1JZ throttle loss

Joined
Oct 2, 2018
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#1
Hi guys,

so, I recently bought a 1990 JZA70. Runs great until the engine has been heating up for about 20 minutes, driving on the freeway. Then if I give it much throttle at all, it acts like its hit the rev limit, at about 3-4k rpm. I have to let off the gas in order to get any sort of acceleration to shift to the next gear. Let the car sit, and its fine once it cools back down. I don't even know where to start, especially since the problem only pops up after the engine is hot. There's has an exhaust leak on the uppipe, but that's the only engine related issue that I know of so far.
 

tylerjacobsen85

WVsupradriver
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Nov 28, 2005
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#2
It could be unburnt fuel popping in the hot exhaust. I would check/change your spark plugs first. But be careful with the coil pack connectors they will shatter like glass If your not careful. If you do break them you can buy just the connectors from toyota and other places online.
 

twin2turbo

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Apr 1, 2010
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Mill Creek, Wa
#4
As mentioned check for cracks in the each coil pack along the stems. Also you may have blown capacitors within the ECU, this can cause all sorts of strange issues. If its bad enough the acid can eat through the circuit board rendering it unfixable.

Id also check for codes

Look into a knock sensor rewire aswell. The shielding on the original wiring will be heat damaged and worn out. You can rewire them with RG-58 stranded coax cable that you can find any most wiring stores.


Just a few things to check