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Odd throttle response - feels like Limp mode - 20% max - read for more
Hey all - had the rs out for a drive yesterday and had 3 instances of a very odd behavior. Here is what happens:
After a few miles of cruise, i lose all throttle response, it’s like the ecu is holding the throttle to 10-20% amd car won’t rev under power past about 4k
Stop the car, restart it, car runs perfectly fine.
Drive the car hard, no issues. (Like it was fine all the way up and back Ortega highway)
This happened 3x in about 100 miles driving.
No cel, no weird noises, no dash lights, temps, oil pressures etc are fine. Car runs fine otherwise. Recent has at a high traffic station. Etc. throttle pedal is fairly new, maybe 5k miles on it.
I’m going to go down to the garage in a bit and pull codes with durametric and see if anything is pending. I’ll also run the tb position tests. Look at cams and knock data….
Has anyone seen something like this? Did some searching and couldn’t find anything. The only thing close was a poster who had a limp mode condition due to a faulty knock sensor wire.
Ok as you can see above i have some stored codes
cleaned maf and throttle body
maf is newer
tb is original
pedal is newer latest revision
inspected plugs and wiring they look ok
will inspect pedal tomorrow and ensure wiring ok
tomorrow will do a deeper check of the wiring, make sure for that i can see from top and bottom side no issues, will reseat TB, Maf, pedal and main harness plugs, etc.
could be a bad tb too…. will TRY to check before i start throwing parts at it :-)
Totally different vehicle but I've this happen on one of my Commercial Diesel rigs and it was some sensor in the gas pedal. Had to buy a new gas pedal assembly.
. Making sure it wasn't some other random update part I hadn't heard about while away from 997 land.
Hopefully it's something simple.
Maybe, I looked at my records and I replaced it with an 02 iteration and its been super seeded with an 03 version.
Originally Posted by DJN
Chris, I think you are just too damn tough with the throttle pedal....
Time for another new one!
Maybe although when looking at the details it seems the implausible code came from the TB.
Originally Posted by grizfish
Just guessing you will find an intermittent connection during your foot pedal check. Pushed pin, or whatever.
I dunno, maybe, it's been installed for a few years now... I do recall it's not hard to fit, but I also recall slicing my hand in the process on some trim piece. :-)
I'll do a little more hunting and debugging this afternoon. I can pull pedal easy enough and hook it up to a meter or scope to check function.
Well as i recall the gas pedal is a pain in the ***. Inspected harnesses best i can in engine bay. Reseated all plugs. They are all fine and no wire damage. Pedal is latest 03 revision. Cleaned maf and throttle body. Going for a drive to see if it will happen
and if does will pull codes then.
If it does will start with throttle body replacement first. Then it goes to shop to put on a lift and inspect rest of engine bay
Not sure if this will help, but a previous owner of my car had damaged either some MAF wires or TPS wires (forget which), and it caused a loss of power and eventually limp mode when I hit some bumpy road. Crazy enough, it also caused the oil pressure gauge to act erratically. Taping up the wire solved the issue. So, I think maybe look for wire damage with a fine toothed comb!
Replace gas pedal, I had this problem. There are 2 sensors in the pedal, if they don’t agree then RPM limp mode is initiated. This was on another car a new Aston Martin but many of these parts have the same functionality.
01-30-2023, 06:53 PM
Odd throttle response - feels like Limp mode - 20% max - read for more
. Making sure it wasn't some other random update part I hadn't heard about while away from 997 land.
