A POP after every shift or boost - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

komedy · 02-08-2007, 07:47 PM

just change spark plugs in my redtop sr20det. one year past since last sparkplug change . i use the OEM platinums pfr-7b-11 NGKS. i installed the new sparkplugs in at .034 gap. Since the new sparkplugs my cars been getting a blowback at every shift no matter high or low boost. and the car feels very sluggish at mid to high rpms. it sounds loud but goes nowhere like hondas

. You guys recommend increasing or decreasing the sparkplug gap in this kind of situations?? the sparkplug gap should be the problem to this.
its moslty stock with exahaust.
i tryed seaching it but couldnt find a answer to this one.
thank.

clutch kick drifter · 02-08-2007, 07:52 PM

im running 20psi and BKr7e11 gapped at .28 . Thing runs great but it backfires/popz after lots of shifts and shit but it dosent bog. ive had that problem before and one time it was a dime size hole in my cold piipe and the other time was a bad CAS. when it feels sluggish at high/ low rpms is that in boost? Like can you take it up slowly and not get a bog or it beomce sluggish, or is it any throttle it just sucks basically?

komedy · 02-08-2007, 07:57 PM

I see from your statment i can say that since you running higher boost the gap decreases. but since my car is stock and the oem platiums come gaped at .045 i should increase the gap back to that number or close to it.

the thing is i never had backfires from previous spark plug and ran strong at all rpms. its the same spark plug and i gaped it the same. well thanks for the fast reply. im gonna increase the spark plug gap and see what happens.
ill reply back if that fixes the blowbacks and sluggish powerband.

thanks again.

komedy · 02-08-2007, 07:58 PM

correct me if im wrong. any input is grateful.
thanks

staygold24 · 02-08-2007, 07:59 PM

mine does this alot too. I think it might be related to my plugs or a small boostleak somewhere.

Could be from the large walbro I have and stock boost. I dont know, Id like to know the culprit of this also.

komedy · 02-08-2007, 08:01 PM

yeah i can take it up slowly and not bog. but gets sluggish after high rpms. and my boost guage reads normal boost presure also.

komedy · 02-08-2007, 08:02 PM

lol kk ill let you know, im gonna redo the sparkplugs first thing tommorrow morning.

komedy · 02-08-2007, 08:05 PM

hey how long you been driving with the blowbacks. i guess its ok to drive with blowbacks at every shift for a long time?

staygold24 · 02-08-2007, 08:10 PM

mines been doing it since I can remember, I really dont think it can hurt anything. It quieted down after I got an exhaust with a resonator. Im positive I need to gap my plugs though.

I run br7eix and should gap them to .028 but havent yet.

Flybert · 02-08-2007, 08:37 PM

.028 is stock gap for SR.

komedy · 02-08-2007, 09:05 PM

thank you flybert. didnt know that stock gap was .028. i will try decreasing
.034 too .028 and hopw it will fix the blow backs.

02-08-2007, 07:47 PM	#1
komedy Zilvia Member Join Date: Mar 2006 Location: LA Posts: 262 Trader Rating: (0) Feedback Score: 0 reviews	A POP after every shift or boost just change spark plugs in my redtop sr20det. one year past since last sparkplug change . i use the OEM platinums pfr-7b-11 NGKS. i installed the new sparkplugs in at .034 gap. Since the new sparkplugs my cars been getting a blowback at every shift no matter high or low boost. and the car feels very sluggish at mid to high rpms. it sounds loud but goes nowhere like hondas. You guys recommend increasing or decreasing the sparkplug gap in this kind of situations?? the sparkplug gap should be the problem to this. its moslty stock with exahaust. i tryed seaching it but couldnt find a answer to this one. thank.

02-08-2007, 07:52 PM	#2
clutch kick drifter Zilvia Junkie Join Date: Jul 2005 Location: TN Posts: 498 Trader Rating: (0) Feedback Score: 0 reviews	im running 20psi and BKr7e11 gapped at .28 . Thing runs great but it backfires/popz after lots of shifts and shit but it dosent bog. ive had that problem before and one time it was a dime size hole in my cold piipe and the other time was a bad CAS. when it feels sluggish at high/ low rpms is that in boost? Like can you take it up slowly and not get a bog or it beomce sluggish, or is it any throttle it just sucks basically?

02-08-2007, 07:57 PM	#3
komedy Zilvia Member Join Date: Mar 2006 Location: LA Posts: 262 Trader Rating: (0) Feedback Score: 0 reviews	I see from your statment i can say that since you running higher boost the gap decreases. but since my car is stock and the oem platiums come gaped at .045 i should increase the gap back to that number or close to it. the thing is i never had backfires from previous spark plug and ran strong at all rpms. its the same spark plug and i gaped it the same. well thanks for the fast reply. im gonna increase the spark plug gap and see what happens. ill reply back if that fixes the blowbacks and sluggish powerband. thanks again.

02-08-2007, 07:58 PM	#4
komedy Zilvia Member Join Date: Mar 2006 Location: LA Posts: 262 Trader Rating: (0) Feedback Score: 0 reviews	correct me if im wrong. any input is grateful. thanks

02-08-2007, 07:59 PM	#5
staygold24 Zilvia Addict Join Date: Aug 2005 Location: St. Simons Ga Posts: 673 Trader Rating: (0) Feedback Score: 0 reviews	mine does this alot too. I think it might be related to my plugs or a small boostleak somewhere. Could be from the large walbro I have and stock boost. I dont know, Id like to know the culprit of this also.

02-08-2007, 08:01 PM	#6
komedy Zilvia Member Join Date: Mar 2006 Location: LA Posts: 262 Trader Rating: (0) Feedback Score: 0 reviews	yeah i can take it up slowly and not bog. but gets sluggish after high rpms. and my boost guage reads normal boost presure also.

02-08-2007, 08:02 PM	#7
komedy Zilvia Member Join Date: Mar 2006 Location: LA Posts: 262 Trader Rating: (0) Feedback Score: 0 reviews	lol kk ill let you know, im gonna redo the sparkplugs first thing tommorrow morning.

02-08-2007, 08:05 PM	#8
komedy Zilvia Member Join Date: Mar 2006 Location: LA Posts: 262 Trader Rating: (0) Feedback Score: 0 reviews	hey how long you been driving with the blowbacks. i guess its ok to drive with blowbacks at every shift for a long time?

02-08-2007, 08:10 PM	#9
staygold24 Zilvia Addict Join Date: Aug 2005 Location: St. Simons Ga Posts: 673 Trader Rating: (0) Feedback Score: 0 reviews	mines been doing it since I can remember, I really dont think it can hurt anything. It quieted down after I got an exhaust with a resonator. Im positive I need to gap my plugs though. I run br7eix and should gap them to .028 but havent yet.

02-08-2007, 08:37 PM	#10
Flybert Post Whore! Join Date: Mar 2003 Location: none Posts: 3,862 Trader Rating: (7) Feedback Score: 7 reviews	.028 is stock gap for SR.

02-08-2007, 09:05 PM	#11
komedy Zilvia Member Join Date: Mar 2006 Location: LA Posts: 262 Trader Rating: (0) Feedback Score: 0 reviews	thank you flybert. didnt know that stock gap was .028. i will try decreasing .034 too .028 and hopw it will fix the blow backs.