Goudgey11 15 Posted December 23, 2014 Report Share Posted December 23, 2014 Hi all !! My 1997 sc vr6 is hesitating form 4000 to 5500 then takes of like a rocket till limiter,keep getting both knock sensors low signal fault codes coming up on vag com,replaced the one on the front of the engine,checked the wiring,but still getting both of the sensors reporting low signal.any help would be really appreciated,thanks for your time. Link to post Share on other sites
Bealieboy 1,625 Posted December 23, 2014 Report Share Posted December 23, 2014 Did you replace with a new oem sensor? Sometimes the lesser manufacturers products cause more faults than they fix. Have you tried unplugging the maf and running the car? I heard these throw some random codes when they go wrong. Sent from my iPhone using Tapatalk Link to post Share on other sites
Goudgey11 15 Posted December 24, 2014 Author Report Share Posted December 24, 2014 Hi thanks for your reply,yeh all Oem parts,even replaced the maf,I'm thinking posable ecu .thanks again have a good x mas Bealieboy 1 Link to post Share on other sites
c00k 435 Posted December 25, 2014 Report Share Posted December 25, 2014 What other stuff are you running along side the SC? As knock sensor fault usally come from the engine running to hot , causing it to have spark knock. Are you running normal compression? This is quite a common issue with force induction and standard compression. Also I would run atleast a 16row oil cooler. Low temp thermostat. New rad, check water pump and replace if needed. All to help lower engine temp. Best thing to do is run a de-compression plate. To correct compression with the SC. Water and methanol can also work very well , as it can greatly reduce intake temperature. Cover the underside of intake manifold ZircoFlex 3 coating. Meant to reduce surface temperature by up to 85%. D11PS 1 Link to post Share on other sites
c00k 435 Posted December 25, 2014 Report Share Posted December 25, 2014 Little bit of info on spark knock http://www.onestopauto.com/What-causes-spark-knock.html Link to post Share on other sites
Goudgey11 15 Posted December 26, 2014 Author Report Share Posted December 26, 2014 Hi thanks for your advice,running a entry level 6psi pulley,giac chip,custom short runner intake,mk4 head gasket,apr bolts,6branch manifold,fitted a new water pump,but didn't think about the temp readings will check that,do you think a faulty injector would cause this,getting a slight misfire count on vag com,but fitted all new ignition parts.thanks again for your help. Link to post Share on other sites
Sump_slammer 23 Posted December 29, 2014 Report Share Posted December 29, 2014 Check all your earths are good. Main earths to engine by the gearbox and the small earth near the throttle body. A poor earth can cause low voltage faults as resistance goes up volts comes down. Also take the knock sensors off and make sure the block face is clean no paint just shinney metal give it a good sand with a sanding block. Also make sure theres oil in it. Low oil level will cause the engine to knock. Theres 3 wires going to a knock sensor, live, earth and a signal. Check to make sure your getting a good feed and earth then check the sensors are working by probing into the signal wire usually the middle pin and with a multi metre set to volts dc black lead on earth and red wire of multi metre to signal wire. Turn the ignition on and tap the sensor (whilst still bolted to block) with a spanner somthing like a 19mm with a bit of weight behind it you should see a slight reading on the multi metre. Link to post Share on other sites
Sump_slammer 23 Posted December 29, 2014 Report Share Posted December 29, 2014 Note when testing the sensors signal wire it needs to be pluged in. Otherwise it wont do owt. Link to post Share on other sites
Goudgey11 15 Posted December 30, 2014 Author Report Share Posted December 30, 2014 Hi thanks a lot for your info,thank you for your time will investigate further,will post my findings or fixed solution,may help others Link to post Share on other sites
Goudgey11 15 Posted January 1, 2015 Author Report Share Posted January 1, 2015 Thanks for the ones who replied,carried out all the testing you advised,no joy unfortunately,sent ecu away to be tested ,turns out to be faulty thanks again Sump_slammer and richierich37 2 Link to post Share on other sites
vr6turbo 27 Posted January 3, 2015 Report Share Posted January 3, 2015 running a mk4 gasket will increase you compression ratiohave you taken this into account Link to post Share on other sites
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