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Raceready68

Knocking 1jz

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I was dynoing my car at work when the front knock senor went. Its been a little suspect for a while so I am not shocked it went. So I had it changed and the knock code is gone.

 

How ever my car is showing knock on boost on the SAFC 2 and cutting power big time so it is knocking for sure. I figured it was a bad tank of gas which is not uncommon out here. So today I filled the car with a fresh tank of 94 its slightly better but still knocking.

 

I am thinking maybe my fuel filter plugged , fuel pump is on its way out , or injectors are fucked, the other thing I am thinking is maybe the caps started leaking in the ecu.

 

Car drives normal as long as its out of boost. Motors still strong no blow bye.

 

 

I did seafoam the car before I changed the oil and plugs. Which was done before dynoing.

 

Is there anything I am over looking or should be checking ?

 

I think my next step is to check my fuel pressure and hook up my wide band.

 

Any sugestions ?

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what coil plugs do u have? the stock ones are crap.

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The first thing I would do is put in your wideband and see what the AFRs are doing. I'm assuming you haven't been messing around with the AFC without a wideband to see what effect it's having. When did you last change your fuel filter? if you can't remember or the answer is never... change it. What are your plugs gapped to and what injectors are you running? When was the last time you took a look at your coilpacks for cracking in the body of them?

 

If your general AFRs are too lean it's a widespread fueling issue, if the overall AFRs look good and it's still knocking it's probably a localized issue on one cylinder like a bad injector or weak coilpack.

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Stock injectors. SAFC2 is set stock I was just setting the car up to baseline it. Plugs gaped to .025, Coil packs had some cracks but not any where important so I siliconed them over the cracks just incase.

 

Fuel filter will be ordered tomorrow I am guessing the jzx81 fuel filters the same as the Cressida I am also guessing its in a spot that really sucks to get to.

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I should mention the wideband on the dyno said it was fairly lean but I am not sure how the check engine light and fucked knock sensor would affect that. Car was running like a total bag of shit on the dyno just braking up. I think I need to recheck it with the wideband now that the knock sensor codes gone.

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I swear I could write a fucking book on the subject. Short answer is always fix the tune.

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