joelmatt89

Okay so I have pretty much come to the end of the road in testing every possible thing i can think of. Car is a 93 ex coupe w/b16 swap and no cels, since i got it I have been getting 12-15mpg. The previous owner did the swap right before i got it and hadn't even driven it more than twice. I'll give you a list of things I have tried, new o2 sensor, tried two different ecus, spark is perfect... I compared it to my co-worker who just had her wires, rotor and cap replaced, fuel filter,tps sensor is good, iacv and fitv have been cleaned, injectors are all clicking and none are leaking, all wheels turn freely with the car on jacks, cat is not clogged i can see daylight through it when i took it out, all four cylinders read about 190psi +-5 after the engine has been warmed up, Car doesn't consume any fluids. The only thing I haven't checked is fuel pressure so I plan on doing that this weekend. The plugs do get bad after about a month from the rich mixture, and the exhaust smells and looks rich so i don't think it is a leak in the fuel lines or something.

Like I said I will pay whoever can solve this 50 through paypal, if that goes against some sort of rules on this site sorry but I am desperate. I am really counting on h-t for this one, the last thing I want to do is take it to a shop so they can screw me over.

alexsi

It could be the ECT (engine coolant temperature sensor). If its reading as if it's cold all the time, it would cause it to run rich.

RH2008

need more info, how was this info 12-15mpg being calculated, and what is your driving style, even in a honda u can get **** poor mpg if u drive foot to the floor all day

pvt_awol

I did a GSR swap in a '98 civic that did the same thing. It seemed to run well, had good power, got lousy mileage.

in the end, it ended up being wiring in the engine bay that got swapped around somehow. didn't even throw a code.

raidacaipo

easy to solve...
problems:
low gas mileage, running rich, seems to me like no one upgrade the fuel pressure regulator to an adjustable one.. I bet you have an aftermarket fuel pump don't you? also take out one of your spark plugs and check the tip.. I bet its black as hell..

solution: get an adjustable fuel pressure regulator with a psi gauge and see where your psi is at.. it shouldnt be higher than 39-40psi unless your running big injectors, cams, and high compression pistons.. if all else fails then bring it to a shop to get it tuned..

Another solution is to check ignition timing.... make sure its at btdc 16 degrees or if you advanced the timing btdc 18 degrees.. this means having an adjustable timing light and checking it..

now I want $50 so you can send it to my paypal verified address at raidacaipo@yahoo.com :]

EL Vap133

Are you running an OBD0 B16?

speedooo

get an a/f gauge and an adjustabe reguslator with a pressure gauge...mess with the regulator until you get the gauge in the green.

the diaphram in the regulator could be ripped...it happened in my jeep

VandA_hondalovers

i know you probibly already checked but is the ecu the right one for that motor and try checking air flow and the position of the distributor and my brother said to check the fuel filter between the motor models like the filter for the stock motor for that car and the si motor in it now and see if they are different capacities and he asked if you have a fuel pressure regulator and also unplug and clean all the wire harness connecters and see what happens im gonna try to ask around for you and see what else it could be to cause something like that.....................

jasons9594

lol theres no way its the fpr u do not need a adj. one and nor should u have a resister box in a b16 swapped stock injector swap!if it was me i would warm up the car put a jumper wire in the cel harness check timing and if thats good i would check to see if ur cat is plugged...o and no paypal needed....just trying to help another honda owner out..

96 EX

I just replaced the PCV valve in my car and it increased my mileage a whole hell of alot. Worth a shot especially for only $2.50. It helped my mileage, response, and quit throwing oil in my intake mani/head.

raidacaipo

if he has a resister box in a b16 swap then it must mean he might be using aftermarket obd1 injectors that are unsaturated.. yeah people actually use obd1 unsaturated injectors therefore it requires a resistor box. And that could be the problem if his injectors are too big for his application. And to say you dont need to adjust the fpr? hes running rich and you say he doesnt need to adjust his fpr? okay smart guy...
like I state above. Adjust the fpr IF you have an aftermarket fuel pump or check ignition timing.. The bigger injectors could also be the reason for massive fuel consumption. Try stock b16a injectors and like someone stated before swap for the stock ecu for the right application.

ej1bmx

Yeah, if he has an aftermarket fuel pump, I am guessing it is dumping too much in if he has no fpr. My friends was eating gas after upgrading fuel pumps when his stock one went out.

