Yesterday I finally go back to my wife's J. We set the knock sensor in place at the grounding point on the driver's side of the engine, got an ohm reading of 558, and secured it. Then we attached the wiring harness and got a reading of 557. Figurng we were good to go, we connected it to the ECU.
It ran well for about 10 minutes, then it ran like crap. We relocated the ks to a spot that requires a longer bolt. We took the readings again, (same) and road tested it. It ran worse than before. Like I said It's the last straw. (please remind me to order more straws)
I have replaced the ks with the resistor, and it runs fine. I'd rather use the ks and harness because I have about $100 tied up in parts.
Any other suggestions from the oracles out there?
That's the last straw!
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gr8scott72
- Posts: 1220
- Joined: Thu Feb 16, 2006 1:37 pm
- Car: 1994 Infiniti J30t
Re: That's the last straw! (mej30guy)
Ebay the parts and just keep the resistor on there but make sure to always use premium fuel.
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yodawill2000
- Posts: 3888
- Joined: Thu Mar 24, 2005 4:10 pm
- Car: 94 Infiniti J30
- Location: Grand Prairie TEXAS
Re: (yodawill2000)
It would be interesting to know how the resistance reading has changed, after the engine and KS have warmed up.
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coolyun_98
- Posts: 313
- Joined: Fri Mar 09, 2007 8:29 pm
- Car: 1993 J30 11,7000kM
Re: (GerryO)
From my understanding, the "knock" signal is detected and DIGITALLY FILTERED (for certain time-frequency, depending on engine speed) by the ECU. If ur car did not operate properly after waming up, the KS MUST pick up SOME engine noise that has the SAME time-frequecy as a KNOCK.
All i can think is that the KS picks up some noise related to engine harmonics. TRY to locate the KS as close to the block as possible as that is the only place to precisely detect a knock.
All i can think is that the KS picks up some noise related to engine harmonics. TRY to locate the KS as close to the block as possible as that is the only place to precisely detect a knock.
Re: (coolyun_98)
Expanding on what coolyun_98 has stated, the possibilities would seem to be:coolyun_98 wrote:From my understanding, the "knock" signal is detected and DIGITALLY FILTERED (for certain time-frequency, depending on engine speed) by the ECU. If ur car did not operate properly after waming up, the KS MUST pick up SOME engine noise that has the SAME time-frequecy as a KNOCK.
All i can think is that the KS picks up some noise related to engine harmonics. TRY to locate the KS as close to the block as possible as that is the only place to precisely detect a knock.
- "excessive" vibrations detected either due to the real conditions (knocking) or the new mounting location
- low background/normal vibration signal strength due to the new mounting location, telling the ECM that the KS isn't working
- a temperature dependent direct short to ground or loss of ground connection = a bad KS, sub-harness or conductive anti-seize contaminated or open electrical connections
Re: (yodawill2000)
If you look at the engine picture posted by gangstar concerning a timing belt, I first located the ks at the grounding point where the black wire comes out from under the engine cover, driver's side. It is to the right of the hole where the lone hex bolt secures the cover. I moved that wire to another location so that the ks sat right on the block. No good.
The other spot was at the back of the engine, same side, where the crossover tubes are bolted to the engine. This is an 8x100mm bolt that sits deeper in the engine so I thought it would perform better. Again, nothing.
I do have a slight leak in the passenger side manifold, like air escaping. I described the noise to the guy at the muffler shop, and he said it sounds more like a bad gasket or loose bolt. If it sounded like a lawnmower, then a major problem.
Could this be the vibration that the ks is picking up? Also, I've noticed that even after a 10 minute test drive, the engine block is very hot. Maybe that has an effect.
Just something for you guys to think about. Thanks.
The other spot was at the back of the engine, same side, where the crossover tubes are bolted to the engine. This is an 8x100mm bolt that sits deeper in the engine so I thought it would perform better. Again, nothing.
I do have a slight leak in the passenger side manifold, like air escaping. I described the noise to the guy at the muffler shop, and he said it sounds more like a bad gasket or loose bolt. If it sounded like a lawnmower, then a major problem.
Could this be the vibration that the ks is picking up? Also, I've noticed that even after a 10 minute test drive, the engine block is very hot. Maybe that has an effect.
Just something for you guys to think about. Thanks.
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gr8scott72
- Posts: 1220
- Joined: Thu Feb 16, 2006 1:37 pm
- Car: 1994 Infiniti J30t
Re: (mej30guy)
The leaky manifold will also cause the J to not run good. It's not as bad as the knock sensor not working but after I got the manifold leak fixed in my 93, it was like having a new car. It was quiet AND more powerful.mej30guy wrote:If you look at the engine picture posted by gangstar concerning a timing belt, I first located the ks at the grounding point where the black wire comes out from under the engine cover, driver's side. It is to the right of the hole where the lone hex bolt secures the cover. I moved that wire to another location so that the ks sat right on the block. No good.
The other spot was at the back of the engine, same side, where the crossover tubes are bolted to the engine. This is an 8x100mm bolt that sits deeper in the engine so I thought it would perform better. Again, nothing.
I do have a slight leak in the passenger side manifold, like air escaping. I described the noise to the guy at the muffler shop, and he said it sounds more like a bad gasket or loose bolt. If it sounded like a lawnmower, then a major problem.
Could this be the vibration that the ks is picking up? Also, I've noticed that even after a 10 minute test drive, the engine block is very hot. Maybe that has an effect.
Just something for you guys to think about. Thanks.
Re: (gr8scott72)
I know. That's why it's only used around town for the time being, because I don't want to make the manifold problem any worse. But it ran terrible before the leak. (which I expect I got when I was running the engine around 85mph on a 45 minute trip to flush out the carbon)
Re: (mej30guy)
The engine block is located under the plenum and the intake manifold, and under the valve covers and the heads. It still cannot be seen in any of the photos in this link.mej30guy wrote:
Could this be the vibration that the ks is picking up? Also, I've noticed that even after a 10 minute test drive, the engine block is very hot. Maybe that has an effect.
Just something for you guys to think about. Thanks.
zerothread/337631
I wonder if using the E-mance diagnostic would yield any more clues about what's going on with your KS?
Re: (GerryO)
First of all, let me say that your engine is cleaner than my bathroom!!! Outstanding effort.
So obviously I don't have the ks in the right place. It should not be on top of the engine, it should be under the plenum, on the side somewhere? Most of the threads advocate relocating it on top of the engine, with great success. So that's what I'm trying to do. I can't imagine that if the ks is putting out an ohm reading, that it isn't registering with the ECU.
So obviously I don't have the ks in the right place. It should not be on top of the engine, it should be under the plenum, on the side somewhere? Most of the threads advocate relocating it on top of the engine, with great success. So that's what I'm trying to do. I can't imagine that if the ks is putting out an ohm reading, that it isn't registering with the ECU.