Fuel injector check. - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

soryu · 11-24-2012, 08:39 PM

so, after doing some hard pulls in my240 KA all 155Hp 6800rpm.
got home,sleep,wake up,turn car on engine shaking,car also and sounds like a WRX.(bogging650-700rpm but not dying, does rev up )
i pulled first spark plug wire nothing.
second wire bog harder.
3rd bogharder.
4th bogharder.
i read a couple of other threads . so looks like a bad fuel injector.
are there any other tests i can do before pulling it out?
i'll be checking resistance with OHM meter tomorrow.
how much does having all 4 cleaned at a shop?

Nizzan4u2nv · 11-24-2012, 10:13 PM

Pull the injector harness on #1 cylinder and if nothing changes then the injector is dead. I dont think cleaning will bring an injector back from the dead.

cotbu · 11-24-2012, 11:19 PM

Damn....! all you did was narrow down the cylinder with a power balance test. unless you can tell that it's fuel or spark that was missing. Try Ωing the injectors?
So your next step is to check for spark and fuel for those dead cylinders.
remove the plugs, check for spark, remove the fuel rail check and for spray. You can place the injectors over a rag, cardboard, in empty soda bottles or over a bucket. just keep away from open sparks or flames. ask an adult for help! Or just replace injectors, plug wires, sparkplugs, rotor and cap, ect.

soryu · 11-25-2012, 12:05 AM

i pulled spark plug wire from cylinder, nothing happened.
is that the same as pulling injector harness?
when i check for OHM's if there is nothing from injector that should meen it's ded?

cotbu · 11-25-2012, 12:21 AM

Yes,and yes but you'll probably get something from Ωing the injectors. they are high impedance so a low reading would indicate a failing injector as well.

I would pull the rail and check for spray, and leaks.
And pull the plugs to check for spark and or fouling.

s13livin · 11-25-2012, 01:36 AM

Quote:

Originally Posted by soryu

i pulled spark plug wire from cylinder, nothing happened.
is that the same as pulling injector harness?
when i check for OHM's if there is nothing from injector that should meen it's ded?

gathering from your info, if you pulled up the wire and nothing happened that cylinders dead, could be just the plug or something more. if you pull up any wire the motor should come to a rough low idle and like he said before if nothing happens when u pull injector harness that injectors obviously dead

soryu · 11-25-2012, 02:01 AM

Plugs checked, still look new.

Nizzan4u2nv · 11-25-2012, 02:22 AM

Pull the plug wire on number one and ground it to the valve cover to check for spark. If there's spark and the plug is good then has to be the injector. There's no need to pull the fuel rail. If the injector is getting proper voltage and or the resistance is out of spec then the injector is dead. If it was leaking it would run rich on that cylinder not be completely dead. The power balance test would show a change if it was leaking and the plug would be fouled. My money is on dead injector. Not an uncommon orccurence on these cars. It's happened to me a few times myself.

s14boy · 11-25-2012, 02:53 AM

Quote:

Originally Posted by Nizzan4u2nv

Pull the plug wire on number one and ground it to the valve cover to check for spark. If there's spark and the plug is good then has to be the injector. There's no need to pull the fuel rail. If the injector is getting proper voltage and or the resistance is out of spec then the injector is dead. If it was leaking it would run rich on that cylinder not be completely dead. The power balance test would show a change if it was leaking and the plug would be fouled. My money is on dead injector. Not an uncommon orccurence on these cars. It's happened to me a few times myself.

i agree its the injectors. happens to alot of 240's

soryu · 11-25-2012, 02:28 PM

checked ohms today (0.0,11.3,11.4,11.3)

installed new injector (used) back to normal.

Croustibat · 11-26-2012, 11:54 AM

Quote:

Originally Posted by cotbu

Yes,and yes but you'll probably get something from Ωing the injectors. they are high impedance so a low reading would indicate a failing injector as well.

I would pull the rail and check for spray, and leaks.
And pull the plugs to check for spark and or fouling.

Just to clarify this little thing, "high impedance" means 10-13ohms , where low impedance is around 3ohms.

