CIVIC VX D15Z1 ENGINE FUEL MPG + IDLE problem !!

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CIVIC VX D15Z1 ENGINE FUEL MPG + IDLE problem !!

By KRYSTED9354
- Sat Feb 09, 2008 2:02 am #41521 If anyone helps me out i will paypal them 10$ or send them 49 superstreet magazines :thumb:

my problem is this i have notice a drop on full tank i use to do 350-400 now i do 200 ,also my car idles at around 500 and jumps to 700 and back on neutrol that is ! ALSO EXAMPLE im in 4th gear and i slow down all the suden my car will quietly sputter and lag like its getting over flown with gas, 3 problems drop in mpg,bit slower acceleration and most ofd all on low RPM my car studders , also when i changed my cat i notice in my exhaust system a fresh smell of gas soit looks like its not burning all of it up , can it be bad air/fuel mixtur or to lean or bad injectors or HELP !!! GOT MNY P/PAL ready so let me in on my problem :hehe:
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By KRYSTED9354
- Sat Feb 09, 2008 2:59 am #41527 ANYONE ?
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By Apexracing
- Sun Feb 10, 2008 4:01 pm #41678 first of all what do you got isntalled as far as after markets? second of all check your throttle body, and intake manifold gaskets for leaks using a spray bottle with water just mist around the gaskets while running the engine and look for bubbles. also perhaps the car isn't fireing correctly have the distributer checked/ do a tune up plugs wires cap/rotor. or have the coil pack looked at if it is a newer engine. maybe a bad injector or needs cleaning. maybe just stretching on this one a bent intake/exaust valve. and is the check engine light on? check the ecu under the passenger side carpet should be just under the glove box, with the car running check the lcd status light see if it's blinking if it is it mean you have an error code check the number of blinks with a haynes manual or ect to find the specific problem. let me/ us know.
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By KRYSTED9354
- Sun Feb 10, 2008 4:11 pm #41682 k thanks yeah i have intake exhaust system and no check engine light ill check to ecu what color light ?? and i did a tune up new plugs wires ETC and i know the valves are ok , jst mabey because my fuel relay is blocked and running on i need to replace that and also can it be because my exhaust sensor 02 is before the catalytic converter because of my echaust systme ?? thanks
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By KRYSTED9354
- Sun Feb 10, 2008 4:41 pm #41684 OK thyou so much i will have to try it out , i know i have to switch my sensor after at,change my fuel relay, check injectors and reset fuel system i was told how do u do that ?? i was told u take out some fuze and it resets the fuel system if there was an error ??

By DannyCraQ
- Sun Feb 10, 2008 5:13 pm #41689 make sur ethe hamster didnt fall off the wheel, if so, help the lil guy back on :thumb:


nah jk, yea id say its either the o2 sensor like apex said


hope you get all that fixed
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By KRYSTED9354
- Sun Feb 10, 2008 9:52 pm #41726 to do the ecu test do i have to have the engine running or just turn the key ???
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By Apexracing
- Sun Feb 10, 2008 10:57 pm #41730 running
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By KRYSTED9354
- Tue Feb 12, 2008 5:33 pm #41987 doesnt work no lights turn on and the hynes book states to just turn to on position ? :?
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By Apexracing
- Tue Feb 12, 2008 6:07 pm #41990 well then i would say if you followed all of the directions correctly and no light came on that you don't have any error codes recorded. so i ask have you checked the distributer/cap and rotor out? the idle jumping sounds like a vacum leak though does the idle just bounce up and down when left running? is it a concistant jump in idle? Have you checked gaskets for an air leak? can you post a small video of the car running so i/we can hear the symptoms? just need some more info because the problem is pretty broad right now. could also be a fuel problem if the injectors arn't pulsing/spraying right it may have that effect, maybe try another ecu?
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By KRYSTED9354
- Tue Feb 12, 2008 6:19 pm #41994 ok here is what i know it looks like the injectors are faulty-spraign to much because on a cold start the engine consumes more gas and car runs PERFECT !! but when warm and going like 80MPH and when i slow down it kind of lags up like it be getting drowned also my main relay doesnt work it only works when i bridge the 5-7 which means i think it means faulty soldering , i have heard its common problem, also the idleing is only when car get warmed up the it will just idle at like 300 when running like to day at a red light it went to 300 and lagged and stopped so i had to turn up the heat so the rpm's would go up or rev it , let m kenow what u know from my info, here also i checkedthe pc valve and replaced it
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By KRYSTED9354
- Tue Feb 12, 2008 6:20 pm #41995 is it possibole for ecu to break ?? and the main relay thing i have read that they have bad soldering spots that brake when they heat up , mainly in wintewr because of the heater !
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By Apexracing
- Tue Feb 12, 2008 6:36 pm #42002 i have had to replace other ecus but not a honda so idk i am assuming here that any thing electronic can and will go bad eventualy. but why did you have to turn the heat up to smooth the idle out that doesn't sound right. there is coolant running through the intake manifold comming from the head. the jet in the head has a gasket that is integrated into the intake manifold gasket, maybe your car could be drowning in coolant? is it leaking burning or loosing any coolant? and white vapors coming from the exaust?
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By KRYSTED9354
- Tue Feb 12, 2008 9:04 pm #42014 no no coolant leaking or nothing just burns a tiny bit of oil ,
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