Ok So my problem. I am getting 250KMS to 35 litres of fuel in my 1999 Sunfire GTX. The Engine Is a completely Stock 2200 SFI with a stock 5 speed transmission.
About the Car: 86,000 KMS i am the second owner, previous owner was a retired cop that bought it new in 2000. The Car Sat for 6 months before i bought it. It was stored in a heated garage.
Ok So parts that i've replaced: (can there be anything i haven't fixed????)
Plugs, Wires, Distribution packs, Injectors ( from a car with good gas mileage, never can be too sure) Thermostat, cooling sensor ( 2 wires on the antifreeze pipe) Air Filter, Fuel Filter, BRAND NEW fuel pump, OEM clutch (in case it was slipping i didn't know how to tell).
I also ran injector cleaner, fuel pump cleaner through the system.
There are absolutly no leaks, No kinked fuel lines. I only drive on the highway ( so mileage should be better right?)

Any Help Is Greatly Appreciated.

There is also No CELS on. forgot to mention and it seems i can't edit my post?

Try changing the primary o2 sensor. Thats all i can think of right now.

P.S. you can't edit your posts unless your a premium member.

So you are just throwing parts at it till it gets better?

I don't see it in there, but it sounds like an O2 sensor problem to me. I dunno, usually 02 sensors creep down into the 14 MPG range (you are around 17...)...air filter maybe?



"The Blue Bullet"

Hi,

Didn't see that you list you had the fuel pressure checked? There is a regulator that prevents excess fuel pressure. Too much pressure will cause an excessive amount of fuel to be sprayed each time the injection nozzle opens. Not unlike a house's watering hose. Low pressure at the tap and it will dribble out when you squeeze the nozzle lever. At high pressure the same opening duration will shoot a stream of water across the yard. Now imagine the liquid is $3 per gallon gasoline! This in turn can damage Oxygen Sensors (O2) and the catalytic convertor from unburned fuels being pushed out the exhaust. Oh, and destroy your fuel mileage!

Dave

david keevil wrote:Hi,

Didn't see that you list you had the fuel pressure checked? There is a regulator that prevents excess fuel pressure. Too much pressure will cause an excessive amount of fuel to be sprayed each time the injection nozzle opens. Not unlike a house's watering hose. Low pressure at the tap and it will dribble out when you squeeze the nozzle lever. At high pressure the same opening duration will shoot a stream of water across the yard. Now imagine the liquid is $3 per gallon gasoline! This in turn can damage Oxygen Sensors (O2) and the catalytic convertor from unburned fuels being pushed out the exhaust. Oh, and destroy your fuel mileage!

Dave

Where is this regulator located? i'm sure the o2 sensor should be good because i don't have a code, but i'll look in my haynes manual to see if there is a procedure for me to look at to test both o2 sensors.
Thanks.

OK well its been raining and i don't want to use my $450 tester out in the rain to check the o2 sensors, but they don't look that old ( hardly any dirt or grim or rust on them)
But i was looking through my repair manual and it shows the EGR (exhaust gas recirculation) being right beside the coils, Well I can't find mine. and the car hasn't been modded or anything its a stock car with a stock engine.

Now, some people i guess wonder why i put all them parts on, well the car needed most of them.
the fuel pump made a weird freaking noise when it primed ( mechanic said its going to leave me stranded soon)
the Distribution packs had cracks in them ( weird i thought but let moisture in and caused misfire). The injectors because i thought maybe they where not squirting right. thermostat well, i didn't know if it was original or not, and some cars are affected with bad gas mileage so i changed it with a dealer one( well i think, i had it delivered to a shop and it said GM on it...) and well the rest it just regular maintenance.
Right now the car drives OK... But if i can't figure this out i think i may have to move on to something else. Since i travel over 100kms a day each way and reliability is a +++(plus fuel mileage)
And is there somewhere else i should post this? like another forum just to see if they can help too? which would you recommend? i was recommended by a friend for this one, which seems excellent so far

I don't believe there is an EGR on the 2200, it was only on the 98 and older motors, although I could be wrong.

After a trip, feel the floor of the car around the center console. If the floor feels excessively warm then the catalytic convert is plugging up. Which will also cause poor mileage.

Spike700 wrote:I don't believe there is an EGR on the 2200, it was only on the 98 and older motors, although I could be wrong.

After a trip, feel the floor of the car around the center console. If the floor feels excessively warm then the catalytic convert is plugging up. Which will also cause poor mileage.

