Engine Cut out at 5200 rpm 3rd Gear GTs-t RB20DET '92

[Sky_kid]

My problem is as follows:
Under WOT in 3rd gear (4th too) when the RPM hits about 5200 RPM the engine stops making power.
It doesn't stall.
In 1st or 2nd gear it seems fine, pulls great.

There maybe some detonation as there is a slight rattle under WOT.
I was running 14 psi RB20DET. Timing isn't terribly advanced say 25-27 deg BTDC.
I've since dialed back the boost a few ticks and ran some sea foam through the engine.
The engine runs a bit smoother now.

Fuel pressure should be fine, just got a new fuel pump and it fixed fuel pressure when I got it dynoed last summer.

I am thinking Air leaks. Would a blocked PVC cause this?

[BrianV8]

stock turbo probably running out of flow. My old rb20 with stock turbo after 5200 use to roll back to around 11psi on the top end

[magular]

my stock rb20 only pulls really hard starting around 5-6500... i have it set at 12 psi. apparently when a 15 it will blow the turbo. so 12 seems ok. does the trick. reaches full boost around 4. but takes a second to really pull ( like i said, around 5 pulls more then anywhere else in the rpm gauge )

so not sure if this helps, just telling you how mine works is all.

ive had some cut out before as well though, but it was caused due to miss firing. my coils were dirty as well as my coil harness. i changed both and now smooth all through the gears.

so maybe its something electronic. my buddys wrx use to do that. like spitting and not really climbing past 4800. was just a short throwing the ecu into safety mode.

hope you get to fix the problem! gotta keep our skylines running.

[rak123]

Check your coil packs with a multi meter if they're over 0.8 ohm replace them and your spark plugs

[Voodoo_ChildR32]

Any of the afore mentioned things, or you've reached the top of your useable powerband and are just over revving your engine. Also try cleaning and resoldering your MAF, gap plugs to 0.8mm.


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[motoking332]

like the last 2 gentlemen stated start with your plugs and go from there, i had a similar problem, i just changed plugs and i was good to go

[s13shearer]

I had a similar issue with my car last week 1st and 2nd were ok, and 3rd 4th 5th at 4500 it would hesitate/break up. I just got the car and was going to do a tune up. Oil and filter, plugs and the coils are like new, fuel filter figured that might help. Had similar issues in my rb20 240sx and it was a fuel issue (clogged sock on the pump and very plugged filter) I have done the tune up this weekend but before I did last week. I was working on it and found the rear knock sensor plug dangling with 1/2 the sensor broke off. Needless to say I slapped a spare that I had In the shed on it and it fixed the issue i was having. No check engine light came on either

[motoking332]

touche good sir