joelmatt89

So I could tell that my mpg was pretty bad. So I filled up and stopped exactly when the pump clicked and then reset my odometer the next time i filled up my odometer read 160.2 miles and it took 10.137 gallons that works out to 15.8mpg. I drove like a granny for the entire week it never got over 3k most of it was city but still that seems really bad my cj7 gets that kinda mileage in the same driving with a straight 6. The car is a 93 coupe with a b16 and a p28 ecu chipped right know. It hasn't been tuned yet I know that could change alot but it still seems like it shouldn't be that bad. Please don't tell me to get it tuned, I would but the only place in my area says they start at $420 and i don't have that much to spend right now. I am sure that there is something other than just a tune causing this kind of mpg. I have changed the fuel filter, ran injector cleaner, and replaced the plugs, in the past month since i got it. The only other thing i can think of is the o2 sensor. I don't think the one on there is oem., i think it is a bosch. What should i look for when getting a new one ie. are there any specific specs is there a big difference between different brands of o2 sensors when i searched i wasn't sure if i should be looking for one for the engine or car or what or if it even matters. Thanks for your help.

sde780

I have a Bosh o2 sensor too and am getting horrible gas mileage. 22 mpg in a stock y7 with 50k on it.

check your tires, brakes for dragging, maybe bad fuel?

joelmatt89

its good fuel it has been through two tanks since i started driving it regularly. all the tires are at 40 psi. and i have had it on jacks and all the wheels spin freely so i don't think there are any brakes dragging. Do you think it could be possible that a bad o2 sensor could cause gas mileage to be that bad but not throw a cel.

689R

lambda sensor

sde780

Dunno, I was getting 28 in the city no matter what, suddenly the o2 sensor failed and **** dropped to 22 mpg. Then I bought a Bosch one, took care of the CEL but gas mileage never went up

Former User

Do some highway/freeway driving for comparison.

Are there any performance or idle issues with the engine? Are there any intake air or vacuum leaks? Have you measured the fuel pressure? Is the fuel pressure regulator working properly? Is the ignition timing set to spec? Are the plug wires, distributor cap, and rotor new? Have you inspected them? Are the valve clearances set to spec?

b16racereg6

iTrader: (2)

do u have the vacume hooked up to the map??? that could do it..

joelmatt89

hmm i dunno about the vacuum hooked up to the map ill check that, yes ron there is a bit of idle troubles when it is idling really cold it is all over the place sometimes i think it is a vacuum problem because i cleaned the fitv and iacv really well. Also i thought that it should die if i cover the intake. I tried it when it was warmed up and when it is cold and no matter how long i hold my hand over the intake the engine doesn't even hesitate. It seems like it goes away though as it warms up could this be from expansion as it warms up. I tried spraying carb cleaner over everywhere on the intake but i couldn't find a thing. Other then that the engine feels fine. I haven't checked fuel pressure i think ill get a gauge at harbor freight and do that sometime soon i saw they have one for ten bucks and my oil pressure gauge i got from there worked really well.

How do i know if the ignition timing is set to spec i haven't really inspected the things you mention i mean the wires look fine and the spark is strong. Is there anything i should look for in particular when inspecting the rotor and dizzy other than like buildup or something like that? I havent checked valve clearance wouldn't i need special tools for that? If i take off the valve cover is it necessary to replace the gasket and bolts everytime?

lsvtecturbosol

In all honesty it is probably your tune. I ran my car with a b16 and in my 99 SI I got 19mpg on a basemap tune for a stock b16. No intake or exhaust even. COMPLETELY stock. I got my hands on a P2T (stock ecu) I instantly got 42mpg.

these are highway miles also.

lsvtecturbosol

I am sure there may be other things that are causing bad mpg in your case and everyhting everyone else is telling you could cause it but I am just putting in my personal experience with non tuned ecu's

joelmatt89

Hmm thats nice to know does anyone have any experience with this from a ecu chipped by phearable.net, ill send john an e mail and ask him if this is normal. But like I said i really want to find a way to not spend more 400 for a tune also I am pretty sure i have a vacuum leak there is now way I am going to pay someone to tune my car when there are things like that wrong. I would like to get it running as good as i possibly can before i spend that much money on a tune.

lsvtecturbosol

where arey ou located? I got my tune for my turbo for 200 on a dyno tune. 400 seems steep just for a tune unless you have a lot done to your car that we aren't hearing about.

