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Knock sensor testing

812 views 1 reply 1 participant last post by  Kanookstr 
#1 ·
Is there a way of testing the knock sensor on a 1999 502 Mag MPI with the MEFI3 ECU without using a scanning tool????

I noticed a ping, Kinda like an Octane/detonation ping, on the starboard side of my motor only at cruising speed of around 3500 RPM.
It's not there below 3500 rpm.

It's not the gas. and when the pinging started it was like turning on a switch. I noticed it right away.....Fuel pressure was fine, EGT temps where fine, ????Motor is running and pulling as strong as it usually does.

Can I just unplug the Knock sensor, and it would put it in safe mode????? This way I can try running up to the 3500 rpms and see if it still pings??? or unplugging the knock sensor doesn't work that way????

Thanks
 
#2 ·
OK, Jumped in the boat this morning to look for a lose wire and check the plugs.
No lose wires, and all plugs looked great.?????
As I was putting in the last plug, my shirt sleeve got caught on the dip stick..... when I yanked it free......
PING<<>>TANG>><<PING.... went the dip stick TUBE!!!!
WHAT was that I thought????? I started shaking the tube and sure enough it sounded a Lot like that pinging I heard. So I followed the tube down to where the holder was, and sure enough it had a real shiny spot where it rapped around the tube.
I then started thinking how weird it was that the engine only pinged on the starboard side, and at exactly 3500 rpm. it didn't do it at 3700+ rpm, nor did it do it at a lower RPM. it also only did it when I was at that rpm cruising, not on acceleration like normal detonation would ac-cure...
Lets just hope it was that.??? going for a test run this afternoon.
I'll let you guys know.
 
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