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

clutch187 · 12-25-2011, 04:55 PM

Hello my car seems to run and drives fine, but the spark plugs are telling me otherwise and car has no power. the insulators are chalky white like they were when brand new. ive replaced the fuel pump cause it was getting really weak, replace the fuel filter with a new z32 one, fixed the wiring to the knock sensor cause ecu was always saying it was bad, fixed all exhaust leaks and fixed all vac leaks i could find (starting fluid method). checked and redid timing numerous times. i can't figure it out as to why my cars running lean. can anyone give me and advise on what to check next or how to fix my problem. the car in a 92 nissan 240sx s spd with a ka24de.

SFL Jon · 12-25-2011, 04:57 PM

Coil packs?

New spark plugs?

clutch187 · 12-25-2011, 05:07 PM

plugs are brand new and as for coil pack, it was on there when i bought it. I dont understand why plugs or coil pack would have anything to do with a lean condition. doesnt lean mean its getting too much air and not enough fuel?

Chronox2 · 12-25-2011, 08:39 PM

If there is no problem with the spark then it could be your MAS sending a wrong signal of air, making the air/fuel ratio incoherent. Do a compression test, and a leak test. Try to find a air leak somewhere, some times BOV gets leaky.

clutch187 · 12-25-2011, 08:58 PM

so the maf wont always throw a CEL. i dont have any stored codes and the cars not turbod so i can rule the bov out lol. ill do compression test tomorrow

clutch187 · 12-26-2011, 04:44 PM

ive checked maf and i get anywhere from .98v to 1.2v at idle. compression was good all the way across the board. anything else to check

Chronox2 · 12-26-2011, 05:25 PM

How old are the injectors? Check the factory pulse and flow of the injectors.

clutch187 · 12-26-2011, 06:42 PM

I have 2 set of injectors and I've already changes them out last week and didn't change anything. I have a question though. I check the maf ground with the car running and it was .86 on 20k ohm scale when I thought it should read 0. Is that right

12-25-2011, 04:55 PM	#1
clutch187 Join Date: Nov 2011 Location: indiana Age: 38 Posts: 8 Trader Rating: (0) Feedback Score: 0 reviews	running lean Hello my car seems to run and drives fine, but the spark plugs are telling me otherwise and car has no power. the insulators are chalky white like they were when brand new. ive replaced the fuel pump cause it was getting really weak, replace the fuel filter with a new z32 one, fixed the wiring to the knock sensor cause ecu was always saying it was bad, fixed all exhaust leaks and fixed all vac leaks i could find (starting fluid method). checked and redid timing numerous times. i can't figure it out as to why my cars running lean. can anyone give me and advise on what to check next or how to fix my problem. the car in a 92 nissan 240sx s spd with a ka24de.

12-25-2011, 04:57 PM	#2
SFL Jon Join Date: Mar 2011 Location: West Palm Beach, FL Posts: 13 Trader Rating: (0) Feedback Score: 0 reviews	Coil packs? New spark plugs?

12-25-2011, 05:07 PM	#3
clutch187 Join Date: Nov 2011 Location: indiana Age: 38 Posts: 8 Trader Rating: (0) Feedback Score: 0 reviews	plugs are brand new and as for coil pack, it was on there when i bought it. I dont understand why plugs or coil pack would have anything to do with a lean condition. doesnt lean mean its getting too much air and not enough fuel?

12-25-2011, 08:39 PM	#4
Chronox2 Leaky Injector Join Date: Sep 2011 Location: FL Posts: 103 Trader Rating: (0) Feedback Score: 0 reviews	If there is no problem with the spark then it could be your MAS sending a wrong signal of air, making the air/fuel ratio incoherent. Do a compression test, and a leak test. Try to find a air leak somewhere, some times BOV gets leaky.

12-25-2011, 08:58 PM	#5
clutch187 Join Date: Nov 2011 Location: indiana Age: 38 Posts: 8 Trader Rating: (0) Feedback Score: 0 reviews	so the maf wont always throw a CEL. i dont have any stored codes and the cars not turbod so i can rule the bov out lol. ill do compression test tomorrow

12-26-2011, 04:44 PM	#6
clutch187 Join Date: Nov 2011 Location: indiana Age: 38 Posts: 8 Trader Rating: (0) Feedback Score: 0 reviews	ive checked maf and i get anywhere from .98v to 1.2v at idle. compression was good all the way across the board. anything else to check

12-26-2011, 05:25 PM	#7
Chronox2 Leaky Injector Join Date: Sep 2011 Location: FL Posts: 103 Trader Rating: (0) Feedback Score: 0 reviews	How old are the injectors? Check the factory pulse and flow of the injectors.

12-26-2011, 06:42 PM	#8
clutch187 Join Date: Nov 2011 Location: indiana Age: 38 Posts: 8 Trader Rating: (0) Feedback Score: 0 reviews	I have 2 set of injectors and I've already changes them out last week and didn't change anything. I have a question though. I check the maf ground with the car running and it was .86 on 20k ohm scale when I thought it should read 0. Is that right