s13/14 ka24de needing 91octane+? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

jvega · 03-06-2012, 08:03 PM

Hello, i have a question.

Why would my car (89 240sx W/ 96 ka24de) need the best gas at the pump?

l notice when i put the cheap gas on this car, it tends to "bog" at WOT higher rpm. The other night it shut off completely when i went to the Mountain.
So higher elevation makes it worse with this cheap gas. ?

The engine is stock besides an air intake and filter, and a cat back.
It is using the stock 96 240sx ecu with the complete 96 engine.

Any input would help. Thanks

g00se · 03-06-2012, 08:10 PM

I think there is something wrong with your car other than the octane considering it dies.. have you done routine maint?

n8RPS13 · 03-06-2012, 08:39 PM

MAF is probably going bad...or TPS sensor, maybe even your IACV.

jvega · 03-06-2012, 08:59 PM

Quote:

Originally Posted by g00se

I think there is something wrong with your car other than the octane considering it dies.. have you done routine maint?

i gave it an oil change like 3 weeks ago and checked/cleaned the spark plugs.
Remember it only 'bogs' with cheap gas at higher rpm and wot. The only time it died was at a higher elevation, about 3k ft up.

AsleepAltima · 03-06-2012, 09:05 PM

high octane is the same quality as low octane - it just burns slower.
are you using the correct heat range plugs?

cdlong · 03-06-2012, 09:16 PM

High altitude also lowers the need for octane, hence why where I live (6000 feet), regular is 85, mid is 87, and premium is 89 or 91 depending on the station. I've been putting regular in my car for years with no problems like yours. There's something else wrong with your car.

jvega · 03-06-2012, 09:23 PM

Quote:

Originally Posted by AsleepAltima

high octane is the same quality as low octane - it just burns slower.
are you using the correct heat range plugs?

i know the spark plugs are ngk iridium's, i think they are 7's but not sure. I willl check tomorrow.

AsleepAltima · 03-06-2012, 09:33 PM

7's are too cold for a stock engine. you should be running 5's. 7's will make the engine sluggish, as you are describing.

jvega · 03-07-2012, 07:40 PM

Quote:

Originally Posted by AsleepAltima

7's are too cold for a stock engine. you should be running 5's. 7's will make the engine sluggish, as you are describing.

hey i checked the plugs today and they are 5's. Idk what it could be...

AsleepAltima · 03-07-2012, 07:50 PM

whats your gap set to?

jvega · 03-13-2012, 09:56 PM

Quote:

Originally Posted by AsleepAltima

whats your gap set to?

Alright, sorry i took a couple days, but the gaps are set to .044 on NGK bkr5eix-11 spark plugs.

AsleepAltima · 03-13-2012, 10:50 PM

that sounds about right - i believe its .044-.047 so youre right there. the problem is, neither octane, plugs or gaps will make it completely shut off. have you tried replacing the fuel pump relay? sometimes, when the relays get old, they dont push the same voltage to the fuel pump as they used to and the pump either stops working or works too slowly for the load the engine is asking for. after a drive, pop the hood and see if any of the relays in the fuse box behind the battery are overly hot.

jvega · 03-30-2012, 03:58 PM

UPDATE.

It was the fuel pump.. lol..
I changed the fuel pump and it hasn't given me any problems.

03-06-2012, 08:03 PM	#1
jvega Leaky Injector Join Date: Nov 2010 Location: arizona Age: 36 Posts: 133 Trader Rating: (1) Feedback Score: 1 reviews	s13/14 ka24de needing 91octane+? Hello, i have a question. Why would my car (89 240sx W/ 96 ka24de) need the best gas at the pump? l notice when i put the cheap gas on this car, it tends to "bog" at WOT higher rpm. The other night it shut off completely when i went to the Mountain. So higher elevation makes it worse with this cheap gas. ? The engine is stock besides an air intake and filter, and a cat back. It is using the stock 96 240sx ecu with the complete 96 engine. Any input would help. Thanks

03-06-2012, 08:39 PM	#3
n8RPS13 Zilvia FREAK! Join Date: Sep 2009 Location: New Smyrna Beach Posts: 1,296 Trader Rating: (22) Feedback Score: 22 reviews	MAF is probably going bad...or TPS sensor, maybe even your IACV. __________________ WASTED I AM!

03-06-2012, 09:16 PM	#6
cdlong Nissanaholic! Join Date: Jun 2003 Location: Colorado Springs Age: 44 Posts: 1,865 Trader Rating: (0) Rides Gallery: cdlong Feedback Score: 0 reviews	High altitude also lowers the need for octane, hence why where I live (6000 feet), regular is 85, mid is 87, and premium is 89 or 91 depending on the station. I've been putting regular in my car for years with no problems like yours. There's something else wrong with your car. __________________

03-06-2012, 08:10 PM	#2
g00se Zilvia Junkie Join Date: Aug 2008 Location: CA Posts: 383 Trader Rating: (7) Feedback Score: 7 reviews	I think there is something wrong with your car other than the octane considering it dies.. have you done routine maint?

03-06-2012, 09:05 PM	#5
AsleepAltima Zilvia Addict Join Date: Aug 2006 Location: Ontario, Ca Age: 52 Posts: 667 Trader Rating: (8) Feedback Score: 8 reviews	high octane is the same quality as low octane - it just burns slower. are you using the correct heat range plugs?

03-06-2012, 09:33 PM	#8
AsleepAltima Zilvia Addict Join Date: Aug 2006 Location: Ontario, Ca Age: 52 Posts: 667 Trader Rating: (8) Feedback Score: 8 reviews	7's are too cold for a stock engine. you should be running 5's. 7's will make the engine sluggish, as you are describing.

03-07-2012, 07:50 PM	#10
AsleepAltima Zilvia Addict Join Date: Aug 2006 Location: Ontario, Ca Age: 52 Posts: 667 Trader Rating: (8) Feedback Score: 8 reviews	whats your gap set to?

03-13-2012, 10:50 PM	#12
AsleepAltima Zilvia Addict Join Date: Aug 2006 Location: Ontario, Ca Age: 52 Posts: 667 Trader Rating: (8) Feedback Score: 8 reviews	that sounds about right - i believe its .044-.047 so youre right there. the problem is, neither octane, plugs or gaps will make it completely shut off. have you tried replacing the fuel pump relay? sometimes, when the relays get old, they dont push the same voltage to the fuel pump as they used to and the pump either stops working or works too slowly for the load the engine is asking for. after a drive, pop the hood and see if any of the relays in the fuse box behind the battery are overly hot.

03-30-2012, 03:58 PM	#13
jvega Leaky Injector Join Date: Nov 2010 Location: arizona Age: 36 Posts: 133 Trader Rating: (1) Feedback Score: 1 reviews	UPDATE. It was the fuel pump.. lol.. I changed the fuel pump and it hasn't given me any problems.