rb20 hesitation - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

minor_times · 01-28-2010, 04:02 PM

So today I installed a mbc and played with the boost levels. When I got it set to ~10psi I accelerated at wot and got hesitation and a rapid backfire(ish) sound from the exhaust once full boost ~12psi was achieved. I then brought boost back down to 8-9psi and it ran just fine. Im guessing this is either a fuel or spark plug issue, correct me if im wrong.

stock smic
t28
safc2 (untuned)

Couped_up'd · 01-28-2010, 07:15 PM

Lower the spark plug gap to around .8

(My freinds rb20det did this SAME thing)

If that does not fix it, then I would look into the coil packs.

minor_times · 01-28-2010, 07:32 PM

word, thanks

Zacho · 01-28-2010, 07:43 PM

NGK BKR7E plugs are money for >10 psi on an rb20/25 from my experience. Pre gapped to .8, and not bad price.

eklips3 · 01-29-2010, 01:25 AM

yep , i had this on my car exact same symptoms.
like the previous posts , check your plugs , play with your gap, i had to tinker with my gap a few times to get it bang on ... i wish i wrote it down somwhere cause i threw the plugs out. but even after that my car still hesitated a bit so i got new coil packs and smooth quick sailing from there

Couped_up'd · 01-29-2010, 08:21 AM

I did the Gm coil pack convertion. Love it!

01-28-2010, 04:02 PM	#1
minor_times Leaky Injector Join Date: Aug 2009 Location: Fredericksburg, Virginia Age: 30 Posts: 81 Trader Rating: (3) Feedback Score: 3 reviews	rb20 hesitation So today I installed a mbc and played with the boost levels. When I got it set to ~10psi I accelerated at wot and got hesitation and a rapid backfire(ish) sound from the exhaust once full boost ~12psi was achieved. I then brought boost back down to 8-9psi and it ran just fine. Im guessing this is either a fuel or spark plug issue, correct me if im wrong. stock smic t28 safc2 (untuned) __________________ RBEAZY =D

01-28-2010, 07:15 PM	#2
Couped_up'd Zilvia FREAK! Join Date: Feb 2009 Location: Candy Mountain Posts: 1,119 Trader Rating: (47) Feedback Score: 47 reviews	Lower the spark plug gap to around .8 (My freinds rb20det did this SAME thing) If that does not fix it, then I would look into the coil packs. __________________

01-28-2010, 07:32 PM	#3
minor_times Leaky Injector Join Date: Aug 2009 Location: Fredericksburg, Virginia Age: 30 Posts: 81 Trader Rating: (3) Feedback Score: 3 reviews	word, thanks __________________ RBEAZY =D

01-29-2010, 01:25 AM	#5
eklips3 Zilvia Addict Join Date: Apr 2008 Location: Calgary Canada Age: 31 Posts: 626 Trader Rating: (3) Feedback Score: 3 reviews	yep , i had this on my car exact same symptoms. like the previous posts , check your plugs , play with your gap, i had to tinker with my gap a few times to get it bang on ... i wish i wrote it down somwhere cause i threw the plugs out. but even after that my car still hesitated a bit so i got new coil packs and smooth quick sailing from there __________________ 1992 240sx (RB20. [email protected])

01-29-2010, 08:21 AM	#6
Couped_up'd Zilvia FREAK! Join Date: Feb 2009 Location: Candy Mountain Posts: 1,119 Trader Rating: (47) Feedback Score: 47 reviews	I did the Gm coil pack convertion. Love it! __________________

01-28-2010, 07:43 PM	#4
Zacho Zilvia Member Join Date: Jun 2007 Location: Canada Posts: 217 Trader Rating: (5) Feedback Score: 5 reviews	NGK BKR7E plugs are money for >10 psi on an rb20/25 from my experience. Pre gapped to .8, and not bad price.

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