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hi! im new to this forum but i think i need some other opinions on this now.
my car has been running rich ever since i got it, it stinks really bad and i get horrible gas mileage, like 18 ive estimated. now i blew the engine and rebuilt and replaced it and i had this problem on both engines, so not the engine, i bought an o2 sensor FOR my car, the 4 wire one and put it in, i have put in new plugs and wires, installed a fuel air ratio guage correctly that allways reads rich except on deceleration which it leans out a little but if i kick it out of gear or touch the gas it goes all the way rich.
now this is where it gets weird, i disconnect my o2 sensor and theres no check engine light, and it runs the exact same, i tried to check codes but it gives me a vtec pressure switch code, like 22. i had been having problems with vtec also but ill worry about that later
its KILLING me on gas and it allways has since i got it, i think its a wiring problem? but its like the o2 sensor shouldnt exist, i disconnect it and it dosent throw a light or tell me something is wrong...
is there an alternative to the o2 sensor like a fuel pressure regulator? and if i did go that route would i run too lean in vtec?
its a 95 ex civic coupe d16z6 with intake, headers, and straight pipes... and i know straight pipes arent helping, but i know it will stink a bit but its horrible im embarrased to drive it
Last edited by Rawr51x; 10-19-2008 at 05:23 PM.
Reason: car info
Disconnect the out line from the FPR. Crank the car (also disengage the ignition system) if fuel starts coming out the outlet nipple then your FPR is fine. Next step disconnec the injector clips to your injectos one by one and see which one kinda helps the car run a lil when you pull it off. The one that shows this symptom is your problem. Now you have one of 2 options if this happens. Either your injector is stickin open or your computer has a fault maybe it's stuck in open loop cycle (no one to really tell without bench testin he injectors). Normally one would just suspect the injector and 4 out of 5 times it is the injector. But it's happened a few times at my shop where it urned out to be the computer.
PS. if you unplug the O2 and it doesn't immediatly turn on the CEL don't be concerned. It's an OBD1 car sometimes it takes them a while before they realize something is wrong. And OBD1 codes are not specific so it might just tell you something like misfire or something instead of actually saying O2 is bad.
thanks so much for your reply, but i changed out the injectors with ones i had in another intake manifold, and the ones i took out were brand new looking, and i think i changed out the fuel pressure regulator also with an extra i had on the same intake manifold, so unless those are bad too, maybe its my computer? ill try what you just told me, but i disneguage the distributer so no spark and then try to crank it with only 1 injector unplugged and the other 3 plugged in, that will cause a knock right? and what am i supposed to look for when i unplug it, for it to run leaner? what do you mean by better?
and when i test the injectors, leave te ignition system on? because if its off how will i test if it runs because it wont turn over it will just crank. im sorry im just confused as to what to do
No i only wanted you to disengage the ignition to test for fuel coming out of the fpr. If you want to test the injector just unplug it till it runs less misfiriery i guess. Does it seem to misfire right now? So if someone has an extra ECU around you and swap it out and see what happens. This is the exact same problem we had with an altima at my shop.