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Help! Car Dying Around 3500Rpm (Rb20)

cabramatta
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cabramatta Community Regular

cabramatta

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Hey guys

Just put a RB20DET into my S13, took it for a test drive for the first time.

The car drives and idles fine, but as soon as I put my foot down in any gear (or even slowly go higher in RPM) the car jerks at around 3500RPM like it's not getting fuel and just jerks forward and back and misfires alot.

I haven't connected my VSS yet (speed sensor from the gearbox for speedo to work) but I'm guessing this wouldn't have anything to do with it (unless someone can prove me wrong which I'm totally fine with!).

The following are all new:

Spark plugs

Oil

Oil Filter

Fuel bump (bosch 040 or whatever it is)

Fuel filter

I've read that the car will go into limp mode with a faulty MAF (airflow meter sensor/air flow meter) or the TPS, but I would have thought that if the car was going into LIMP then it would idle rough aswell.. However, the car idles fine and drives fine, just at that RPM it just dies and doesn't go anymore. Like a fuel cut ?

I'm all out of ideas but I've read that the VSS could also be the culprit but I really don't see how that would be possible ?

It's an RB20DET out of a GTS-T R32.

Turbo is a standard turbo from RB25, justjap frontdump pipe, de-cat and 3" piping to rear.

Any help will be greatly appreciated.

Thanks in advance

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  • 2 weeks later...
cabramatta Community Regular

cabramatta

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I ended up pulling the coils out and applying sillicone on them from one of the DIY threads on here.

Let it set for 24 hours, whacked them back in put everything on, adjusted the TPS so it's getting a reading of 0.43 closed and 4.09 WOT which seems normal (it was 0.39 and 4.01 or there abouts before I adjusted it).

After adjusting the TPS, the revs are much smoother, but I'm still getting a hesitation as soon as boost goes on.

I encountered a weird problem though. Last night testing and what not, I drove around the block to test it and came back, same problem. But I noticed there was a really weird humming sound coming from the engine.

I opened the bonnet and the sound was coming from the fuel return line (where it connects to the fuel pressure regulator).

It sounds like there is air travelling through it and causing this sound.

I ended up pulling the return hose off and hard wiring the fuel pump to remove the fuel in the lines, while the fuel was coming out it wasn't a smooth flow, it was more jerky so every 0.5 second it will shoot out, stop and shoot out again until there was no fuel left.

About 2 litres of fuel came out which looked brown! But the car has been running extremely rich so I'm guessing I burnt quite a lot of fuel.

I had put new spark plugs before testing it again aswell. It idles fine, I can hit the limiter in neutral all warmed up but as soon as I drive it and go on boost, it just starts misfiring like crazy. It still goes through the revs but really bad popping and farting its way through the rev range. After giving it a hit aswell, the car turned off (started back up fine though).

Could this be an issue with the FPR ? The fuel pump is a brand new Bosch 040 high rate pump and I got a brand new ryco fuel filter on it...

Any opinions will be appreciated.

Thanks guys.

cabramatta Community Regular

cabramatta

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Ended up driving it again tonight with the fresh fuel that I got from BP (98)

car runs flawlessly now.. wtf ?

Another issue now though, when I give it a huge fang and come to a stop, the car turns off unless i rev it a bit in neutral...

Edited by cabramatta

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