90 300zx na code 45 injector leak. i need some diag help please - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

[email protected] · 08-14-2010, 02:50 PM

Im new here, i dont know much about nissans, im a ford tech so im having a little trouble with this obd1 nissan. well im working on a 1990 nissan 300zx na. It sat for three years and the customer wanted me to go thru it and get it running. so i did. replaced the master cyl, did some break work, changed all fluids and it fired up and runs great. well on the way to smog the check engine lite came on. i figured out how to get the code i think. even tho it said there should be an led blinking on the ecm i was not able to see that, but the check engine lite was blinking, so i figured i could pull the code from there. i got a 4 in the tens place and a 5 in the 1s place. so a 45. the def. for that code is a leaking injector. well i pulled plugs and only one looked slightly rich. and the car runs fine so im weary about it being a leaky injector. i ohmed the injectors out and they are all in spec. one is 9.8 ohms a little under but it is not the corresponding cyl with the rich plug so i dont know. now im pulling the intake to get to the fuel rail and see if any injector leaks. what a pain in the ass, not liking this z anymore haha. but i found a good tech write up on here on how to do it so that is making it easier. well my question is is there anything that can make this code come up except an injector. how does the computer know the injector is leaking, fuel pressure? or the o2 sensors? And being that it runs fine do you think it really is an injector? any info on this would be great. i searched and couldnt really find what i was looking for. thanks
--David

[email protected] · 08-14-2010, 02:54 PM

Ok, so i got the intake off, hooked the fuel rail up to the lines plugged stuff back in and turned the key to get fuel pres and test for leaks. the injectors are not leaking, i activated each one and they all work. i ohmed them all out and only one is a little below 10 ohms. the lower seals for the injectors to the lower intake are shot and one seems to have been leaking a little fuel out. could that be the cause of the code. i bought 6 injector seal kits and im gonna replace the seals on all of em and put it back together, hopefully it works. any info would be great. especially the computers stragity on how it sees an injector leak so i can see if anything else could cause this problem. im into it pretty far now so i hope i can get it fixed. thanks
--david

08-14-2010, 02:50 PM	#1
[email protected] Join Date: Aug 2010 Location: santa maria ca Age: 34 Posts: 4 Trader Rating: (0) Feedback Score: 0 reviews	90 300zx na code 45 injector leak. i need some diag help please Im new here, i dont know much about nissans, im a ford tech so im having a little trouble with this obd1 nissan. well im working on a 1990 nissan 300zx na. It sat for three years and the customer wanted me to go thru it and get it running. so i did. replaced the master cyl, did some break work, changed all fluids and it fired up and runs great. well on the way to smog the check engine lite came on. i figured out how to get the code i think. even tho it said there should be an led blinking on the ecm i was not able to see that, but the check engine lite was blinking, so i figured i could pull the code from there. i got a 4 in the tens place and a 5 in the 1s place. so a 45. the def. for that code is a leaking injector. well i pulled plugs and only one looked slightly rich. and the car runs fine so im weary about it being a leaky injector. i ohmed the injectors out and they are all in spec. one is 9.8 ohms a little under but it is not the corresponding cyl with the rich plug so i dont know. now im pulling the intake to get to the fuel rail and see if any injector leaks. what a pain in the ass, not liking this z anymore haha. but i found a good tech write up on here on how to do it so that is making it easier. well my question is is there anything that can make this code come up except an injector. how does the computer know the injector is leaking, fuel pressure? or the o2 sensors? And being that it runs fine do you think it really is an injector? any info on this would be great. i searched and couldnt really find what i was looking for. thanks --David

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08-14-2010, 02:54 PM	#2
[email protected] Join Date: Aug 2010 Location: santa maria ca Age: 34 Posts: 4 Trader Rating: (0) Feedback Score: 0 reviews	Ok, so i got the intake off, hooked the fuel rail up to the lines plugged stuff back in and turned the key to get fuel pres and test for leaks. the injectors are not leaking, i activated each one and they all work. i ohmed them all out and only one is a little below 10 ohms. the lower seals for the injectors to the lower intake are shot and one seems to have been leaking a little fuel out. could that be the cause of the code. i bought 6 injector seal kits and im gonna replace the seals on all of em and put it back together, hopefully it works. any info would be great. especially the computers stragity on how it sees an injector leak so i can see if anything else could cause this problem. im into it pretty far now so i hope i can get it fixed. thanks --david