[Alabamatoy]

Anyone got a procedure for testing the sensor? My FSM doesnt seem to have anything on it - or I cant seem to find it.

If nothing else, does anyone know what an ohmmeter should read on a good one?

 

[Alabamatoy]

Thanks - that's exactly what I needed....

 

[GaryGreco]

Straight from the manual there ,nice post

Oh hey Alabama here is LC Engineering's post on where that sensor should go http://www.lcengineering.com/TechNotes/TechNote14.htm

 

[bobjohnson]

jasonmt, what year manual is that out of?

you might check this link out too. http://www.cybertrails.com/~bestinthewest/autotips/995Toy88Knock.html

 

[GaryGreco]

My experience with knock sensors is wirng connections at te snesor and the ecu, i think i had one where the sensor was bad. Out of 10 different vehicles,some had really bad gas and the ecu could not retard timing enough to stop it from pinging.

It would be wise to check the timing and watch it during the acceleration part of drivng if you can ,and see what is happening regarding timing if this problem keeps occuring with the ecu giving you a knock sensor code.


IT all related to frequency
HOpe this works ..



gary

 

[GaryGreco]

Jason.
Yup looks like that here mitchell is my guess as well ,

Am trying to scan some factory tsb's and old technical electrical stuff we were given by the factory engineers way back. I 'll scan some in periodically and try to post what is pertinant..ya what ever that spells...lol

Important too....
I tried to cut and past from my mitchell cd and it wont let me, if you have a trick let know .

Gary

 

[bobjohnson]

Gary, maybe you can point me in the right direction. I've had some knock issues for a while now. I have been running premium gas and have the timing retarded 5 degrees, 0 at idle with the connector shorted. I've swapped out the sensor with a junk yard unit, I grounded the shielding wire like in the writeup from the link I posted. I swapped the egr valve and modulator. I swapped the tps, I had to adjust it every month it seemed like. It still pings. I'm looking for the next step to take, should I buy a new knock sensor?

 

[jasonmt]

Jason.
Yup looks like that here mitchell is my guess as well ,

Am trying to scan some factory tsb's and old technical electrical stuff we were given by the factory engineers way back. I 'll scan some in periodically and try to post what is pertinant..ya what ever that spells...lol

Important too....
I tried to cut and past from my mitchell cd and it wont let me, if you have a trick let know .

Gary

Gary: The Mitchell I have is in PDF format so I just use the Text and Image select buttons to copy/paste as required.

 

[Alabamatoy]

I cant do the knock sensor relocation mod without a) pulling the motor or b) cutting off the shock tower, do the mod, replace the shock tower. Every drill I have tried wont fit because of the shock tower.

SO, what I was thinking of doing was just trying to eliminate the knock sensor - all its doing is retarding my timing anyway, right? If there was a way to give the ECM the right voltage signal that its looking for so it senses no knocking but still sees a good sensor, then alls well.

Right?

 

[jasonmt]

I cant do the knock sensor relocation mod without a) pulling the motor or b) cutting off the shock tower, do the mod, replace the shock tower. Every drill I have tried wont fit because of the shock tower.

SO, what I was thinking of doing was just trying to eliminate the knock sensor - all its doing is retarding my timing anyway, right? If there was a way to give the ECM the right voltage signal that its looking for so it senses no knocking but still sees a good sensor, then alls well.

Right?

Certainly is possible, but what happens when you get a bad tank of gas or have another mechanical failure that causes knocking? The knock sensor is working to prevent detonation before you can even hear it happening. I would certainly be worried about engine damage if you bypassed this system. Detonation causes three types of failure:
1. Mechanical damage (broken ring lands)
2. Abrasion (pitting of the piston crown)
3. Overheating (scuffed piston skirts due to excess heat input or high coolant temperatures)

 

[Alabamatoy]

I would certainly be worried about engine damage if you bypassed this system. Detonation causes three types of failure:
1. Mechanical damage (broken ring lands)
2. Abrasion (pitting of the piston crown)
3. Overheating (scuffed piston skirts due to excess heat input or high coolant temperatures)

OK, point taken, but before I let this dead horse alone, if I am running 93 octane, and basically taking care of the engine (not overheating, clean filters etc) then these are really low risk, right? And the darned knock sensor is retarding my ignition who knows how much! According to the LCE site, the knock sensor can do damage as well.

Should I just leave it as is?

 

[GaryGreco]

Alabama ,
If this a LCE engine youhave they know thier stuff,i would try like hell to get that knock sensor working.

And although it seems like it really is no big deal ,with that ecu it needs to hear a certain signal to remain iin closed loop as jason said .

It only retards 4 degrees at a time and then listens for a few seconds and retards again if needed, this happens til it gets to 16 degrees retarded and then it stops .

Only because the ecu in this TCCS toyota system uses that and othe sensors to control timing,otherwise you would be able to do without it. And do manually, like old school,but that engine was a lot of money i would try real hard to make work right if were mine.

Let me know if i can help
gary