[Mk2] [Turbo]code 51, knock sensor dead? and boost problem "paypal reward"?

[justarn]

hey all, just got my tubby out of its dusty hole (garage) after 6 months off the road for the mot. The engine is throwing a fault code 51, does this mean the knock sensors knackered or the fuels gone bad... any suggestions please? cheers ppl.

[Martin F]

Is 52 not the knock sensor fault code

[simpson_eh]

check the wiring first see if its corroded replace if needed you can tell if it sthe knock sensor try and drive it the ecu pulls the timing a lot

toyota have no way to test these as i found out after a blew one after 5 mins took it back and got an exchange but mine turned out to be a dead piston on number 3 after killing 3 knock sensore £128 + vat if i remeber or there abouts


see if you can borrow one just to see

[justarn]

ok cheers, can anyone tell me exactly where it is please?

Does anyone think it could be throwing the code because its been sitting for months and actually knocked a little when i got her started? the battery was completely flat and it took half an hour of jump starting!

i'll reset the ecu this morning c if that sorts it i thinks!

[simpson_eh]

its under the inlet manifold next to the vsv valve cant miss it 1 wire coming off it looks like a big bolt

so as its in the air you can see it

[alanmr2turbo]

error 51 is

No IDL signal, "NSW" signal or "A/C signal to ECU, with the check connector terminals TE1 and E1 connected

Trouble Area

A/C switch circuit
A/c switch
A/C amplifier
Throttle position sensor circuit
Throttle posittion sensor
Neutral start switch circuit
Accelerator pedal and cable
ECU

Thats from the TOYOTA Engine Repair Manual

[justarn]

cheers ppl, pretty sure it is the knock sensor on the jap engine fella??? what should i do, ive cleaned the plug and refitted, reset the ecu an its still throwing 51??? ive heard the wiring can decay? i'll try to get another knock sensor and run a new wire from the ecu...

can anyone explain which ecu wire is the sensor? does it run straight from the ecu?

if this fails what would you do if the engine were knocking? need only good advise please ppl? what would cause it to knock?

on a previous post ive had an ignition prob that still wont let me hold boost past 10psi, thus i have a restrictor fitted to the atmospheric side of the actuator. letting me hold at ten... any ideas would be greatly appreciated ty all.

[alanmr2turbo]

error code 52 is the knock sensor not 51.

I posted up what the 51 error code is.

[alanmr2turbo]

knocking would be caused by timing out or naff petrol

[alanmr2turbo]

[justarn]

sorry it is 52.... dunno where 51 came from lol. thankyou for your help, got a knock sensor and new cap in the post from gti chris for 52 pound! good price i think!

right, its got tesco 99 in it but has sat for a few months! should be good... ill check the timing and try to sort this damd boost prob next! think its to do with ignition, i've changed all the usual so maybe the coil an ignitor are the next port of call???

i will say my air fuel guage is made up of about 45 leds, 15 red lean, 15 yellow stock, an 15 green rich. does that make sense? well anyway on throttle, it used to sit right up the in the rich lighting only two green. now it lights about 10 all the way across stock and wont hold boost past 10psi????? thus the restrictor being fitted. this all came about after an ignition lead came unplugged and was throwing a 20mm spark, the full write up is under my jerky jerky post....

most unreliable car ive had owned a year been on the road for about 5 months!
new engine, ecu, afm, leads plugs dizzy n arm few times, amongst lots of wear n tear.... bought her as a project for 2500 and spent 3000 lol.

i will soldier on cause shes also the greatest car ive owned when shes a good girl

10 pound by paypal too anyone who solves my boost prob, dont count if the knock sensor fixes it though ha!!!

again thankyou all for ya time, much appreciated

[simpson_eh]

thew knock sensor will mess up your boost as it retards timing turbo will spin up very fast but will have no power at all

it puts it into safe/limp mode to stop any damage to the engine i ran it for six months like this and ended up killing a piston let alone the amount of fuel i used think i was getting about 30 miles to a tenner of petrol lol

[justarn]

well fingers crossed eh cheers dude!