Time to rewire the knock sensor

[BSOD2600]

Alrighty, I'm to the point with my inconsistent knocking issues that I'm going to replace the knock sensor wire from the engine back to the ECU.

1) What gauge wire should I get? 18, 20?
2) Where does one get that single shielded wire from? radio shack, home depot, etc?
3) Where does one buy a NEW knock sensor connector to solder on?

[Legacy777]

18 or 20 gauge, either should be fine. You're dealing with very low voltage.

Not sure where to get the wire.

I would suggest reusing the existing connector and soldering it to the new wire. Like this (In the electrical sticky btw)

http://bbs.legacycentral.org/viewtopic.php?t=38796

[BSOD2600]

I'm having no luck finding ANY business in this city which has replacement wiring for the knock sensor. I've called over 10 places. Each business who doesn't have it, I follow their leads to others which they think might. Heck, even called up Anixter International (they sell wiring/connectors in bulk to the automotive industry) but the guy said he didn't know if they did have wiring that fit my description AND even if they did, couldn't sell it to me.

1) Since the shielding in the KS wire is only connected at the ECU and not to the senor itself, does a replacement wire need to be shielded?
2) Have any idea where I could find replacement KS wire?

[Mattheww044]

not sure if this helps, but I just bought a microphone wire from radioshack. Not sure what size it is, but it is shielded. Ended up selling the car before having to do it. Didn't seem very fun with my little knowledge

[ericem]

With my car I noticed it was very very brittle and broken up, so what I did was use high tempt RTV and coated it along the wire outside in the engine bay as far as necessary and so far got my car running and it runs awesome! No dropping octane factor problems (chipless though keep in mind). Car is running great though stock I am plenty satisfied.

[kleinkid]

When I repaired mine, I believe I got the wire fro Radio Shack also. Can't remember what it was though.

[Mattheww044]

Ya I think mine just said X' Shielded Microphone Cord (X' being the length)

[NuclearBacon]

ok, so shoot me into the ocean if this is wrong... But i didnt have sheilded wire when i wired the knock sensor on my gl-10... so i took a little bit of the shielded wire, and stripped the outer coating off.. so i had the shield in my hand (like braided wire around another wire) and i pulled enough off where i could twist it in my fingers and connect it to another wire... i then ran this shielded-connected wire to ground. ran the signal wire to the knock sensor... raced with it for 3 years, never had a CEL again hehe

[mike-tracy]

ok, so shoot me into the ocean if this is wrong... But i didnt have sheilded wire when i wired the knock sensor on my gl-10... so i took a little bit of the shielded wire, and stripped the outer coating off.. so i had the shield in my hand (like braided wire around another wire) and i pulled enough off where i could twist it in my fingers and connect it to another wire... i then ran this shielded-connected wire to ground. ran the signal wire to the knock sensor... raced with it for 3 years, never had a CEL again hehe

I had that same idea the other day, since I couldn't find any intact 90-94 legacy knock sensor wires. I'll have to try it since yours worked out.

[Legacy777]

It would be best if you can get a shielded cable, but if you can't, I don't think it's going to be the end of the world.

Microphone cable probably would work out good.

[BSOD2600]

Microphone cable won't break down quickly being in the hot engine bay?

[Legacy777]

Not sure.....

[Mattheww044]

yea, I never had time to get in installed before I sold it. That is the only thing I could find that would be "shielded wire" though.

[n2x4]

I'm running mono microphone cable from radioshack on my car. No problems.

[BSOD2600]

Well finally got all the parts and a day off from work to tackle the project. After taking off the TMIC, I was dismayed to find a decent amount of oil in the tubes. I assume this means the TD05 is on the way out?


I wanted to feed the microphone wire through the passenger side hole with main engine harness.. .but after looking things over, I wouldn't have been able to access in the cabin without removing the dash . Ended up feeding it through the driver side hole which the speedometer cable uses (and the LC1 and boost line -- guh it's getting full). Double checked the existing KS lines to the ECU on B127 and then cut them off, leaving ~2" sticking out. Soldered the wires together, covered with heatshrink and then electrical tape.

Once I figured out how to release the KS pin from the plastic, I quicly soldered the wires to it.

Figured that might as well use both of the wires in the core, in case one breaks or something over time. Also covered the wire back to the firewall with automotive plastic tubing.

Anyways, after getting everything back together, fired up the car to make sure everything still worked and no CEL. Tomorrow comes the real test to see if a new knock sensor and wiring back to the ECU has fixed my ongoing knocking issues. If not, then only thing else is real mechanical knocking, some how caused by the wreck this summer... in which case, I'm done with this car.

[BSOD2600]

Well with more data logging on some highway driving, the knock retardation has went from weird to worse. Now *every* time I'm on boost, the knock retardation parameter raises quickly to 15 and says there (if I stay WOT long enough). Then it slowly decreases once I'm off boost. It changes so slowly that I can actually watch the parameter count down (while driving) on the laptop. I'll post the logs in a bit.

What now?