How Long would it take to make the floor warm? I'll be traveling about 100kms tomorrow so that should be enough right?
and the o2 sensor tested fine, in the range of what the book said.

So how do i know if the catalytic is plugged besides the floor being warm?

A lack of power is usually the first thing you feel while driving. I also seen and heard of poor exhaust flow coming out the tailpipe. Only other thing I can think of, what temperature is the engine running at? If its not warming up fully, it could be using more fuel than needed.

If you have access to a lazer temp tool, you can shoot it at the exhaust and check to see if the cat is clogged I believe. The temp of the exhaust should be hotter coming out of the cat than before going in. If its drastically cooler, than I think the cat is clogged.

If someone could confirm that, that would be great.

In my own experiences with plugged cats, the exhaust coming out the tail pipe will be far hotter. Hot enough to cause a serious burn.

Well power wise it seems fine, no bucking, or dragging or anything. i checked the color of the exhaust (to see if spots where darker then the other) and it looks the same from the front to the back.
I Don't know but i think i'll get a map sensor to try(apparently causes gas to either flood or lean out from what i've read), and also remove the Cat and put a test pipe in it.

the car wont run properly without the cat.

are you retarded /\/\/\ you do NOT need the cat. is only there to reduce emissions in areas that have emissions testing. plenty of people run catless with no problems

not going to test mileage problems very easy if the CEL is on because the rear O2 sensor is unhooked or reporting the wrong value.

Wojo wrote:are you retarded /\/\/\ you do NOT need the cat. is only there to reduce emissions in areas that have emissions testing. plenty of people run catless with no problems

Well Legally where i'm at i can have my car impounded and given hefty fines if caught.

Anyways. I Haven't got to driven the car very far yet to see if the mileage is better. Cut the cat off (don't worry there is NO cels on yet, doubt there will be... )and put a test pipe in there for the meantime. I have another map sensor i'm going to install after i take the car for a good long drive.
But i noticed something wierd today. the muffler is VERY VERY small and round (not straight through) compared to my old cavy's muffler ( like the old ones 2 times the size NO LIE) So yea Weird if you ask me. half tempted to put the bigger one on.
And Correct me if im wrong but the o2 sensors test values so if the primary reads lets say 599, and the second one reads 599 then that'll be okay right? That means no plugging so BY RIGHTS i could leave the test pipe on there for a million years and the o2 sensors wouldn't know the difference correct?

If the cat is working properly, the rear O2 sensor should read higher(voltage) than the front one. there should be less oxygen in the exhaust stream after the cat.

As far as the PCM, it expects the rear O2 to show less oxygen and it should kick on the cel although it may never do it.

I have no cat (was done before I owned it) and the rear o2 was cut off,not just unplugged.Dummy cut the wires.If I reset the CEL I can run a few days with no CEL but out of the blue it pops on and reads No input o2 sensor bank 1 sensor 2 or some crap like that.Runs ok but probably not the best.No money for it right now I have more serious issues but yeah you can drive without a cat or downstream o2 sensor.Probably not wise though.



<br>
98 Cav,2 door,5 speed,2.2L. I'll pull the stickers and repaint when I get around to it.Get off my nuts.Thanks and have a great day =]

Well No changes, i spent all last night trying to look up for the regulator thats plugged as mentioned in this thread. I'm sortof feeling the whole gallon of gas and a rag at the moment. this car is starting to drive me nuts especially when it doesn't work all the time now. went out this morning after the thundershowers all it did was wind over, no kicky. Had to get to work so i borrowed my roomates civic. At work ATM and called a tow truck to tow it to a shop to get it running. Figure the new fuel pump gave out( it too made a wierd noise yesterday) or a relay or fuse.

Anyways. Yesterday no difference with the cat off, gas mileage was still @!#$ty. i like the noise of the stock muffler though, nice HUM to it. map sensor is going to be changed when ever i get the car running again. boo ya. getting ready to look for a new car i think. spent almost 2500 on this car is 2 months and did most of the work myself.

fuses. didn't realize the window was down that night and well it popped a bunch of them. cars working again. map sensor changed(wow 2 8mm bolts and a plug, that was so easy for a change). took it for a drive and well, it revs excellent on the highway ( wierd, maybe because i didn't drive it for a while i don't know). gas mileage is the roughly the same. anyways i'm stumped about the regulator because i don't know where to look for it at. so another update i guess.

bumpidy with gas at 1 dollar a litre i need this fixed ASAP.if not im buying a new car with better freaking gas mileage and driving this sob of a god damn cliff. Can anybody shoot some ideas at me? The Catalatic converter is back on the car.

