whats causing the knock?

[dan2288]

I have my stock boost guage turned into a knock sum guage and I noticed Im getting knock in the higher rpms. It wasnt like this before, It just started not that long ago. Im running a 16g at 20psi. I have my fuel pressure at 43.5 with the vac line off. I just changed my fuel filter yesterday and put on msd wires and ngk plugs gapped at .026. What else should I check?

 

[donniekak]

Turn the boost down to wategate level, to make sure it's not just the engine making noise.

 

[okm12346]

Whats the AFR when you get knock? At WOT it should be reading 10.5

 

[dan2288]

not sure, my wideband isnt on right now. But my chip is set for 11.0 so Im sure its around there.

 

[JusMX141]

Check the knock sensor itself, and replace it if the rubber insulation feels gooey at all.

If you would've seen how poor the stock knock sensor was on my '92 FWD when I got the car, you would've died laughing. The goo was COMPLETELY out of the sensor, and had run down the entire back of the block behind the A/C compressor. I'm just now scraping the gooey mess off the block as the engine is removed for rebuild.

No wonder the knock counts would max out anytime I got on the throttle when I first got this beast. What's funny is there were a TON of receipts in the glove box where the previous owner had taken the car to the dealer for "poor performance in third gear". They changed everything from the plugs to the fuel filter, even the ECU and the problem was the knock sensor the entire time. Just goes to show you that even a Mitsubishi dealer has no idea how to work on their own f*cking cars.

Oh well, at least I got a brand new EPROM ECU out of the deal- it came directly from the dealer, and was in the car for 800 miles before I took ownership.

 

[zhjiln]

turn down boost...

 

[dan2288]

I will take a look at the knock sensor tomm. And I had no problem running this amount of boost earlier.