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Hesitation Between 4 And 5000 Rpm???

SIR33

By SIR33,
in Engines & Forced Induction

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R33 Impul Rising Star

R33 Impul

Posted
Posted

I have the same problem got my line put on a dyno to find out WTF was happening, ends up it's running hell rich and is gutsing up. The solution SAFC or aftermarket ECU. I'm seriously looking at a WOLF plug and play, depends what plans you have for your car.

Blitz Grand Master

Blitz

Posted
Posted

I will assume you are running higher than factory boost SIR33.

R33 GTS-T's are notorious for having a flatspot in the rev range due to the timing being retarded when running higher boost.

Power FC is your friend.

justified2.4 Enthusiast

justified2.4

Posted
Posted
its starts boosting then when it hits about 3800-4000rpms it reallly struggles, but then after 5000rpm the boost kicks in hard again. standard boost. exhaust. bov and filter.

cheers

I am having a very similar problem, except occasionally after letting off the throttle it starts stumbling really bad and takes a bit to recover as if the MAF is not working properly.

But like your problem, if I stay on the throttle after hesistation it kicks really hard and often spins tires afterwards.

I am using a Techtom MDM-100 to monitor, and it shows that timing is not being pulled and that it is not leaning out. I checked plugs more than once and they are fine and gapped properly. I am only boosting 10 psi MAX.

I am also now running a z32 MAF along with Apex'i S-AFC to try and fix the problem but that is not changing anything.

Very frustrated and do not know where to look next.

SLY33 Mentor

SLY33

Posted
Posted

Blitz is spot on.

Sir33 you have filter and exhaust, meaning you are no longer running std boost, as due to increasing the flow characteristics you pick up a couple of pounds boost.

I had same prob when i first got mine with the same mods as you, but i had a bleed valve. Mine was more a problem when it was very cold, boost spiked, AFM freaks out and the std ECU pulls back the timing.

Power FC is your very best friend!!! In my opinion if you want to mod change the ecu coz they run SOOO much better when tuned for your mods, even just filter and exhaust. No flat spots, just smooth power all the way to the redline.

GT-Rmgedon Collaborator

GT-Rmgedon

Posted
Posted

I had a similar problem except it was misfiring like crazy. I've got one of those old skool Apexi S-AFC's and whacked the car onto the dyno. Gapped the plugs and advanced the timing ever so slightly - Problem solved. I am running standard ecu 2 as well as aftermarket zorst and filter. I'd be checking what kinda spark plugs you have also if they weren't recently installed.

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