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bwcress

Need help diagnosing an issue

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So i recently swapped chasis and everything was perfect up until maybe 3 days ago... car starts and idles fine but when free revved(in neutral) it makes boost as if im doing a higway pull. i have checked basically every sensor on the car and have no idea on what to do next any help would be greatly appreciated. car is a 90x8 with a non-vvti 1jz stock computer with safc and bcc.

 

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i figured it would be hard to believe so i made a vid of the issue... in the begining of the vid im showing the timing marks its kinda hard to see the crank mark but its spot on

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in the video it shows the timing marks and that they are spot on... maybe something is fucking with the ignition timing?

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Two Ideas I am pulling out of my ass:

wastegate? Restriction in the exhaust?

boost is made under load. whats putting it under load?

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Yea the marks on the cam gears and the the crank pulley line up perfect... and when you say cas im assuming you are talking about talking about the cam sensor plugs? If so no they are in good condition and the resistance for the sensors themselves are within spec

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I think Mark was referring to the crank angle sensor

 

I saw you were asking for a spare jzz30 ecu, i think I have one somewhere in my garage, ill dig through it tomorrow and see what I find.

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Ive changed the ecu already no change... is it possible that something mechanically wrong with the head could cause this?

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Reluctor ring?

 

The gfs 1j was off a tooth, car would start/idle/drive/boost great until 3000rpms and fall flat on it's face popping, and also built boost in neutral. If you're sure timing is right maybe the reluctor ring is loose

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I pulled it apart yesterday to check the reluctor ring it was dead on and not loose at all

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Have you had the timing belt apart since the car run last ? I have seen where the timing rotor on the crank pulley come lose and also when it was reinstalled backwards and runs like shit but appears to be timed right . Attach a timing light with advance dial to the number one cylinder turn the dial to get the crank pulley lined up with the 0 degree mark now if you point the light at each cam gear they should be lined up with there mark . If they are not there is big trouble in little Tokyo and I would check the condition of the timing rotor on the crank pulley . Also check the grounds on the engine harness including E2 which should only have continuity with ground when the ecu is completely plugged in . Good luck !

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Also check the shielded wires of all the timing related components for shorts to ground and to one another and that the shielding is grounded . Good luck !

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I had the timing belt off yesterday the reluctor ring has not moved i even took the timing belt cog off to make sure and it was perfect

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thanks for the update travis... yup that was it so problem was solved with a set of usdm 2j cams and gears

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took the car to a drift event ran flawless all day... pics and vids will be in build thread soon

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diy adjustable cam gears bro. super legit

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Someone was making 4AGE cam gears for a while that were "adjustable" the almost remind me of this. They had a few extra knock-pin grooves machined in them so you could put them on a few different directions yielding a couple degrees of timing give or take.

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