Gas Mileage sucks!! please help! - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Kenrik · 08-22-2005, 09:32 PM

ok so I just got back from the gas station and I figured out i'm getting 13MPG!!! that totally sucks I drive hard but not THAT hard... there must be something wrong with my car... I have within the past month replaced the O2 sensor, Coolant sensor, put in new NGK plugs/wires.. Cleaned the MAF. etc... I also have a brand new Cone Filter, Reset the ECU etc.. I checked the PSI on all my tires before I tested my mileage... WTF is wrong with my car!! The only thing different that I did from normal is that I was running 89 octane when I usually run 93 I noticed that the car had less power running the 89 but it can't have made THAT big a difference on mileage... is my ECU toast? There must be something that is causing my car to run super rich and I need to figure out what.. Any Ideas??? any help would be GREAT!!

1989 KA24E 140k miles.

Pred · 05-18-2006, 06:37 PM

i have the same problem too. id like to know as well. any one? I recently changed my injector o-rings. previous owner changed 2 injectors. All injectors are "clicking" but I havent flow tested them or anything. ECU throws code 45 "injector fuel leak". I smell no gas, no gas anywhere. It's driving me nuts and gas is expensive now. This car gets worse mileage then my turbo car. please help!?

alexchanman · 05-18-2006, 07:55 PM

clean your air filter and throttle body, might help a little. also try running some cylinder cleaner tooo, my friend got some of his mpg back from doing that.

C. Senor · 05-18-2006, 08:00 PM

do you guys have audio systems in your car that run extensive wiring. i had a similar problem, when i have a system, the wiring was messing something up and i would literally waste fuel.

Pred · 06-07-2006, 12:06 PM

All I have is a Pioneer deck and upgraded speakers. I had a mechanic check out my fuel pressure, compression, timing. he said its ok. i clean the iav lowered my idle down to 700-800. Had bad fuel smell in side the cabin so I changed the hoses in the rear tank and also the o-ring above it. I changed the injector o-rings (lubed it up with vaseline).we also check the injectors and they seem to be working fine (no leaks around the area). Pulled out the spark plugs and cylinder 1 was rich, cylinder 2,3,4 were lean. ?__?. The car is bone stock with just a K&N drop-in filter. Still get CEL code 45 everyday. Sometimes it comes for a few mins, sometimes it stays on for days. Its pissing me off.

aznpoopy · 06-07-2006, 03:44 PM

pred, i bet your inj #1 is toast. if you're sure your injector o-rings are good, try switching injector 1 with injector 2. run it. if cyl 2 is rich and then you know the problem.

i suppose if injector 1 were really fucked, 2 3 and 4 could be lean... too much fuel goes out #1 leaving less for the rest. 1 is the first one sequentially on the rail.

the fuel smell in the rear is prob from the exhaust. get your nose there while its running and smell it.

Pred · 06-07-2006, 05:41 PM

i guess illl try changing the injector.(people keep outbidding me on ebay lol) all the gas smell went away after i changed the oring on the fuel tank and hoses from the sender. Ive changed the injector orings 3 times within the past two years. (most recent one was last week)

P4rD0nM3 · 06-07-2006, 08:17 PM

Check Odometer if it's stuck. I thought I only have 15mpg but my odometer get's stuck from time to time...

Ricks15 · 06-07-2006, 08:31 PM

did you change the fuel filter?? maybe the cat too is all cloged up and could be causeing that you're engine is burning excessive gas, I know for a fact cuz I had the same problem you have but I fixed it just by replacing the O2 sensor

I hope my damn KA dont go back to the rich side

.

Pred · 06-08-2006, 02:07 AM

changed the fuel filter 2 weeks ago. O2 sensor was changed about 3months ago. It's a cheap Bosch 1wire type.. maybe it's a POS?
The stuck odometer wouldnt explain my CEL though. I hope it's just that one bad injector.

06-07-2006, 08:31 PM	#9
Ricks15 Nissanaholic! Join Date: Apr 2005 Location: Los Angeles, CA Age: 39 Posts: 1,661 Trader Rating: (1) Feedback Score: 1 reviews	did you change the fuel filter?? maybe the cat too is all cloged up and could be causeing that you're engine is burning excessive gas, I know for a fact cuz I had the same problem you have but I fixed it just by replacing the O2 sensor I hope my damn KA dont go back to the rich side. __________________