"High impedance" is still a very low reading on an ohm meter

11-24-2012, 10:13 PM	#2
Nizzan4u2nv Zilvia FREAK! Join Date: Oct 2003 Location: San Diego Age: 40 Posts: 1,226 Trader Rating: (3) Feedback Score: 3 reviews	Pull the injector harness on #1 cylinder and if nothing changes then the injector is dead. I dont think cleaning will bring an injector back from the dead. __________________

11-24-2012, 11:19 PM	#3
cotbu Post Whore! Join Date: Sep 2005 Location: SWFL Age: 50 Posts: 3,318 Trader Rating: (3) Feedback Score: 3 reviews	Damn....! all you did was narrow down the cylinder with a power balance test. unless you can tell that it's fuel or spark that was missing. Try Ωing the injectors? So your next step is to check for spark and fuel for those dead cylinders. remove the plugs, check for spark, remove the fuel rail check and for spray. You can place the injectors over a rag, cardboard, in empty soda bottles or over a bucket. just keep away from open sparks or flames. ask an adult for help! Or just replace injectors, plug wires, sparkplugs, rotor and cap, ect. __________________ LoverTechnologies "Half Broken Things!"

11-25-2012, 12:21 AM	#5
cotbu Post Whore! Join Date: Sep 2005 Location: SWFL Age: 50 Posts: 3,318 Trader Rating: (3) Feedback Score: 3 reviews	Yes,and yes but you'll probably get something from Ωing the injectors. they are high impedance so a low reading would indicate a failing injector as well. I would pull the rail and check for spray, and leaks. And pull the plugs to check for spark and or fouling. __________________ LoverTechnologies "Half Broken Things!"

11-25-2012, 02:22 AM	#8
Nizzan4u2nv Zilvia FREAK! Join Date: Oct 2003 Location: San Diego Age: 40 Posts: 1,226 Trader Rating: (3) Feedback Score: 3 reviews	Pull the plug wire on number one and ground it to the valve cover to check for spark. If there's spark and the plug is good then has to be the injector. There's no need to pull the fuel rail. If the injector is getting proper voltage and or the resistance is out of spec then the injector is dead. If it was leaking it would run rich on that cylinder not be completely dead. The power balance test would show a change if it was leaking and the plug would be fouled. My money is on dead injector. Not an uncommon orccurence on these cars. It's happened to me a few times myself. __________________

11-25-2012, 02:28 PM	#10
soryu Zilvia FREAK! Join Date: Jul 2011 Location: Socal, I.E. Posts: 1,199 Trader Rating: (17) Feedback Score: 17 reviews	checked ohms today (0.0,11.3,11.4,11.3) installed new injector (used) back to normal. Last edited by soryu; 11-26-2012 at 12:52 AM.. Reason: Update

11-24-2012, 08:39 PM	#1
soryu Zilvia FREAK! Join Date: Jul 2011 Location: Socal, I.E. Posts: 1,199 Trader Rating: (17) Feedback Score: 17 reviews	Fuel injector check. so, after doing some hard pulls in my240 KA all 155Hp 6800rpm. got home,sleep,wake up,turn car on engine shaking,car also and sounds like a WRX.(bogging650-700rpm but not dying, does rev up ) i pulled first spark plug wire nothing. second wire bog harder. 3rd bogharder. 4th bogharder. i read a couple of other threads . so looks like a bad fuel injector. are there any other tests i can do before pulling it out? i'll be checking resistance with OHM meter tomorrow. how much does having all 4 cleaned at a shop? Last edited by soryu; 11-25-2012 at 12:08 AM.. Reason: add info

11-25-2012, 12:05 AM	#4
soryu Zilvia FREAK! Join Date: Jul 2011 Location: Socal, I.E. Posts: 1,199 Trader Rating: (17) Feedback Score: 17 reviews	i pulled spark plug wire from cylinder, nothing happened. is that the same as pulling injector harness? when i check for OHM's if there is nothing from injector that should meen it's ded?

11-25-2012, 02:01 AM	#7
soryu Zilvia FREAK! Join Date: Jul 2011 Location: Socal, I.E. Posts: 1,199 Trader Rating: (17) Feedback Score: 17 reviews	Plugs checked, still look new.