Sythe

Recently had my engine rebuilt @ RR. Everything runs fine, haven't tried to rev it up past 4000rpm really, did rev around 5000 getting used to the gas pedal early on... no noticeable limitations to assume limp mode but had this code and P2259 which I know what P2259 is by searching. I only found one thread for P0328 but the user never resolved his/her problem.


Additional information about car:
New ignition coils, wires, running old plugs that are in seemingly decent condition (recommended by kevin @ RR because the break-in will most definitely foul a new set of plugs which would be a waste). Cleaned knock sensor during engine teardown.

I also only run 93 but there was a quarter tank of leftover gas in the car from the PO that I bought the car from (had a blown coolant seal) that I tried to siphon out before running the car but could not do so, probably sat in the car for a couple months which I'm hoping is the reason for the code. I plan to double check the ground points underneath the harness plate but I assume bad ground points would cause more issues than a knock sensor code.

Advice and opinions, please.

NotAPreppie

Here's the FSM page for P0328:
DTC P0328

Looks like it's the knock sensor. You definitely don't want to run without this. Make sure it's installed and plugged in. It should be on the driver side of the engine, just above the rear spark plugs.

KNOCK SENSOR (KS) REMOVAL/INSTALLATION

M A Z D A

Sythe

NotAPreppie

It's a knock sensor so it's basically a piezo transducer. It's easy to forget to reinstall because it's just a little wart bolted to the keg just above the rear spark plugs. It's also easy to forget to connect because there are a metric fuckton of wires and connectors not far away.

Sythe

h4h4 I love when people tell me what a knock sensor is.

I've swapped two FCs to LS and JZ. I'm beginning to realize that I could probably help myself quicker than asking here. I was hoping someone with experience with this code could give a quick answer on how they fixed it just so I have a starting point rather than going through the manual checklist but it seems that is truly the fastest answer.

NotAPreppie

Okay, well, good luck. Surely with your expertise you'll have it solved quickly without any added help.

Sythe

I'll be sure to post the issue for users who search when I figure it out.

Loki

iTrader: (1)

Does that mean you've eliminated the causes the service manual page lists? It's a pretty short list. Your knock sensor or its connector are damaged.

Also, if you're going to **** on people answering your question, don't worry about posting back

Sythe

Sythe

Also, posting from my phone doesn't allow for spacing of paragraphs, sorry.

0-TO-100_Real_Quick

If you lurk here long enough, you'll realize that Prep's answer is what 99% of people are asking for. Also, it would have taken an extra minute at most to include in your post that you're well researched on the topic, and maybe ask something more technical than "hey i got this KS code, what do i do?" Then you won't get answers like "How about checking the KS."

NotAPreppie

The difference between not being a jerk and being a jerk is this:

A jerk:
OP: Hey, I got this code.
Knowledgeable Rando in his free time: That code is caused by this. You can read about it here.
OP: Duh, I'm not some unlettered moron. This place sucks compared to another place. What can cause that code?
Knowledgeable Rando in his free time: (thinking OP missed something in his earlier reply) Well, here is a more basic breakdown.
OP: H4h4, I know everything about everything already and you're an ******* for helping me.

Not a jerk:
OP: Hey, I got this code.
Knowledgeable Rando in his free time: That code is caused by this. You can read about it here.
OP: Hey, thanks but I've already read that and checked those things. Any other ideas?
Knowledgeable Rando in his free time: Sorry, man, hopefully another more knowledgeable person will give you their free time to help you with your issue.

¯\_(ツ)_/¯

Sythe

You're right, but I will say that I did state that I cleaned the knock sensor during teardown. Anyways, I'm pretty sure I found the issue for my situation: A couple millimeters down the wire (from the connector), somehow pieces of the wire wrap has frayed off and potentially allowing the two wires to short each other out. I'm not sure how I missed this when cleaning it before.

Regarding above, I need to outline something for future readers.... NotAPreppie claimed that you don't want to run without a knock sensor which is true in many cases but I'll quote Racing Beat on this: "We have also tested the knock sensor system and found that though it is good, it can cause minor problems. The sensor seems to detect normal engine vibrations as "knock" (pre-ignition), and because if this, the ECU retards the timing. Unbolting the knock sensor from the #2 rotor housing (do not disconnect it electronically - this will cause an ECU fault and retard the timing.) usually adds a small amount of power (often 1+HP) by eliminating the random, unnecessary retarding of ignition. Of course, if the engine should experience knock, your unbolted sensor will never know it- but cars ran for many years without these sensors and survived".

I won't just plop mine off and say forget it but I would like to make sure that there is thorough information available if a user were to search and merely wished to unbolt theirs, which I would do if I had more ways to monitor my engine currently.