[BSOD2600]

Here is a sample of the logs, with how ridiculous the knock retardation is now. I'm fairly sure this was a highway 5th gear WOT.

Code: Select all

LogEntrySeconds	KnockRetard(BTDC	OctaneFactor(%)	MAP(PSI)	WB(AFR)				
430.42	0	0.00	-4.48	15.47				
430.66	0	0.00	-4.03	14.45				
430.91	0	0.00	-2.52	14.93				
431.15	0	0.00	0.35	13.97				
431.41	0	0.00	1.26	14.41				
431.64	0	0.00	3.98	13.78				
431.89	0	0.00	5.94	14.57				
432.13	0	0.00	7.15	11.89				
432.38	1	0.00	9.42	11.91				
432.63	2	0.00	8.81	11.84				
432.87	2	0.00	8.96	11.42				
433.12	4	0.00	8.96	11.67				
433.36	6	0.00	9.42	11.49				
433.61	6	0.00	10.02	11.87				
433.85	6	0.00	9.27	11.49				
434.10	10	0.00	9.57	11.34				
434.35	10	0.00	9.87	11.58				
434.59	12	0.00	10.17	11.46				
434.84	13	0.00	9.87	11.75				
435.09	13	0.00	10.02	12.08				
435.34	13	0.00	9.42	11.38				
435.58	14	0.00	10.02	11.42				
435.82	15	0.00	9.27	11.63				
436.07	15	0.00	9.87	11.75				
436.31	15	0.00	10.17	11.41				
436.56	15	0.00	9.42	11.44				
436.81	15	0.00	-7.66	11.35				
437.05	15	0.00	-9.17	12.86				
437.30	15	0.00	-9.47	13.80				
437.54	15	0.00	-9.62	51.01				
437.80	14	0.00	-9.77	0.00				
438.04	14	0.00	-9.77	0.00				
438.29	14	0.00	-10.07	0.00				
438.53	14	0.00	-10.38	0.00				
438.77	14	0.00	-10.68	0.00				
439.02	13	0.00	-10.83	0.00				
439.26	13	0.00	-10.98	0.00				
439.51	13	0.00	-11.13	0.00				
439.75	13	0.00	-11.13	0.00				
440.00	12	0.00	-11.28	0.00				
440.25	12	0.00	-11.28	0.00				
440.49	12	0.00	-11.28	0.00				
440.74	12	0.00	-11.43	0.00				
440.99	11	0.00	-11.43	0.00				
441.23	11	0.00	-11.59	0.00				
441.48	11	0.00	-11.59	0.00				
441.72	11	0.00	-11.74	0.00				
441.97	10	0.00	-11.74	0.00				
442.21	10	0.00	-11.89	0.00				
442.46	10	0.00	-11.74	0.00				
442.71	10	0.00	-11.74	0.00				
442.95	9	0.00	-11.13	0.00				
443.20	9	0.00	-10.83	0.00				
443.44	9	0.00	-9.77	40.07				
443.69	9	0.00	-7.81	20.50				
443.94	9	0.00	-7.36	14.47				
444.18	8	0.00	-7.36	12.97				
444.43	8	0.00	-7.20	13.56				
444.67	8	0.00	-6.75	15.30				
444.92	8	0.00	-5.39	14.66				
445.17	7	0.00	-5.24	13.89				
445.41	7	0.00	-5.09	15.33				
445.66	7	0.00	-4.94	13.38				
445.91	7	0.00	-4.79	14.62				
446.15	6	0.00	-5.09	15.64				
446.39	6	0.00	-4.94	13.45				
446.64	6	0.00	-5.09	14.68				
446.89	6	0.00	-5.39	14.85				
447.13	5	0.00	-5.54	13.76				
447.38	5	0.00	-5.69	13.97				
447.63	5	0.00	-6.00	14.64				
447.87	5	0.00	-5.69	14.68				
448.12	4	0.00	-5.24	14.45				
448.36	4	0.00	-4.94	15.40				
448.61	4	0.00	-4.48	14.90				
448.85	4	0.00	-4.03	14.37				
449.10	4	0.00	-4.48	14.07				
449.35	3	0.00	-5.24	14.76				
449.60	3	0.00	-5.39	13.59				
449.84	3	0.00	-5.39	13.61				
450.08	3	0.00	-5.39	14.41				
450.33	2	0.00	-5.24	13.61				
450.58	2	0.00	-5.24	14.14				
450.82	2	0.00	-5.39	14.35				
451.07	2	0.00	-5.54	15.04				
451.31	1	0.00	-5.54	15.10				
451.56	1	0.00	-5.54	13.34				
451.81	1	0.00	-5.69	13.90				
452.05	1	0.00	-5.69	14.93				
452.30	0	0.00	-5.69	13.78				
452.54	0	0.00	-5.69	14.73				
452.79	0	0.00	-6.00	14.35				
453.03	0	0.00	-6.30	14.02				
453.29	0	0.00	-6.60	13.93				
453.53	0	0.00	-6.75	14.38				
453.77	0	0.00	-6.75	14.44