Hate to bump but help is now needed desperately. starting to get really expensive to drive now ( 1 tank a day...) new job :S

HI,

The fuel pressure regulator is in the fuel rail and regulates the pressure to the injectors. It doesn't "plug" up but it can go bad. Not sure about your motor but many are regulated by a vacuum line that comes off of a switch. Sometimes the vacuum line will go bad, or the regulator itself or the control. Get the fuel pressure checked, don't just start replacing parts. If the pressure is too high more fuel will be used when the injector clicks open and the injectors could even leak while not being told to fire.

Without the car in front of us no one can tell you what is wrong with it. Diagnosis via keyboard is spotty at best. Maybe your neighbors hate you and siphon fuel at night just to mess with you?

As you mentioned, you may be do best by selling this car and getting a car that is known to deliver high mileage such as a Yaris or similar subcompact if you are driving a lot. Some of the old Honda Civics give amazing mileage up in the 40's. (US MPG)

Driving technique affects mileage a lot, quick take offs from red lights and stop signs, uneven pedal pressure, etc. Also sustained speeds above 60 MPH (what is that 100 KPH??) always delivers worse fuel mileage. These two factors can significantly lower you mileage.

Simple mechanical things, dirty air filter, dirty engine oil, slipping clutch or auto trans, dragging brakes, low tire pressure, tires that have a high rolling resistance, carrying a lot of weight in the car, exteriors bolt on modifications such as roof racks and air dams, etc, etc, etc.

If your car checks out 100% mechanically sound, start looking at the factors that involve you the owner / driver and what changes you can make.

I can get 36 MPG out of my Pontiac Vibe that the EPA says will only give me 29 MPG, when I drive carefully. If I drive aggressively I'll only get 26 MPG on that same trip in the same car.

Dave

Thanks for the reply. OK so if i check the fuel pressure and it is on 40 psi then i should maybe replace the rail? ( i have a spare one off my wrecked car).

I know its a pain when people are trying to help over the internet, but when i take the car to the freaking dealership they say [quote:]well your driving it like a tard. These cars are the best thing for mileage blah blah blah. but honestly theres one red light on my drive to work, then its all highway driving for around 100 kms at 110km/h [posted speed limit...] then i exit an off ramp make 2 rights and I'm there. So you might say? well my driving characteristics. I usually shift it when the shift light comes on, usually before. The neighbors could be siphoning my fuel, they only problem with that is i park the car in a locked alarmed garage, so they'd have to be crazy NINJAS. but i think they'd be after something a little more valaubale then gas if that was the case.

I am actually looking at a new car ( to me) but my roommate has a 94(?) 'EG' model civic coupe for sale thats in excellent condition and such with great gas mileage so i don't know. or i might look for a new corolla but i don't know i kind of like the J's for some odd reason but with GM going bankrupt ( o they will be ) I'm leaning more towards company's who will guarantee my warranty

The car is Stock, no mods. NOTHING. has 195/60/R14 in CHARGER tires all around with 35psi in each tire ( i check regularly) now afriend told me that oil can slow the movement down causing more friction causing the engine to work harder so if i put better oil in it will it cause any difference?

And so you know, my last cavy got 38mpg on the highway (good considering 17" rims )

so yeah. another update.

Yea i think i found a big issue. Nice little smoke coming out from under the hood while driving through town getting some clothes and stuff, for some reason. Yea the car burnt pretty bad as in from the doors towards the front, inside and out. Um? appeared to be alternator wire shorted out against the metal bracket for the injectors and well thats all she wrote. The tow company said its a total loss i told them no @!#$. so basically 3g gone because of this pos. thank god i got ful insurance.

But Sadly, My J-body craze is over. i'm done with these brand of cars. Talking about it for a while i know but the decision is final. Anyways i changed the fuel rail right after my last post. STILL had no difference. So i hope this thread may be useful to some people who need assistance.

Right now i'm driving an 89 CRX (Honda civic hatch) I like it alot actually. Works great for 440,000 KMS HAHA. Cant kill it. Literally its been through hell and back and gets 600KMS TO A TANK.

Anyways Peace Out, Good luck with everyones cars. Obviously i never had luck AT ALL with them. Anybody wanna buy a custom car AHA good for racing most of the paint is even stripped ...