14 degrees of knock retard!

[94V6ER]

I am using my Auto xray and i am chasing a sluggish pull in the tops of every gear change (m5). I notice that every time i shift i get 14 degrees of retard until i get way up in the rpm range. Ive switched from 87 to 89 to 92 gas but it makes no difference. The thing must be picking up something internal. Ive checked the connection its good and i hear no pinging when using 87. The sensor must be working because it retards the timing. Can i remove the sensor from the block, plug the block hole and mount the sensor somewhere else so that it will not retard. I know detonation is bad but Im not worried so much because shes got 108000 miles and if one day she blows shes gonna get a rebuild. Saying that would this work in theory? I would reverse this if the pinging became audible inside.

Thanks Mike.

[94V6ER]

Anybody?

[Bird_Of_Prey]

Hmmm... Interesting, if it's on the shifts and diminishes, it *could* just be picking up some drivetrain chatter. But that's only if it really is knock retard. I'm not very familiar with OBD1, but i know OBD2 cars pull timing out on the shifts. How quickly does it return to 0 or close to it?

[strange_trp]

sensor may be going bad. or circuit from sensor to pcm. i would think this would be the most likely cause since the numbers are not responding to increased octane fuel.

[v6maro]

<blockquote>quote:</font><hr>Originally posted by 94V6ER:
I am using my Auto xray and i am chasing a sluggish pull in the tops of every gear change (m5). I notice that every time i shift i get 14 degrees of retard until i get way up in the rpm range. Ive switched from 87 to 89 to 92 gas but it makes no difference. The thing must be picking up something internal. Ive checked the connection its good and i hear no pinging when using 87. The sensor must be working because it retards the timing. Can i remove the sensor from the block, plug the block hole and mount the sensor somewhere else so that it will not retard. I know detonation is bad but Im not worried so much because shes got 108000 miles and if one day she blows shes gonna get a rebuild. Saying that would this work in theory? I would reverse this if the pinging became audible inside.

Thanks Mike.<hr></blockquote>


just curious as to what you are using to measure this?
-Steve

[94V6ER]

I am using as post says an Auto X-ray EZlink. It monitors real time data from the computer. Great tool! By the way I have moved the knock sensor from the block, plugged the hole, and grounded the sensor so that the computer senses no false knock. WOW what a difference no more retard and the car runs 100 times better. I still hve no pinging i guess just a over sensitive knock sensor. No ses light either.

Mike

[knowledgefreak]

could you take pics or make a technical write up how to on this for the non mechanically inclined.

YES the knock sensors are waaaay over sensitive.
Some may be to scared to do this but they can install and air/fuel ratio gauge and know if they are running lean or not. Knock sensors will not save you from blowing your motor 100% any ways.

[94V6ER]

Hey Knowledge freak,
This is a real easy fix for an oversensitive knock sensor. The knock sensor is located onthe passengers side of the block where the freeze plugs are. It is about 2" in dia. and has a squeeze on electrical connector. From the bottom of the car you can reach it without removing anything. Remove the connector and lay it aside. Take a 22mm deep wall socket and remove the knock sensor (hold on to it you still use it). Now get a 1/4" NPT pipe plug add some teflon tape and screw it back into the hole from where the knock sensor was. Next take some 12 gauge wire, strip back about 6" to expose the wire and wrap it around the threads on the knock sensor. Take a hose clamp and slide it over the wire you just put on the sensor and tighten. This wire is used to ground the sensor back to the car. Reconnect the elec. socket to knock sensor and use wire ties to hang the sensor from a suitable place so that it doesnt bang around creating false knock. Finally ground the oter end of the wire to the body and bam! no more false knock or retard.

[mike malloy]

this may be stupid, but how do you know if you have an oversensitive sensor. i don't have autotap or any other type of scanning tool. can you just do this to recieve better performance

[94V6ER]

I had been chasing a performance problem for months. When driving the car i would be going along give the car some gas and you could feel the car hesitate. It was like someone had flipped a toggle switch and turned off one of the cylinders. It was terrible. That was when i had enough and bought the auto xray tool for 165.00 from parts america.com. Everyone needs this tool. It was worth every penny to figure out the sensor was over sensitive and fix it.