Hard to Explain Behavior
02-06-2020, 08:45 PM
#16
Team Owner
best plugs to use are Bosch PN 7900 at autozone
02-07-2020, 02:53 AM
#17
Rennlist Member
Hey Guys,
i unplugged both knock sensors and hall sensor once at a time. There was no change in the idle. Is it strange for all to go at once? Is there a relay that controls these? The sensors look new. I haven’t done an intake refresh but the PO May have because they really look new.
i unplugged both knock sensors and hall sensor once at a time. There was no change in the idle. Is it strange for all to go at once? Is there a relay that controls these? The sensors look new. I haven’t done an intake refresh but the PO May have because they really look new.
Ash,
Not sure you have grasped the concept here- the test only requires the removal of one of the plugs. That you are expecting to see a difference in idle is suspect and most probably, a false perception. Changing the advance at idle makes little noticeable difference in my Shark Tuning experience albeit it seemed to me that advancing the idle timing a few degrees produced a more even response so I suppose one might just be able to notice something but it is not what I had in mind. The idea of the test I suggested is to remove a plug from one of the three sensors to test whether under dynamic conditions you notice a degree of downgraded performance. I had no problem detecting the difference in mid range to top end performance when I did this. If the sensors are OK you should notice this degradation, if one of the sensors is down you will not detect any difference other than a placebo effect [heaven forbid]..
You also have some other suggestions to work with - hopefully process of elimination will get you to the winning post!
02-07-2020, 03:12 AM
#18
Chronic Tool Dropper
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Disconnecting any of the three sensors won't change the idle. It -should- reduce ignition advance, which affects power delivery. Did the power fall off with any sensor disconnected? If not, you likely have a sensor problem.
02-07-2020, 04:31 AM
#20
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Ash,
Not sure you have grasped the concept here- the test only requires the removal of one of the plugs. That you are expecting to see a difference in idle is suspect and most probably, a false perception. Changing the advance at idle makes little noticeable difference in my Shark Tuning experience albeit it seemed to me that advancing the idle timing a few degrees produced a more even response so I suppose one might just be able to notice something but it is not what I had in mind. The idea of the test I suggested is to remove a plug from one of the three sensors to test whether under dynamic conditions you notice a degree of downgraded performance. I had no problem detecting the difference in mid range to top end performance when I did this. If the sensors are OK you should notice this degradation, if one of the sensors is down you will not detect any difference other than a placebo effect [heaven forbid]..
You also have some other suggestions to work with - hopefully process of elimination will get you to the winning post!
Ash,
Not sure you have grasped the concept here- the test only requires the removal of one of the plugs. That you are expecting to see a difference in idle is suspect and most probably, a false perception. Changing the advance at idle makes little noticeable difference in my Shark Tuning experience albeit it seemed to me that advancing the idle timing a few degrees produced a more even response so I suppose one might just be able to notice something but it is not what I had in mind. The idea of the test I suggested is to remove a plug from one of the three sensors to test whether under dynamic conditions you notice a degree of downgraded performance. I had no problem detecting the difference in mid range to top end performance when I did this. If the sensors are OK you should notice this degradation, if one of the sensors is down you will not detect any difference other than a placebo effect [heaven forbid]..
You also have some other suggestions to work with - hopefully process of elimination will get you to the winning post!
you’re right. I wasn’t tracking. I thought unplugging one sensor at a time would have a direct impact on idle smoothness. I think I’ll check the spark plugs. The sensors look brand new. The PO did a lot of things to the car. I’m not saying he did them well but it’s hard to mess up installing a knock or hall sensor. I’ll report back after the plugs have been changed.
02-07-2020, 05:06 PM
#23
In your owners manual it should have the Bosch part number and gap, which is probably discontinued and superseded by another Bosch. I think the part number to request might be WR7DC or the newer WR7DC+. Others can confirm, but I believe that is it.
02-07-2020, 05:46 PM
#24
Team Owner
That's a good part number amazon sells them silver tips 1.99 each
02-07-2020, 06:21 PM
#25
Just to try to add clarity:
Bosch 7900 WR7DC+ Super Spark Plug
SKU: #WR7DC+
ITEM : # BOS7900
BRAND : Bosch
https://www.boschsparkplugs.net/product.aspx?zpid=8149
Bosch 7900 WR7DC+ Super Spark Plug
SKU: #WR7DC+
ITEM : # BOS7900
BRAND : Bosch
https://www.boschsparkplugs.net/product.aspx?zpid=8149
02-07-2020, 09:21 PM
#26
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Which model of NGK plugs do you currently have? I have never used NGK but someone here may have experience with the ones that you have and be able to give you their first hand review, they might be a suitable issue free substitute for the Bosch.
In your owners manual it should have the Bosch part number and gap, which is probably discontinued and superseded by another Bosch. I think the part number to request might be WR7DC or the newer WR7DC+. Others can confirm, but I believe that is it.
In your owners manual it should have the Bosch part number and gap, which is probably discontinued and superseded by another Bosch. I think the part number to request might be WR7DC or the newer WR7DC+. Others can confirm, but I believe that is it.
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Shark2626 (02-07-2020)
02-08-2020, 03:27 PM
#27
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Update - I changed the plugs and now she’s running much better. The NGKs I removed were not fouled or anything, maybe the gap was off on a couple.
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Shark2626 (02-08-2020)
02-09-2020, 05:55 AM
#30
Rennlist Member
A problem with a knock sensor or the Hall sensor will make no difference at idle. That's because the 6deg retard is only activated at higher engine loads and rpm. (To prevent knock)
Unplug the front knock sensor, then drive the car through the rpm and load range and see if it is different or the same. If the same the knock 6deg retard is being activated because of a faulty sensor.
Unplug the front knock sensor, then drive the car through the rpm and load range and see if it is different or the same. If the same the knock 6deg retard is being activated because of a faulty sensor.