Engine Going Into Limp Mode?

[myr332]

Hi,

Just from a context perspective, I drive an 2001 R34 GTR V-Spec II.

Need some advice. Just before Christmas my car started having performance troubles. I do quite long drives, and after driving from Canberra to Sydney my car started entering into limp mode - it idles fine, but as soon as I accelarate the engine starts to cough and splut and has no power. At this point the engine light (sometimes) comes on. Oil levels are fine. I pull over, turn the car off, then turn the car back on and it works fine again for 30 minutes or so.

So one of the ideas from a mechanic I go to was that it is likely to be with the Coil Packs / Spark Plugs. I have replaced those and the issue is still happening. I've spoken to a few other people who have suggested maybe an issue with my O2 sensor or Airflow Metre.

Wanted to get some thoughts on this issue, and whether anyone has come across this before? I guess what I am after is a technique to troubleshoot to determine what is causing the issue - the coil packs cost me $650 so I'd prefer not to spend more money than I have to in order to get it fixed. So any advice would be of assistance.

Thanks,

G.

[femno]

Air Flow Meters.

Try giving them a clean with afm cleaning spray. If that doesnt work try swapping with someone else.

[Flargh!]

Have you checked if there are any fault codes in the ecu?

[myr332]

Have you checked if there are any fault codes in the ecu?

No I haven't.. I have a PowerFC - assuming plugging in the hand controller and replicating the issue will tell me that?

[myr332]

No I haven't.. I have a PowerFC - assuming plugging in the hand controller and replicating the issue will tell me that?

Okay, last night I did my own troubleshooting per some suggestions here. Popped off the intake, took out the AFM's and gave them a spray with AFM cleaning spray. Hooked up the Power FC hand controller and took it for a drive... after about 20 minnutes the problem reoccurred again. Checked the hand controller and couldn't see any engine error codes on the summary page. Not sure how to dig any deeper in the controller without breaking things.

So... back to square one.

Also i was finding a fair amount of oil inside the intake... blow back by the looks of things, however there did seem to be a bit of it.. it was pooling up a little in the air filter box in one of the corners, and leaking down into the engine bay. looked like there was a bit more than there should have been although I'm not sure what's normal having never done that before.

Any thoughts?

[paulr33]

are you sure its 'limp mode' ?

if the ECU runs in limp mode the engine check light comes on and stays on

this means a sensor is out of range and is giving a bogus signal, ie 0.0v etc

if you see the engine check light on then look at ETC, SENSOR SW CHECK on the hand controller (while the light is on)

the dead sensor will be highlighted with a black background (nice and bold)

then you will just need to check out what is wrong with the sensor

for the sensor names you can read the PFC FAQ in my signature