Car is painfully slow. Help!

My car has been feeling very slow lately. I know, it's N/A, but it's definitely a lot slower than it should be. Attached is a log with tons of parameters (WOT 2nd gear pull is from 7000-22000 ms). I've ruled out a restriction in intake or exhaust. I tried another MAF sensor. Two things that jump out at me with this log are that peak air flow is 68 g/s (should be hitting 110-130). Also, engine load drops with higher rpms in the pull; it should be rising. This explains why my best acceleration now is shifting at ~2500 rpms.

 

Mods: High air flow intake panel, LWCP, header-back exhaust, phenolic intake manifold spacers, opensource tune on 91 octane.

 

Any ideas? I'm pretty clueless at this point.

romraiderlog_20131127_165739.csv

Can you post up a Learning View?

I've never actually used learning view. The download for it doesn't seem to be working on my laptop.

Put the tune back to stock.

 

Log the OEM tune and post log.

How are your brakes doing? Maybe they're seized.

And don't forget to check the diagnostic connectors so that they are separated.

No, brakes are not seized. None of them were burning hot after my last drive. Diagnostic connectors are separated. I will post a couple more logs soon.

Ok, here are two logs I took a few months back. First one is with the tuned map, second was taken with the stock map right after.

romraiderlog_20130817_140914.csv

romraiderlog_20130817_141108.csv

The aftermarket intake and stock map will cause issues.

The aftermarket intake and stock map will cause issues.

 

Just a different filter element should be no problem for the stock tune.

http://www.bedug.com/pics/smiley/smiley-confused1.gif

 

Nothing special in the logs - all seems to be OK except for the air flow. And the manifold relative pressure is close to zero when you have full throttle open.

 

Two things to check:

 

• That the TGV valves actually are open when they should be. (That should have given a MIL lamp if they didn't work, but just for the sake of it.)
  
• The fuel pressure.
  
• Clogged exhaust system.
  
• Bad PCV valve.
  

If the tune you have also contains a TGV removal fix and you still have them physically it might be a cause.

Thanks for the ideas. I'm 100% sure it's not a clogged exhaust system. I think it's safe to say the TGV valves aren't the problem considering I have no CEL; I'm not really sure how I'd check when they're open anyway. Bad PCV valve should cause oil in the air filter, oil consumption, excessive fuel consumption, and poor acceleration from my research. Since I only have one of those four symptoms, I doubt that's it. I'm not sure how I could check the fuel pressure. But with that, are you suggesting it may be a bad fuel pump, fuel filter, or injector(s)?

 

http://www.bedug.com/pics/smiley/smiley-confused1.gif

 

Nothing special in the logs - all seems to be OK except for the air flow. And the manifold relative pressure is close to zero when you have full throttle open.

 

Two things to check:

 

• That the TGV valves actually are open when they should be. (That should have given a MIL lamp if they didn't work, but just for the sake of it.)
  
• The fuel pressure.
  
• Clogged exhaust system.
  
• Bad PCV valve.
  

If the tune you have also contains a TGV removal fix and you still have them physically it might be a cause.

Since you had a tune it may be that the CEL was automatically blocked by the tune. Maybe not that easy to confirm that they work as they should, and you may leave them to later. One way to exclude them is to just remove the "butterfly" wings and keep the shaft - the car won't detect that they are missing. Search for "TGV Delete" for various methods if you go that far. But that's some additional work to do and not that easy.

 

The PCV is at least relatively easy to check - it shall allow flow in one direction but not the other. It may be that it's just working halfway, but it's hard to say. Easiest is to remove it, clean it with gasoline and make sure it works as specified. It means work but little cost. Also check all the other ventilation hoses so that they aren't clogged.

 

The fuel pressure is most likely the fuel pump or filter - but measuring the pressure both during idle and during a pull should give you a good indication of the health. If it was a single injector you should have misfires.

 

The exhaust system includes a possibly clogged cat. Even if the car consumes just a little oil it may be enough if it's during idle and low power to clog the cat - e.g. from aged valve seals.

 

Yet another device that can produce bad power is the EGR valve, but not every model has one, and it usually manifests itself as bad idle as well.

