I own a 2005 Acura Tl 6 speed.

I am experiencing sogmifocant performance loss when the car reaches operating temps. Vtec hits way late (if it hits at all) and you can tell it's not varying near the timing it should. Although, the power loss is noticed at all points in the rpm range. It doesn't misfire at all though.

When the car has just been started in the mornings or after work, it drives beautifully. Very smooth acceleration and plenty of power, until it's at op temp again.

All cylinders are pulling great compression and the plugs are new. The battery has been tested and the alt is putting out 14.5 volts. I've also done the ecu reset with no avail. It was sea foamed 2k miles ago.

I don't have a scan tool or any way to look at live data. Can anyone point me in the right direction who has a little more personalized experience with these 3rd gen TL's? Also, does anyone know how I can test the upstream O2's with a DVOM?

Any help is much appreciated.

-Seth

 

Do you have anything that reads the OBDII?

I'm curious what intake temp and water temp reports when the issue starts to present itself, and how the vehicle transitions transitions from working to 'slow'.

I would imagine most people probe the O2's at the connector for the ECU. A pinout should be floating around somewhere. You'd need some pointy probes or wrap a bit of thin wire on the leads.

 

Zomgvtec,

I don't have any way to scan the obd...

Do you know what the correct values for the map sensor are?

 

Hmm.... my car (and others, as you can read in this forum section) have similar issues. Most people have attributed it to heatsoak, but I'm still chasing it down and not giving up. I never thought of the MAP sensor being the issue, but, now that I think about it, it could very well be the issue. I get more of a surge of acceleration at VTEC, but it doesn't sound like you are getting that at all... just sluggish all the way through the band?

Let me know what you find. I'm curious.

 

Pbook,

The feeling of hitting Vtec you nailed right on the money. Same issue I'm having. I don't think it'd be a factor of heat soak because as soon as the car hits op temp I get this issue.

From what I know, most cars are in "open" loop when the car is warming up. The ecu isn't jurisdicted by live data from the sensors at all, but of an average of the past drive cycles
Then once it reaches op temp, the car starts reading live data from sensors and adjusts fuel and timing accordingly. (Closed loop) ( I may have open and closed loop terms backwards I can't recall)

If I could look at live data this process would be so much easier.

So what sensors jurisdict fuel? O2 map and iat.

What sensors jurisdict ignition timing? Crank sensor, knock, and O2 I believe.

So if i knew whether my ignition timing or fuel ratio was off, this process would be much easier.

Does anyone know what jurisdict Vtec timing and engagement?