Nissan rb25 drops a cylinder at 4k rpm. Solved

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jompa_a
Helpful MS/Extra'er
Posts: 77
Joined: Sat Jul 14, 2012 4:46 am

Nissan rb25 drops a cylinder at 4k rpm. Solved

Post by jompa_a »

I helping tuning a Skyline with an rb25 and 4000rpm and about 0,4 bar boost it just drops a cylinder, it can be two. Hard to hear, but its not random missfires.
I gaped the new plugs, increased the dwell a bit, lean it out to about 0,80 lambda (started out at 0,75 ish). Oh, and its on E85.
Still the same. I trigger logged as well. Nothing funny going on with the trigger.
Its a 36-1 with VR. No cam sync.
Wasted spark with six drivers added.

And I just realized I left the laptop at the car...
I have a bit older msq on this computer that matches it except for the ve and ignition tables.

Am I missing something or can I tune it out. It feels like its a hardware issue.
Last edited by jompa_a on Tue Jun 27, 2017 11:43 am, edited 2 times in total.
Greetings from Sweden /Jonas
jompa_a
Helpful MS/Extra'er
Posts: 77
Joined: Sat Jul 14, 2012 4:46 am

Re: Nissan rb25 drops a cylinder at 4k rpm.

Post by jompa_a »

I increased the dwell to 2,8ms from 2,5ms
Greetings from Sweden /Jonas
jompa_a
Helpful MS/Extra'er
Posts: 77
Joined: Sat Jul 14, 2012 4:46 am

Re: Nissan rb25 drops a cylinder at 4k rpm.

Post by jompa_a »

Problem solved.

The fuelrail lifted under boost.
Greetings from Sweden /Jonas
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