Unseen Racer

raidacaipo got my $50

joelmatt89

Okay i will look into this

No I have kept it under 3k all the time I calculated by filling it up at a pump till it clicked then resest my trip meter then when i get to 1/4 tank fill it up at same pump when it clicks and do the math.

I have checked most the wiring but I will check all that again, what do you recommend just check continuity to the ecu from all the sensors and check for grounds/voltage where necessary
Ha your pretty sure of yourself well the plugs are black after about a month but for the first two weeks they look great like coffee with creamer! the timing is right at 16 and no it's a stock fuel pump.
the engine is from a 99si (obdII)but i am running obdI which is why I need the resistor box

Okay thanks ill look into that
ecu is right, it's been chipped for the motor, and i know the chip is good because a bone stock p30 in it got the same mileage. It is the fuel filter for the car ie. for a d series, but i asked on here and they said that was fine

Well it's an obd1 ecu with stock obdII injectors from the b16, timing is good already checked the cat it's clean can easily see daylight through it.

joelmatt89

the purge control system was removed when the engine was swapped. But from what i know that doesn't affect mileage it just pisses off mother nature

Now that i think about it i should check maybe it does have an aftermarket fuel pump

Wow money sure does talk I have posted this same post like four times and got maybe five replies!

killahatch

check your IAT sensor. if the plug to the IAT sensor and the purge were switched around it will give horrible gas mileage. i had abuot 20 mpg on my stock b20 but when i switched the plugs back to normal and bought a new IAT sensor im getting about 30 mpg.

if you take out your IAT sensor and the prong is melted/burned then i think the plug was switched around.

worth a try.

sde780

Tires? Run some Seafoam?

joelmatt89

well i was throwing a code for that when i got it cause the plug wasn't getting good contact with the prongs but i fixed that and tested the iat it has the right resistance for the temps i tested it at.

The tires are fully inflated if thats what your saying. I don't really want to run seafoam through it even if that helps my mileage it
still isn't fixing the source.

Please keep givin me ideas as soon as i have time prlly this sunday i will check every single one. You have no clue how bad I want to fix this problem

speedooo

get another fpr...the diaphram could be ripped. and dont get a blox unit...get a complete new fpr

freakasis

i put my money on it having to do with the IAT sensor....what year b16 is it? where is the temp sensor located?

raidacaipo

Trust me.. you bought that car from someone else who did the swap.. I bet he has a walbro fuel pump.. that thing will bring your fuel psi with a stock fuel pressure regulator to at least 60psi.. which is really high and is causing your car to run rich and your spark plugs tips are black as hell.. my friends car did the exact same thing.. he installed a walbro 250 fuel pump and same symptoms as your post and he has a stock fuel pressure regulator, until we bought an adjustable blox fuel pressure regulator with a psi gauge.. we adjusted it to 39-40psi and it felt smoother and saved more gas!

Another thing to look at is the fuel injectors.. since you have a resistor box, it may mean that the first owner swapped out the injectors with bigger injectors like a jdm h22a which is 345cc unsaturated..

Last thing to look at is the ECU.. check to see if its the proper ecu for your application.. What kind of ECU is it? I would like to know..

And your timing is btdc 16 degrees so we know its not the ignition timing anymore.. it has to be either:
wrong ecu for application
aftermarket fuel pump without an adjustable fuel pressure regulator (not the stock one)
Injectors are too big for application

and if your not getting any CEL for any sensors, then its most likely not a IAT or IACV or TPS or MAP sensor problem.. I ran my gsr with a burnt melted IAT for years and it ran fine without any problems.. your sensors are pretty dam strong

trustdestruction

So about this $50 thing... if you try more than one suggestion and your problem is fixed it is impossible to know whose suggestion worked.

Resistor box is suppose to be 6 ohms like what you measured. I pulled one off a junked car and had to test it before selling it so I used the 88-91 factory service manual and it said 6 ohms.


is this primarily highway (55mph and over) or city driving? that would help us have a better idea of how worse than normal the gas mileage is.


are you getting any detonation? Are you running premium (91+) like the B16A2 calls for?

Former User

Joel, if the fuel pump or fuel pressure regulator turns out to be the cause of your low mileage, I demand a cut of the payment (50-cents seems fair) as I have suggested several times that you measure the fuel pressure and test the regulator.

xiongtoua1990

it can also be the head gasket last time i crack i robs gas like crazy.

raidacaipo

Wheres my $50?

http://www.youtube.com/watch?v=EuAVgWJ28Hw