again, it would just turn over. After many attempts, I started to get a sputter out of it, then after many more, I got it to start and idle for about 20min. When revving the engine would then sputter and not get above 3k. I ended up having it towed home where I checked the plugs, coil, fuel pump, and fuel filter. I ended up replacing the fuel pump since the car has 122k miles and figured i'd get it out of the way while the tank was opened up, then i changed the filter as well since it was completely black. I noticed that the gas one the filter side was very cloudy compared to the pump side, and there was very fine gray material on where the filter cartridge was. Not sure if this is normal since I've never opened up a gas tank before. Anyways, after replacing the pump and filter, i primed a few times, then started the car with no issues. I took it around the block where it sputtered a little and the CEL came on, but after turning it off then back on, the CEL was gone and no sputter was present.

Fast forward to today, the first day that I took the car to work. I got gas, went to the grocery store, then headed to work, and about 5 miles later the car just died and all the lights one the tach/speedo lit up. I coasted into a gas station where I tried to start the engine with no luck.

Anyone have any ideas where I should go from here?

Could it be the MAP? Fuel Regulator? Bypass Valve? I'm lost and currently out of the water

 

Have you pulled the code from the CEL? That should give you a hint as to what is throwing it.

-Luccia

 

The gas on the filter side will be sorry but gray like metal material is not normal. If question the quality of the gas you used as well as the pump deteriorating and leaving behind some
Metal material. Which hopefully didn't pass the filter and clog your injectors.

Have you tested the fuel pressure? Check the fuel pressure at the fuel rail. See where that stands.

At this point you're just guessing at a fuel problem. You think that's it but you really haven't isolated any specific system of the car. It could be a bad coil and it just becomes a problem when it warms up. Check the terminals and confirm spark isn't an issue.

Check the stored CEL and see if it corresponds to anything you have already checked.

 

When i shut the car off the CEL was there, when i turned it back on it was gone.

 

I pulled some of the "dirt" from the filter housing and dried it and tested it with a magnet and nothing stuck, so I'm guessing its not metal. What options would I choose to view the stored CEL? I wasn't aware it stored previous CELs.

As Far as fuel pressure goes, I'm going to tear it apart this week and test it. When I replaced the fuel filter and pump, it started running perfect until today when it just shut down with no sputter or sign of struggle.

 

The CEL should be stored so plug in and see what it says.

-Luccia

 

any code reader will read the stored code.

 

Ok, I got the codes.

P0301 - Cylinder 1 Misfire Detected
P0638 - Throttle Actuator Control Range/Performance (Bank 1)
P0171 - Bank 1 System Too Lean
P0506 - Idle Air Control System Revolutions Per Minute Lower Than Expected

Now, where to start.....

 

I'd check the coil, plug and wire on plug one first. If it's running on 3 cylinders it could cause all kinds of other issues.

I had an issue where I installed a new coil, and after having a few too many beers installed the #3 and #4 wire in the wrong spots. It ran like crap and three an engine light. Oddly it only reported a misfire on cyl 3 and not on four. But it threw a host of other codes that were all caused by that misfire. So I'd check that first.

 

I checked all 4 plugs for spark and they were good. Also, all wires are going to the correct cylinder.

 

Just some things I have found:

P0301 - Cylinder 1 Misfire Detected (Look at post #2)
P0638 - Throttle Actuator Control Range/Performance (Bank 1)
P0171 - Bank 1 System Too Lean (I'd check the condition of your O2 sensor and also check to see if there are leaks in the system anywhere)
P0506 - Idle Air Control System Revolutions Per Minute Lower Than Expected

Common thing I'm seeing from a few of these is vacuum leaks. I'd smoke test the car and see if there are any. Hopefully some of these give you an idea of what could be the issue. Some may relate to others as well. Let us know what you find.

-Luccia

 

Thanks for the help. Based off of my searches last night, I figured I'd start with vacuum as well, in addition to cleaning the TB. I'll post updates with I find.....if anything, but hopefully something.

 

a vacuum leak likely wont cause a misfire code. You stated that you checked the coil and it was producing spark. But you likely tested it at an idle, where you said there's no issues. If I'm reading this correctly you said issues start around 3K RPM. Perhaps the coil cant keep up at that RPM.

 

Its still having issues at idle. I got it started after about 10 minutes of trying, and it would only hold idle for about 30 seconds, they start sputtering away and quit. If you slowly press on the gas, you can cover the RPM range, but if you press the gas too fast, it will want to die right away.

 

Here's a video. You can hear the blower whining when pressing on the gas. the only time you get a good rev is if you barely press on the gas and slowly increase pressure. At some points you can see the rpm drops to around 500rpm and wants to stall.

http://www.youtube.com/watch?v=q_QjKqB5s6k

 

this is probably a dumb question, but where does the mini get the data for the dash mounted thermostat? that's not the same sensor thats utilized by the ECM for any sort of fuel correction is it? Because you're reading -40*. If the ECM saw that it would be running insanely rich Id think.

Prob very far fetched, but seemed worth questioning.

 

Yeah, my thermostat broke awhile ago. It's actually mounted to the inside of the front bumper on the R53, not sure about the others. Unfortunately, when it's broke, it always reads -40.

 

Any other insight? Could it be a fuel pressure regulator issue maybe?

I had cleared the codes and got the car running again hoping to recapture any codes, and haven't had a CEL, but the car still won't keep running.

 

put a gauge on the fuel rail and see what its showing.

 

With the fuel pump primed, It's not even registering on the gauge, but with every prime it rises about 2psi. When I can get it started, it sits at 20psi when idling, and won't change even with a slow rev.

 

So maybe it's leaking fuel injectors? Maybe the pumps check valve won't hold the pressure? Or maybe your FPR is bad. You'll need a vac pump to test the FPR.

To test the pumps check valve you can get the car primed to the 20psi you mentioned and then turn the car off with the gauge on the rail. See how long it takes for the fuel pressure to bleed off. I think the book says like 20 minutes or so it should hold. If it's less then that then it's bad.

I'd be more inclined to say it's a leaky fuel injector. But that's just a guess. Since you said you can get it to level out by revving it up slowly.

 

The pressure was tested at the end of the fuel rail when those figures were found. I then tested prior to the regulator and had the same type of pressure issue. I moved on to the fuel pump, and got hardly any pressure there too. This is a brand new fuel pump so maybe it's just bad. I have no idea....

 

Turns out my fuel issue was a broken o ring in the fuel filter canister. But now That I got the car running, the idle keeps surging from 1k-2k RPM and misfiring. Codes are P1109 and P1242. The fun continues.