I have been doing a lot of searching and reading around so feel I am quite clued up on common issues, I am aware this error has been covered many times!
I bought my first MR2 two weeks ago and unfortunately towards the end of the test drive it started hesitating and threw the error 52 knock sensor code.
I managed to negotiate a discount off the price (I felt it was already pretty cheap) so I took the car with the fault. I bought a new pattern knock sensor with some other bits as above from TCB parts
(found through this forum, thanks!) but this did not cure the problem. At this point the engine light would not come on straight away, I would get a minute or so of full power then engine light and limp mode.
If it turned ignition off and on again I would get the same, but wouldn't be 100% smooth a higher revs.I started going through possible issues so replaced the dissy cap, rotor arm
(as they where in poor condition anyway), fuel filter for piece of mind and I have got some ignition leads on the way, current ones are cheap looking after-market and look a bit worse for wear!From reading around I thought that the issue may be using a pattern knock sensor, so took a deep breath and ordered a genuine knock sensor from TCB.
Wanted to replace the above parts in case there was a issue blowing the sensor before fitting the expensive one! Reading through many forums regarding the error 52 one user suggested getting a new sensor and connecting it, not installing it in the engine just running a earth wire to the block instead to isolate the sensor so there is no way it could see any knock.
I did this with my brand new Toyota sensor (after ECU reset) and the error came up with a gentle rev as before. Engine light coming on a about 2.5-3K revs. I did a code check before engine start and revving and there where no codes present so happy ECU reset was done correctly.I am guessing this is showing the wiring is at fault.
I have just tested continuity on the wire now and it seems fine.
.. Maybe something wrong with the shielding?It's running standard boost.
I have done a compression test and is 140psi on 3 cylinders although cylinder 3 spark plug was in very tight so couldn't get that one out to test. Will try again after a good run out today see if the heat helps loosen it.I can't see any evidence of it running raised boost, all lines around the actuator look very old and original with no sign of clips being removed.
It was running worse before dissy cap and arm change so maybe that caused knock that killed the original sensor.
.... Now runs pretty smooth through the revs, a slight hesitation at about 2.5K revs but then smooths out but holding back due to safe mode. Before dissy cap change it was very jerky at higher revs..... Or maybe the original sensor is fine and it's purely a wiring fault... I am getting very frustrated with this now as running out of cash, and just want to drive it in this lovely weather!!
Any ideas?
