sw20 check engine light

[FXGTV]

After driving the sw20 for about an hour home from work the check engine light came on, and stayed on. Usually this indicates overboost, and turning the car off and then on again fixes it. But after yesterday the first time the boost kicks in the check light comes on - turning it off and on again does nothing.
The boost is definately spiking noticably so im guessing something has gone wrong somewhere along the line. What are the simple things I should check to figure out the issue?

Thanks in advance.

[fivebob]

The wonderful thing about a Check engine light is that if you follow the testing procedure and check the codes it will tell you what is wrong without having to consult the dubious opinions on a forum

in other words Check the Codes then post the results, that saves random guesses from wasting your time

My guess is a broken knock sensor (code 52)

[FXGTV]

Haha, yeah fivebob, i was out doing the tests while you were replying Its come up with two difinitive fault codes, a 34 and a 52.
According to an mr2 FAQ site code 34 is is fuel cut off ue to excess turbo pressure.
And the 52 code you already know is an issue with the knock sensor.
So now what?

[FXGTV]

Upon further research (i googled ) i've read that that the fault code 34 can be caused by driving too hard on poor fuel. I was stuck in an area with no 98, so i was forced to get 95...i guess ill have to use up this fuel and wait to get some 98. Hopefully that fixes that code, and then its just a matter of fixing the knock sensor one

Learning is fun

[fivebob]

Haha, yeah fivebob, i was out doing the tests while you were replying Its come up with two difinitive fault codes, a 34 and a 52.
According to an mr2 FAQ site code 34 is is fuel cut off ue to excess turbo pressure.
And the 52 code you already know is an issue with the knock sensor.
So now what?

Good guess huh

Replace the knock sensor. Fix the overboost or it will blow another sensor. Do a compression test to see if you've damaged any ring lands.

[FXGTV]

I dont suppose you could give me a quick run down on how to replace a knock sensor could you?

[Mr Revhead]

1: get under car
2: unplug sensor
3: using the right size spanner (26mm?) unscrew sensor
4: install new sensor in the reverse manner

[fivebob]

3: using the right size spanner (26mm?) unscrew sensor

IIRC it's 30mm, a deep socket is a better alternative to a spanner.

Also be careful re-installing it, they're esay to break if you knock it on tighten it up too much.

[Mr Revhead]

yeah 30mm that rings a bell

iv always used the ring end of the spanner.
mainly coz i dont have sockets that big!

[FXGTV]

I saw a good thread on the nz mr2 site - all up it cost the guy $90 for a new sensor and to re-wire it so it would work. Its no biggie to not use genuine parts then. Ok, so whos got a sensor i can buy?

[FXGTV]

How bad is it for the engine if i drive it around till I fix it?

[flygt4]

pretty sure mr2SIK tried that and it didnt turn out well.

[FXGTV]

Hmmm - well i better get on to finding a knock sensor, and fast!

[MR2SIK]

pretty sure mr2SIK tried that and it didnt turn out well.

my engine lasted a good 6 or so months after blowing the knock sensor before it decided to lunch the big ends and blow the head gasket

but yea, not advisable, runs like a sack of unwanted xmas kittens, and cant be too healthy for it either

[FXGTV]

Its just really laggy when it coms to boosting. But when the boost kicks in the spike tends to shove your head back into the seat

[fivebob]

Its just really laggy when it coms to boosting.

Actually I think you will find that the boost builds quicker because there is more energy in the exhaust gas, but there is a lot less power due to the severe ignition retard.

But when the boost kicks in the spike tends to shove your head back into the seat

That will be becuase you're making too much boost, fix the overboosting problem before you join the "Dead 3S Society"

[FXGTV]

I've tracked down a knock sensor from an st183 - will this fit?

[fivebob]

I've tracked down a knock sensor from an st183 - will this fit?

Maybe if it's production date is after 91/08

Here's a list of the cars that use the same sensor

Code: Select all

HILUX SURF                       95/11-00/08  RZN18#
HILUX                            99/08-       REN169,174
REGIUS/TOURING HIACE             97/04-99/07  RCH41,47
GRAEVIA/GRAND HIACE              95/08-98/04  RCH11
DYNA/TOYOACE                     00/05-       RZU300,340. .EFI
CRUISER PRADO                    97/04-       RZJ9#
MR2                              91/08-93/11  SW20
MARK 2                           96/09-97/08  JZX101
CHASER                           96/09-97/08  JZX101
CRESTA                           96/09-97/08  JZX1O1
SOARER                           91/05-94/01  UZZ3#
SOARER                           94/01-96/08  UZZ3#
SOARER                           96/08-97/09  UZZ31
CROWN/CROWN MAJESTA              95/08-97/07  JZS155,UZS15#
ARISTO                           92/10-97/08  UZS143
CELSIOR                          94/10-97/07  UCF2#
HILUX                            91/08-95/11  VZN130
DYNA 200/TOYOACE G25             95/05-00/05  RZU100,140. .EFI
CARINA ED                        91/08-93/09  ST182,183. .GLIM
CELICA                           91/08-91/09  ST18#. .GTR,GT4,GT4RC
CELICA                           91/09-93/09  ST18#. .CV,GTR,GT4,GT4RC
CORONA EXIV                      91/08-93/09  ST182,183. .TRG
CORONA                           91/08-92/02  ST171. .GTR,GT
CAMRY/VISTA                      91/08-92/06  SV32,33. .GT
CROWN                            90/05-91/10  UZS131
CROWN                            90/09-91/10  UZS131
CROWN/CROWN MAJESTA              91/10-95/08  UZS14#
CELSIOR                          90/05-94/10  UCF1#


[Mr Revhead]

now theres a handy list.....



think ill FAQ this....

[FXGTV]

If anyone has a photo of exactly where the sensor is it would be appreciated. I'm having trouble finding it as i dont have access to any ramps or proper jacks at the moment. Its hard to look around when your 1cm away from burning your nose off on the exhaust