With foot on brake won't rev past 1k in D or R and starts to run VERY rough and cough / load up.

Was hitting 2500/2600 no problem but now not.

Sometimes have to disconnect "+" on the battery for a minute or it drops voltage with key to on from battery voltage to 2 volts which acts like a blown fuse but they are fine.

Idles around 750/800 rpms.

Automatic tranny.

Thanks

 

Why are you pressing on the throttle at the same you are pressing down on the brake when in Drive or Reverse? How does the tach/engine act if the car were in Neutral and engine reved? Also, when disconnecting the battery, you remove the ground cable first to cut off the power of the battery and "not" the positive. And there is no limp mode on the S4 that compars to the S5.

 

I guess I don't understand, are you trying to drive through the brake?

 

Not trying to drive through brake - should get to 2500-3000 rpms before it starts to hesitate, not 800 - 1k rpms.

In N it idles well and revs as high as you want to go. There is a slight hesitation around 1500, maybe 1800 rpms but goes right away.

Just disconnecting the ground on the battery did nothing for it, had to unhook the positive battery cable.

 

Its in the FSM somewhere, don't recall where at the moment, section 4 maybe.

 

No, WHAT are you trying to accomplish by revving in gear and the brakes held down?

Trying to burn up your torque converter? >_<

Does the car drive normally?

Edit, you just posted that message.. I'll look it up.
Edit2: NM.. You look it up ^_-

 

It seems to act like the anti theft is trying to keep it from being started and driven off but it is not connected anymore.

 

Car was running pretty good, adjusted the idle and tps and started running very well. Now it runs like ***, won't get past 1k in D or it dies.

Maybe a reason, the car was shut off and restart attempted with the idle initial set jumpered.
Then, these problems suddenly arose - sorry, forgot that part.

 

The 'WHAT' is a 'within spec' test , which it is not.

 

The coupler being jumpered is not a factor in this. The factory alarm would prevent the car from being started, period, as that is all it does, and are you sure you have the factory alarm.

And stop disconnecting the positive battery terminal first as it could lead to the battery exploding when the positive cable is reattached.

 

Is there actually a problem with the car, or not? Can you actually drive the car, or does it stop at 1k even with your foot off the brake?

 

Won't go past 1k in D or R, sputters and dies. In N it is fine.

 

No alarm, starter cut disconnected.

 

Is there a way to power down / reset ecu? Searched but only found FD related.

 

Never heard of having to depower the ECU to reset it. If you wanted to depower it completley then just key OFF and then pull the BTN fuse in the engine compartment. Now no voltage at all goes to the ECU. at all.

Pull the TPS plug apart and try driving it in D or R and see if the problem went away. A TPS that has a stuck plunger internally can give you the problem you described. Been there and done that twice in the past. Decoupling of the TPS plug let it rev up and made it driveable til the TPS got " fixed".

EDIT: Then again you say you can rev in neutal and all is well which makes my comments above not valid. Oh well.

I assumed no brake when in D or R during your failed rev attempt.

Really.......on series four there is no ECU reset ever needed. Initial set coupler should always be uncoupled when driving the car.

 

You "might" have damaged the Lock Up Relay which relates to the Torque Converter. As I understand it, if it is damaged it would cause the engine to stall. So you need to check the items related to the auto transmission such as ECU pins 1I and 1L. Pin 1L should read 12 volts in any gear and pin 1I would read 12 volts in any gear when the overdrive button is not depressed.

 

The initial set coupler was accidental. But yeah, disconnected TPS didn't change anything. Still rev'd in N and 1k ish in D and R.

Car won't go over 1k while driving and then starts to cough / sputter and wants to die until put back in N or P.

 

What is really weird is sometimes it will not get power w/ key to on. Main Fuse (80a) will have battery voltage from fuse box and when you put key to start the voltage will go to 2 volts. Disconnect the battery, let it sit for a minute, connect battery and it fires right up.

Edit: Main Fuse goes to 2 volts w/key to ON not Start

 

Are you using the volt gauge for this reading or a multimeter, and if a multimeter, then there is either a loose connection at the Engine fuse box or a loose ground. The Black wire from the positive battery terminal that runs to the Engine fuse box is connected to the fuse box on the side of the box closest to the battery. How about jiggling this wire and see if the voltage stays 12 volts constant or if it drops.

And if you are using a meter to read the two volts then "exactly" where are you taking this reading from.

 

Using a multimeter and checking the main fuse at the bolts that hold into the fuse box. The WL wire on the main fuse box drops the same voltage with key to on as well.

Poring rain right now, will jiggle it tomorrow.

 

The W/L wire can only have voltage if the Black wire from the battery is properly connected to the battery side of the Engine fuse box. So it must be this connection or the battery ground is poor. This ground runs to the driver's side fender so you might want to redo this ground by cleaning it up,and if so, remember to disconnect the battery ground cable first.

 

FSM 7b-19, 20

 

Thanks.
I understand why you were doing that test now... But I think it was the wrong test to try. Tis' a very misleading name. >_<

As for the car dying under load.. Not sure, sputter and die sounds kinda like when you run out of fuel.. Test all the sensors and then look at possible fuel supply issues?
:/ That's a tough one..

 

Fuel supply from pump to engine to good, went through that already.

Waiting for the rain to go away - lost the indoor shop i was using, the guy got booted for not paying rent. Don't mind getting wet I just don't like playing with electricity (of any sort) while standing in a puddle of water.

 

Quick question: When the car is at idle and you disconnect the AFM, should the car stay running or die?