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View Full Version : For those who have experience with troubleshouting the SR20det..


sepulchral
10-03-2004, 06:32 PM
I have an s13 w/ SR20det, FMIC, Fuel Pump, Yommomoto chipped ECU, DP, Xhaust, BOV

4 Months ago my JDM guage cluster had the check engine light lit for a long time, I was on high boost one day and went into WOT and around 5,000rpms the car went into fuel cut, it sounded like a series of backfires, and power lossed completely, the light turned off, the car wasn't as fast as it was.

Turns out it was a clogged fuel filter, i replaced it, and bam car runs fine but never felt as fast. And my car idles funny at random times, it will drop to 400rpms and fluctuate but never die down.

This morning i checked my ecu for the first time it rang out error code 34 - the knock sensor, the car runs great on high boost never detonates, but never felt as fast. I changed ecus for the heck of it, reset the ecu and after a VERY short drive around the block the computer picked up the knock sensor error already. I heard no knock and didnt break 8lbs of boost.

So, would it be safe to say that my knock sensor could be bad, and because of this, the ecu detects it and retards the timing causing the bad idle, and feeling of power loss?

If my theory is probable im going to replace the knock sensor, is the SR20det knock sensor the same as the Sr20de's?

Please help and post any info on error 34 you may have.

THanks - MIKE

tErbo b00st
10-03-2004, 07:07 PM
I think your theory is correct.

I believe you can just disconnect the knock sensor as well as it should run fine....just to see if that is the problem. If it works then replace it. If not you have other problems.

sepulchral
10-03-2004, 07:12 PM
Thanks but do you think the sr20de and sr20det knock sensors are identical?

TurboB15sentra
10-03-2004, 07:45 PM
I have an s13 w/ SR20det, FMIC, Fuel Pump, Yommomoto chipped ECU, DP, Xhaust, BOV

4 Months ago my JDM guage cluster had the check engine light lit for a long time, I was on high boost one day and went into WOT and around 5,000rpms the car went into fuel cut, it sounded like a series of backfires, and power lossed completely, the light turned off, the car wasn't as fast as it was.

Turns out it was a clogged fuel filter, i replaced it, and bam car runs fine but never felt as fast. And my car idles funny at random times, it will drop to 400rpms and fluctuate but never die down.

This morning i checked my ecu for the first time it rang out error code 34 - the knock sensor, the car runs great on high boost never detonates, but never felt as fast. I changed ecus for the heck of it, reset the ecu and after a VERY short drive around the block the computer picked up the knock sensor error already. I heard no knock and didnt break 8lbs of boost.

So, would it be safe to say that my knock sensor could be bad, and because of this, the ecu detects it and retards the timing causing the bad idle, and feeling of power loss?

If my theory is probable im going to replace the knock sensor, is the SR20det knock sensor the same as the Sr20de's?

Please help and post any info on error 34 you may have.

THanks - MIKE

The knock sensor code will only be thrown if the circuit is broken.. IE: broken wire, connector, or broken knock sensor. The code will not be thrown if the sensor picks up knock. You can read it if you have a consult to plug in.. but it won't throw the check engine light. You either have a broken knock sensor, or a bad connection/broken wire. Check the plug... it's next to the fuel rail between the 3rd and 4th intake runners. A lot of times.. the wire will break off right at the pin, inside the plug. Other times.. it will break at the knock sensor. Common failure among older engines.. If the knock sensor is open circuit, and the light comes on... the ECU will pull timing back until about 5500rpm or so.. then, the ECU will ignore the knock sensor, and you will have restored timing maps. You may feel a boost in power at around that RPM if this is the case.. Anyway.. check the connections.. or get a new sensor.

Travis

sepulchral
10-03-2004, 08:17 PM
do you have a picture where the knock sensor is?

sepulchral
10-03-2004, 08:26 PM
And for the love of god does anyone know if the sr20de knock sensor is identical to the sr20det's?

PSI240SX
10-03-2004, 09:18 PM
Look at your intake manifold between 3rd and 4th runners you will see two grey connectors, a 4 wire one, and a two wire. The Two wire connector is the Knock Sensor connector. If you follow it down the wires go about a foot to the sensor which is screwed into your block under your intake manifold with a 10mm bolt. I pulled the starter out to get to it easier. I changed mine out before I noticed that one of my wires was split up near the connector. Check the wire first.

sepulchral
10-03-2004, 09:23 PM
hey man i apreciate it

PSI240SX
10-03-2004, 09:25 PM
np, sorry I don't know if its the same sensor as the DE uses though. I should have an extra one coming in this week. If you find out that you really need one, PM me.

Steeles
10-03-2004, 09:28 PM
I've got one laying around too :) came off my SR. Im not using it.

sepulchral
10-03-2004, 10:34 PM
are you trying to sell it ?
:angel:

sepulchral
10-03-2004, 10:36 PM
to replace the knock sensor do you think its necessary to remove the intake manifold? or would you go from under the car?

Steeles
10-04-2004, 08:26 AM
I havent worked under a stock intake mani on an SR so I couldnt tell you the best way to do it. I removed mine while my greddy intake mani was being painted.

but yes its for sale :) Im broke make me an offer I cant refuse.. I just found it too it s in a box up in my room.

sepulchral
10-04-2004, 09:20 AM
sry man i think it was the wiring. im gunna chefck it out later tonight ill let you know otherwise

sr240mike
10-04-2004, 11:08 AM
Here's an easy way to check if its the wiring or the sensor. Go to radioshack and buy a 1 mega ohm resistor and put it in the connector for the knock sensor in order to bypass it. Reset the ecu and if it still throws a code 34 its your wiring. Here's a writeup for the 300zx on how to bypass with pics. http://zhome.com/ZCMnL/PICS/detonationSensor/detonationSensor.html

sepulchral
10-04-2004, 06:55 PM
replaced knock sensor took 15min

SilviaT
11-18-2012, 12:42 AM
I had the same problem with my code 34 knock sensor. I replaced it (took 20 minutes w/e) and now it runs like a champ! It was tuned incorrectly before i had the engine rebuilt and when i had it tuned i turned down my boost from like 15lbs to 12 and AFTER i replaced the knock sensor. and now i'm having that boost cut problem you had! Should i replace my fuel filter? z32 Maf, z32 fuel filter i believe but its old. It pulls hard up to about 4500rpm then sometimes ill get absolutely 0 power in gear and itll gain all power back like 2 seconds later. I am getting code 12 for MAFS but its new the connection is just missing the C clip and is a weak conection.

fliprayzin240sx
11-18-2012, 02:06 PM
You bumped an 8 yr old thread, while the OP has been banned from this site for over 4 yrs and you think you'd get a reply back from him?