Problem at around 4k rpms!?!? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

AdrenalineS14 · 03-30-2011, 11:42 PM

Hello Zilvians, i have a small problem... at least i think its a small prob, I own a 95 S14 with a fully built SR in it and for some reason at around 4k rpms it seems to lose or break up in power other than that the motor starts perfect and drives real smooth under 4k... i bought this car built and it was blowing alittle smoke so me and the previous owner pulled the motor out and replaced the piston rings cause the ring gap was alittle off/or worn, the motor was built about 2 years ago and performed perfectly, it does have a power fc and a greddy profec b spec 2 and was re-tuned(base tune) before we pulled the engine and ran real nice! Then after the engine pull the previous owner accidently set the fc on stock settings... I think

im def going to get a re-tune and this time a full tune on a dyno hoping that the car just needs that. Just wanna hear what you all think about my prob

.... ps i still blow a tiny bit of smoke only when idleing from a cold start i was thinking it was the block cause cylinder 2 was wet hince the reason we replaced the rings but now I think maybe the valves are a tiny bit off or maybe the valve seals are a little worn idk lol... now im just ranting

but yeah help me out plz lol THANKS

AdrenalineS14 · 03-31-2011, 05:51 PM

anybody? bump

KiLLeR2001 · 03-31-2011, 08:44 PM

Sounds like a similar problem I had with my SR. Turned out to be a coilpack.

herbieS13 · 03-31-2011, 09:02 PM

go into settings in your pfc commander click on boost see what theyre all set at 1. 2. 3. 4. i.e. 1 - 15 2 - 30 3 - 50 4 - 75 just an example of what you should see your boost settings will be different...back on subject, look at the highest number i.e. 4- 75, now look at what your boost is set at if its apx the same number try turning down the boost. if that fixes it, it was fuel cut

lmk if that was the problem

edit::: check your boost via boost controller, also im assuming 4000rpm WOT right? what boost levels are u hitting and whats your AFR

nevertheless · 03-31-2011, 09:18 PM

Yeah It sounds like its something wrong with your computer, my friend just bought an Sr 240, and we noticed the Ecu was messed with, tightened up some wires and it finally went past 4k.

AdrenalineS14 · 03-31-2011, 09:20 PM

Can't do nothing cause there's an event in Pheonix tomorrow!...without my car

hope its not the coilpacks... i do need to change the plugs though

and ill check the FC Commander that herbie suggested as soon as im back in the next few days thanks guys and ill report back to see what i find

03-30-2011, 11:42 PM	#1
AdrenalineS14 Zilvia Member Join Date: Mar 2011 Location: Tucson, AZ Age: 39 Posts: 202 Trader Rating: (1) Feedback Score: 1 reviews	Problem at around 4k rpms!?!? Hello Zilvians, i have a small problem... at least i think its a small prob, I own a 95 S14 with a fully built SR in it and for some reason at around 4k rpms it seems to lose or break up in power other than that the motor starts perfect and drives real smooth under 4k... i bought this car built and it was blowing alittle smoke so me and the previous owner pulled the motor out and replaced the piston rings cause the ring gap was alittle off/or worn, the motor was built about 2 years ago and performed perfectly, it does have a power fc and a greddy profec b spec 2 and was re-tuned(base tune) before we pulled the engine and ran real nice! Then after the engine pull the previous owner accidently set the fc on stock settings... I think im def going to get a re-tune and this time a full tune on a dyno hoping that the car just needs that. Just wanna hear what you all think about my prob .... ps i still blow a tiny bit of smoke only when idleing from a cold start i was thinking it was the block cause cylinder 2 was wet hince the reason we replaced the rings but now I think maybe the valves are a tiny bit off or maybe the valve seals are a little worn idk lol... now im just ranting but yeah help me out plz lol THANKS

03-31-2011, 08:44 PM	#3
KiLLeR2001 Post Whore! Join Date: Jun 2007 Location: オーランドフロリダ Posts: 7,955 Trader Rating: (46) Feedback Score: 46 reviews	Sounds like a similar problem I had with my SR. Turned out to be a coilpack. __________________

03-31-2011, 09:18 PM	#5
nevertheless Zilvia Junkie Join Date: Jan 2009 Location: omaha, ne Age: 34 Posts: 502 Trader Rating: (5) Feedback Score: 5 reviews	Yeah It sounds like its something wrong with your computer, my friend just bought an Sr 240, and we noticed the Ecu was messed with, tightened up some wires and it finally went past 4k. __________________ Jessefuckinwood Street Prowl

03-31-2011, 05:51 PM	#2
AdrenalineS14 Zilvia Member Join Date: Mar 2011 Location: Tucson, AZ Age: 39 Posts: 202 Trader Rating: (1) Feedback Score: 1 reviews	anybody? bump

03-31-2011, 09:02 PM	#4
herbieS13 Zilvia Junkie Join Date: Nov 2008 Location: FT Campbell, KY. Posts: 329 Trader Rating: (2) Feedback Score: 2 reviews	go into settings in your pfc commander click on boost see what theyre all set at 1. 2. 3. 4. i.e. 1 - 15 2 - 30 3 - 50 4 - 75 just an example of what you should see your boost settings will be different...back on subject, look at the highest number i.e. 4- 75, now look at what your boost is set at if its apx the same number try turning down the boost. if that fixes it, it was fuel cut lmk if that was the problem edit::: check your boost via boost controller, also im assuming 4000rpm WOT right? what boost levels are u hitting and whats your AFR

03-31-2011, 09:20 PM	#6
AdrenalineS14 Zilvia Member Join Date: Mar 2011 Location: Tucson, AZ Age: 39 Posts: 202 Trader Rating: (1) Feedback Score: 1 reviews	Can't do nothing cause there's an event in Pheonix tomorrow!...without my car hope its not the coilpacks... i do need to change the plugs though and ill check the FC Commander that herbie suggested as soon as im back in the next few days thanks guys and ill report back to see what i find