joelmatt89

northwest ohio, the place that is telling me that is Pure Tuning. I have heard they are really good from people on my local forum which is why they are so expensive. If anyone knows of a place in ohio or even the midwest that is cheap enough to make it worth my drive please tell me because i like saving money and a little road trip never hurt anyone. There isn't too much done on the car, intake mani, short ram, header, apexi ws2. gsr cams, and some other little things.

lsvtecturbosol

Well I am in va and all the shops I have here only charge 2-300 and almost all of their tunes I have seen are awesome. Sorry they aren't close enough but keep looking because 400 is pretty steep.

dohcdelsol

read your spark plugs. you probablly are running very rich and dumping fuel. what color is your exhaust fumes? have a blueish tint to it?

could be that the chipped ecu isnt correct and they messed up. honestly you gotta save up and get that baby tuned. bite the bullet man. i know what its like to be strapped for cash and need something done. ive just about starved myself trying to save for a cbr and im finally at that point. you sacrifice now and it will pay off later.

joelmatt89

the spark plugs look perfect very clean with a little brown tint like it should be the exhaust looks fine. Although the carbon is building up in my exhaust fast like if i clean it after a day of driving it is black on the inside. Yeah the thing is i am not really strapped for cash i am just prlly the biggest tight wad you will ever meet. I don't have a job right now and I don't like spending money when i am not making money which is why i want to wait about a month when i will have my seasonal summer job again. I know it prlly sounds so stupid but its just the way i am. But in the mean time i want to get it running as good as i possibly can before i get it tuned. I guess i should probably start a thread looking for dyno tunes and prices in the midwest I would be willing to drive three hours or so if the price was right. I know what you mean though about starving yourself i feel bad about spending alot of money on this car so i haven't eaten out since i got it ha. Its not like i won't spend money when i need to or for things i want its that I just don't like wasting money. But i like the cbr goal, i got an r6 last fall can't wait for it to warm up.

joelmatt89

Can you guys help me with the things he mentioned I have found ron is right most the time so i would like to check what he mentioned. Specifically how do i check ignition timing, what should i look for in the dizzy and rotor, and also how do i check valve clearance

dohcdelsol

check up in the FI and all motor forums. the FI forum has a link in the FAQs to tuners and such. r6 huh? me jealous. i was gunna go gsxr but i felt to leaned over on them. and the r6 is like the most race orianted bike you can get from the factory. im not at that point yet. i just feel extremely comfy on the f4i.

you will need a timing light to check the ignition timing.

lee0149

i heard phearable.net does a good job with base maps and dont charge to much for them either. I assume that it would be better with a chip and getting stock b16 map. I think there a obd1 b16 ecu too.

joelmatt89

I am confused what are you saying could you clarify that for me, my ecu is already chipped by phearable.net are you saying i should do something different?

But okay yeah i have a timing light. Oh yeah thanks for the tip about the fi forum. Yeah to tell you the truth i know i am on a honda forum but as far as bikes go from the people i know that service bikes and have ridden like all the major brands they recommend either gixxers or yamahas. But as long as you get a yamaha, suzuki, or honda you will be fine in terms of maintenance. I don't know, i just think the cbrs are a little overpriced. But right know is the perfect time to buy a bike because of the economy and since were still in winter.

lee0149

opps i didnt read the part you saying you got the ecu chipped by phearable.net. Just wondering did you ask them to put a stock b16 base map on the chip?

joelmatt89

no i just asked him to chip it how he thought it should be with my engine mods

joelmatt89

well phearable.net replied to my email he said that, that kind of mileage is not normal and there is somethin else causing it he recommended checking the iat sensor he said sometimes if you plug it in wrong you can fry it and it won't throw a cel.

newtron63h

im gonna suggest this. if you are going to harbor frieght, get a vacuum gauge. take the line off the manifold going to the brake booster, install the gauge line on the manifold. you should be reading between 17-22 "Hg(inches of mercury) at idle, if its BELOW this, you have a vacuum leak. also watch the needle, if its bouncing around while idling, especially in a very rhythmic way. you have internal issues.

i would say definitely check your MAP, TPS, O2, cap, rotor. dont worry about ignition timing, its elec controlled so it does its own thing.

does it seem low on power? what doesnt make any sense is that you say your plugs look good. if you were rich, you would definitely notice, if you were lean you would definitely notice. hmmmmmmmmm. very confusing

niceprelude

my 92 civic dx get 170 a tank with d15b7 engine,i think is the o2 sensor,but i haVE NOT CHANGE IT YET.