 

Also check the actual ignition timing with a timing light to make sure that it is really correct. What the ECU tells you and what it really is are sometimes two different things, but also make sure that the woodruff key actually is correctly in place and didn't get lost when you changed the crankshaft pulley. (long shot, but stranger things have happened) Be aware that this will make the timing look good with a timing lamp even if it's not.

 

Since it's at max throttle on a 2.5i you have problem I would exclude the possibility of a vacuum leak - not much influence from that during the conditions you have.

 

More evil causes belongs to the realm of ground down cams (which should be a new problem not seen here before) causing the valve lift to be lower than normal.

 

For woodruff key:

http://bbs.scoobynet.com/technical-topics-archive-427/783974-crank-pulley-wobbling-my97-uk-turbo-2000-ej20-engine-worn-keyway-repair.html

Working on yanking off the tube for the PCV valve now. I got the top end of it off, and right away I see that it's a little clogged with a milky white fluid. Does that mean anything?

Working on yanking off the tube for the PCV valve now. I got the top end of it off, and right away I see that it's a little clogged with a milky white fluid. Does that mean anything?

 

It only means that you shall clean it. Clean the hose as well. No point in worrying about it.

Unfortunately, I had to go back to college for a couple more weeks. Decided not to bring my car because it's slow enough that there's no fun taking it on the highway. So after all my exams are out of the way, I'll see if I can put an end to this problem.

You do realize it's a 2.5i and not a GT? Becz that would explain a lot.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

You do realize it's a 2.5i and not a GT? Becz that would explain a lot.

 

Yes, thank you for insulting my intelligence. I know it's not going to be as fast as a GT, but I can tell when it feels down on power compared to where it was. My data logs don't lie.

Bad O2 sensor and/or MAF? The O2 was killing the performance and MPG on my LGT.

Bad O2 sensor and/or MAF? The O2 was killing the performance and MPG on my LGT.

 

MAF sensor is fine. I don't think it would be a bad O2 sensor because if it was, I should get my power back in open loop, but the power isn't there anywhere in the rpm range. I did discover a tiny vacuum leak in the throttle body gasket. That wouldn't do it, would it?

MAF sensor is fine. I don't think it would be a bad O2 sensor because if it was, I should get my power back in open loop, but the power isn't there anywhere in the rpm range. I did discover a tiny vacuum leak in the throttle body gasket. That wouldn't do it, would it?

 

Couldn't help the problem.

Couldn't help the problem.

 

Yea, that's what I thought. It's gotta be something fuel related, maybe my fuel filter is clogged. Too bad it's inside the fuel pump and I can't really check it.

Took it to a mechanic today. He checked everything and it turns out my car is in mechanically perfect condition. He said his 04 forester 2.5i automatic would smoke my car. He said it might have something to do with my throttle control unit. It's gotta be something electrical/ ecu related. This is driving me absolutely insane.

Took it to a mechanic today. He checked everything and it turns out my car is in mechanically perfect condition. He said his 04 forester 2.5i automatic would smoke my car. He said it might have something to do with my throttle control unit. It's gotta be something electrical/ ecu related. This is driving me absolutely insane.

 

The mechanic is wrong. Something is limiting airflow. Two things... TGV and Throttle Body butterfly can do that. The tune, without some highly sophisticated and malicious intent, cannot.

 

So far, you haven't reflashed the ECU with an OEM tune, although I doubt it's the issue. Unless I'm mistaken, the logs you posted were post engine work, but prior to your posting this thread. They show your problem to be "mechanical," that is, the restricted airflow is a result of physical engine work.

 

So far, the Intake Manifold hasn't been lifted and the TGV system visually verified (a CEL is generated when the ECU commands a TGV action that isn't verified by the sensor, unless the CEL has been turned off by a tune. It is also possible to "fool" the system mechanically.).

 

And so far the TB butterfly action has not been visually verified.

 

Everything you've presented points to a physical constriction that limits airflow.

Yes, I've tried visually inspecting the butterfly valve, and I've tried the OEM tune. You might be right about the TGV getting stuck, that would explain everything perfectly.