So i took my car to get smogged yesterday and my readings were very unsatisfactory. ie very high hc and co
so i ran my ecu and pulled just one code 76. i looked in the faqs at 240sx.org and found that this is for the fuel injection system. i searched further here and couldnt find anything to helpe me out. anyone have any suggestions? my 95 is running very rich hence the failed emissions! thanks for your time!
Ecu Code 76
i think you have 2 problems here your numbers indicate a very very rich condition and also your co2 indicates ineffecent burning the co2 is very representative of cat efficency. that number should be up around 14% are you sure you dont have your co2 and your co swapped in your post? Shoot me now btw. I didnt get a chance to look up your code today. got wrapped up in rewiring a 300zx convertable and forgot about it by the time i was done. I will look tomorrow though for sure. I think that code might be injector leak though because of your readings on co and hc. be aware though your NOx is low because the fuel is so rich. that will go up once you fix your uel mixture problem. NOx is created by heat and pressure. but with so much fuel in the combustion chamber it is to cool to create NOx. just thought you should know that incase it fails for that after you fix the fuel problem. I would check your fuel regulator for leak into vaccum line and also do a leak down check on injectors as well.
you need the gauge to do an accurate leak down check. when you get the gauge on there turn the key to the on position and let the pressure build. once it builds up shut the key off or wait for the pump to deactivate and watch the gauge if it drops more then 10 psi in 10mins you have leak down somewhere in the system. now you need to isolate where the loss is. do it again bring the pressure up. and pinch the feed line between you fuel filter and the gauge. if it still drops you now know it is either the injectors or the fp regulator. If your reg is leaking down it wont be the cause of your failure just so you know. if the reg is bleeding off do the test again and pinch off the return line. if at this point your are pinching off the supply line and the return line you are meausreing the pressure in the rail only if it bleeds down you have an injector leaking. now if all that checks good and your regulator isnt passing fuel into its vaccum line you have a serious fuel control problem. here are a few things off the top of my head coolant temp sensor,O2 sensor, air flow meter these are the big three fuel control devices. this excessive fuel condition has most likely destroyed the cat or at least damaged it. once you get it fixed you may find you still wont pass due to that cat being bad.
ok, i found that right before i had done my last test ^ i didnt tighten one of the fasteners enough.
so i performed the first one again with no lines clamped, and i only lost about 6 psi in 10 min...
i also left the car running for about 10 min occasionally taching her up to about 2krpm. and my code 76 is gone. all i get now is 55's and i know that that means everything is fine.
could it have been that a connection was loose? im a little perplexed now. what do you think nistech?
oh and where in norcal are you?
so i performed the first one again with no lines clamped, and i only lost about 6 psi in 10 min...
i also left the car running for about 10 min occasionally taching her up to about 2krpm. and my code 76 is gone. all i get now is 55's and i know that that means everything is fine.
could it have been that a connection was loose? im a little perplexed now. what do you think nistech?
oh and where in norcal are you?
37 psi is not bad. and since your code went away after your reconnected what ever you connected I would say you fixed that part. when you checked your injectors for leaking proir to this test was it before or after the smog. if it was after it is possible you had a oring not sealing properly and fuel got into the cylinder causeing the rich run condition then after removing them to inspect ,when you reinstalled them the seal sat down properly resealing the leak. what connector was it you did not reinstall properly?
I am in the sacramento area. about 30 miles south of it actually
I am in the sacramento area. about 30 miles south of it actually
it was the fittings that held the fuel pressure gauge onto the rubber fuel feeder line, just didnt tighten that on enough to hold a seal i was loosing a small stream of fuel which was causing me to lose more than 10 psi in 10 min. im gonna drive her for 1 or 2 days and see if i can get that code again, but if not then im gonna go to smog and see if that was it. im in citrus heights. cool! ill keep ya posted man, thanks for all the help.
its about 10 min from roseville. i live right off of I 80 on the antelope exit.
so i went to the smog station today and everything has seemed to be ok. as you said my co rose to about 14 %
my hc dropped to around 136 for the 15mph test and 53 for the 25!
my co is at about .96 for the 15 and .20 for the 25! everything is gravy!!!
so i figured as you would say i just about fried my cat so i am in the process of acquiring a new one. do you have any recommendations for shops around town? i know the 2nd cat is a dummy so i should be replacing the 1st one that comes off the exhaust mani correct?
i just wanted to say thank you for all your help and knowledge. i know for a fact that you saved me nearly 200+ dollars in diagnostic fees. THANK YOU
so i went to the smog station today and everything has seemed to be ok. as you said my co rose to about 14 %
my hc dropped to around 136 for the 15mph test and 53 for the 25!
my co is at about .96 for the 15 and .20 for the 25! everything is gravy!!!
so i figured as you would say i just about fried my cat so i am in the process of acquiring a new one. do you have any recommendations for shops around town? i know the 2nd cat is a dummy so i should be replacing the 1st one that comes off the exhaust mani correct?
i just wanted to say thank you for all your help and knowledge. i know for a fact that you saved me nearly 200+ dollars in diagnostic fees. THANK YOU
is it still failing? your 50/15 readings are a little high. but your 25/25 readings are ok not the best but acceptable considering. looking at the differences I would almost say your cat was not completly to operating temp during the 50/15 portion. what are the maximum and average numbers for HC CO and NOx the average is average for other 95 240's tested throughout the state. Its a good way to judge your engine efficency.