Please help me with Code 52

[suprahero]

Long story not so short..................
I've replaced both knock sensors. I have bought the brand new wiring kit from Shaeff and installed it correctly. I have tried a different ecu. I have reset the computer numerous times. I still get code 52 everytime I crank it up and go down the road.

My question is this............Could my below average oil pressure be causing it to throw a code 52? I don't know if it can or not, but I'm grasping at straws. The car is an 89 automatic turbo. At idle the oil pressure is about 5psi. While driving on the highway it may go up to about 25psi. It will rarely go near the 40 psi range. Could the low oil pressure actually cause the engine to knock and therefore throw a code 52, or does the code 52 ONLY mean that the knock sensors aren't receiving a signal. Please help me before I set Vixens car on fire.........................I ain't kidding either.

 

[suprahero]

Recent mods include, upgraded ct26, walbro 255 fuel pump, aeromotive fpr, 550 injectors, newly rebuilt transmission. It had the code before all of this and it still has it now. The motor is a remanufactured motor from American Engines with a three year unlimited mileage warranty, but I'm not sending it back to them, cause they don't know anything about our cars. That is out of the question. I'm hoping some of our local SM geniuses can tell me something that I haven't done. I've been fighting this for a long time now, and it's getting old..................lol

 

[MKIII VIXEN]

Somebody please help him. I really love my car and would hate to see him take out his frustrations on it...........:1zhelp:

Thanks
Vonda

 

[rumptis]

When you clear the code and start the engine up without driving it does it come back or is it only after you drive the car?

Here is what could cause a True Knock.

To much timing
Low Octane or Crap Fuel
Carbon Buildup
Running Lean under boost
Wrong Temp Spark Plugs

I'm sure you have checked the timing a bazillion times
I'm sure you have had lots of gas go through it so the chances of having bad gas forever are very slim.
I'm hoping with those mods you have some type of piggy back to tune with and a wide band so you should know if its running lean or not.

If the tune is good and the timing is good then the only thing left would be the Knock Sensors them self.

To test these I would think you could turn the timing way down where you know there is no way it could knock and go drive it a little and see if the code comes back.

 

[suprahero]

I only run 93 octane in it, so I know it's not the gas.
I don't think there should be any carbon buildup in a new motor, and new plugs.
I don't have a wideband on her car. I have one ordered for my car and may install it on hers first, but even when it had stock injectors and stock fuelpump it got the same code, so I don't think that is it.
It doesn't do it under boost. The check engine light comes on when you give it gas leaving our driveway, way before boost.

I'm going to go outside and check the timing again, if my friend is home with his timing light. I would order another wideband if I thought it would help, but I just dont think that it's running lean has caused it. Maybe the timing is off. I haven't checked it in a couple of months, but it should be right. I'll post back later............Thanks to everyone.

 

[jetjock]

Here is what could cause a True Knock...

Knock will not cause this code. In fact in the technical sense it's a lack of knock that causes it.

 

[mazzer]

just set it on fire already..

 

[suprahero]

marshmallows anyone?


JeJock, that's what I was thinking I read a while back. I feel like I have tried everything and can't get rid of it. Someone will find a cure for ugly before I get rid of this code 52..................:nono:

 

[MKIII VIXEN]

just set it on fire already..

Don't tempt him. By tomorrow I may be just Vixen minus the MKIII........:biglaugh:

Thanks Jetjock and Rumptis for the information.

 

[rumptis]

just 1j after your done with yours.

 

[Shytheed Dumas]

Jay, just to help you grasp at a few more straws, could the low oil pressure and/or code 52 have anything to do with the oil/coolant screw up you had with the engine builders (I think it was)?

I don't remember the exact details of what happened, but it seems like that engine went through some really screwy things, and now you're dealing with a couple of really screwy things...

 

[MKIII VIXEN]

Jay, just to help you grasp at a few more straws, could the low oil pressure and/or code 52 have anything to do with the oil/coolant screw up you had with the engine builders (I think it was)?

I don't remember the exact details of what happened, but it seems like that engine went through some really screwy things, and now you're dealing with a couple of really screwy things...

It was that the transmission fluid and oil lines were crossed. The transmission fluid was pumping into the motor. Yes the guys that built my motor were brilliant. That's why they won't get it back. Plus it took them 5 months to put the motor in and get the car back to us. It was one of those lesson's learned the hard way..............:3d_frown:

 

[dbsupra90]

yeah knock will not set a code. failure of the circuit will. are you sure both of the knock sensors you swapped are good?
how do you have the wiring grounded?
have you tried to jumper the knock sensor signals together at the ecu to see if the code goes away?

 

[suprahero]

Thanks Dave, I'll go check out everything you and I talked about...........lol

 

[tookwik4u89]

I have the same thing going on with mine Jay, and I have shielded coax from sensor to ecu, with shielding grounded on both ends, had code all summer......took it out for a drive last weekend and it never came on....wtf! I run premium or cam2, stock timing, ar3923's. I even used new connectors at the sensors.

 

[jetjock]

Fwiw shield grounding at both ends is not a good thing.

 

[tookwik4u89]

There are two articles on SOGI, one by Jeff Montigny says not to ground on ecu end, and the other by Manny Akim says ground on both ends. Weird, I will mess with it more this spring before racing, but I'm not worried about it at the moment, I monitor timing, a/f, temps, so i'm not all that concerned with it for now.

 

[steve_mk3]

Code 52 is caused by the ECU not detecting a signal from the KS's.
Understanding that there can only be a few problems
- Knock sensors
- wireing
-ECU

So if the KS's are good how about the connectors to the KS's?
It is very important to correctly ground the shielded cable at ONE end only. Make sure you are truely connected to ground and then check again.
If the KS's are good the wireing is good the only thing left is the ECU.

After being on this board for many years it seems that 99% of the problem is in the wireing and the grounding of the replacment COAX. The KS's put out a sinal in HZ that the ECU is looking for it is not a just voltage. That is why grounding the wireing is so important to make sure a clean signal is recieved at the ECU

The correct way to test this is with an osciliscope, but because it is a simple circuit you can just check all parts including the connectors and track down the problem.

I had this on my 88 after a rewire I would get 52 ever so often, it turned out to be the ground on the COAX that was the problem.

HTH

Steve

 

[suprahero]

Well, I did two things at the same time, so I don't know which helped. I disconnected the ground by the ecu. I also ran a jumper wire between the two wires where I soldered them together. Now it runs like it's got five hundred horsepower, well not that I would know what that feels like, but it is running alot stronger and not throwing any codes at all. I don't know which one helped it though and I've got to get ready for a birthday party. I will mess with it again later. Thanks for all of your help...................lol

 

[suprahero]

One more question about the grounding of these knock sensors. The grounding wire is wrapped around the knock sensor wire, but isn't actually installed in the connector. It's just wrapped around it. How does this ground anything? I'm not a genius nor do I play one on t.v., but I would like to know how this is suppose to ground anything. Thanks