08-22-2005, 09:32 PM	#1
Kenrik Leaky Injector Join Date: Aug 2005 Location: Fort Lauderdale Posts: 50 Trader Rating: (0) Feedback Score: 0 reviews	Gas Mileage sucks!! please help! ok so I just got back from the gas station and I figured out i'm getting 13MPG!!! that totally sucks I drive hard but not THAT hard... there must be something wrong with my car... I have within the past month replaced the O2 sensor, Coolant sensor, put in new NGK plugs/wires.. Cleaned the MAF. etc... I also have a brand new Cone Filter, Reset the ECU etc.. I checked the PSI on all my tires before I tested my mileage... WTF is wrong with my car!! The only thing different that I did from normal is that I was running 89 octane when I usually run 93 I noticed that the car had less power running the 89 but it can't have made THAT big a difference on mileage... is my ECU toast? There must be something that is causing my car to run super rich and I need to figure out what.. Any Ideas??? any help would be GREAT!! 1989 KA24E 140k miles.

05-18-2006, 06:37 PM	#2
Pred Join Date: Jan 2006 Location: San Francisco Posts: 27 Trader Rating: (0) Feedback Score: 0 reviews	i have the same problem too. id like to know as well. any one? I recently changed my injector o-rings. previous owner changed 2 injectors. All injectors are "clicking" but I havent flow tested them or anything. ECU throws code 45 "injector fuel leak". I smell no gas, no gas anywhere. It's driving me nuts and gas is expensive now. This car gets worse mileage then my turbo car. please help!?

05-18-2006, 07:55 PM	#3
alexchanman Zilvia Junkie Join Date: Jun 2005 Location: boston, ma Posts: 428 Trader Rating: (0) Feedback Score: 0 reviews	clean your air filter and throttle body, might help a little. also try running some cylinder cleaner tooo, my friend got some of his mpg back from doing that.

05-18-2006, 08:00 PM	#4
C. Senor Post Whore! Join Date: May 2006 Location: cali Posts: 3,488 Trader Rating: (3) Feedback Score: 3 reviews	do you guys have audio systems in your car that run extensive wiring. i had a similar problem, when i have a system, the wiring was messing something up and i would literally waste fuel.

06-07-2006, 12:06 PM	#5
Pred Join Date: Jan 2006 Location: San Francisco Posts: 27 Trader Rating: (0) Feedback Score: 0 reviews	All I have is a Pioneer deck and upgraded speakers. I had a mechanic check out my fuel pressure, compression, timing. he said its ok. i clean the iav lowered my idle down to 700-800. Had bad fuel smell in side the cabin so I changed the hoses in the rear tank and also the o-ring above it. I changed the injector o-rings (lubed it up with vaseline).we also check the injectors and they seem to be working fine (no leaks around the area). Pulled out the spark plugs and cylinder 1 was rich, cylinder 2,3,4 were lean. ?__?. The car is bone stock with just a K&N drop-in filter. Still get CEL code 45 everyday. Sometimes it comes for a few mins, sometimes it stays on for days. Its pissing me off.

06-07-2006, 03:44 PM	#6
aznpoopy Post Whore! Join Date: Mar 2003 Location: New Jersey Age: 44 Posts: 5,013 Trader Rating: (1) Feedback Score: 1 reviews	pred, i bet your inj #1 is toast. if you're sure your injector o-rings are good, try switching injector 1 with injector 2. run it. if cyl 2 is rich and then you know the problem. i suppose if injector 1 were really fucked, 2 3 and 4 could be lean... too much fuel goes out #1 leaving less for the rest. 1 is the first one sequentially on the rail. the fuel smell in the rear is prob from the exhaust. get your nose there while its running and smell it.

06-07-2006, 05:41 PM	#7
Pred Join Date: Jan 2006 Location: San Francisco Posts: 27 Trader Rating: (0) Feedback Score: 0 reviews	i guess illl try changing the injector.(people keep outbidding me on ebay lol) all the gas smell went away after i changed the oring on the fuel tank and hoses from the sender. Ive changed the injector orings 3 times within the past two years. (most recent one was last week)

06-07-2006, 08:17 PM	#8
P4rD0nM3 Zilvia FREAK! Join Date: Jun 2005 Location: Not Applicable Posts: 1,183 Trader Rating: (0) Feedback Score: 0 reviews	Check Odometer if it's stuck. I thought I only have 15mpg but my odometer get's stuck from time to time...

06-08-2006, 02:07 AM	#10
Pred Join Date: Jan 2006 Location: San Francisco Posts: 27 Trader Rating: (0) Feedback Score: 0 reviews	changed the fuel filter 2 weeks ago. O2 sensor was changed about 3months ago. It's a cheap Bosch 1wire type.. maybe it's a POS? The stuck odometer wouldnt explain my CEL though. I hope it's just that one bad injector.