Running Lean, nearly stock, wtf.
 

I have a 1996 B18B1 in my 1992 Civic CX hatch.

Intake, and high-flow cat, and 2.25 cat-back exhaust.

Stock header, stock motor.

I just got my wide-band installed, and for a while now I've noticed that the car 'breaks up' a little at about 5700RPM untill redline. (wide band is just behind my ebay high flow cat, so its basically just a test pipe and has no affect on the wide band)

So I finally did some runs with the wide-band and found out my car is leaning the piss out at 5700RPM *pegs my wide-band at 16.8*

Ideas? Solutions?

Stock CX fuel pump with 110K on it, motor should only have like 74K on it.

Re: Running Lean, nearly stock, wtf.
 

A high-flow cat is still a cat, install your wideband before it for accurate readings.

Re: Running Lean, nearly stock, wtf.
 

There is NO material in exhaust path of the pipe, its nothing but a resonator.

Regardless, a 16.8 spike (while the car is loosing power) is more than just a coincidence.

Re: Running Lean, nearly stock, wtf.
 

Why don't they just call it a test pipe then?

Anyways, the lean condition is most likely being caused by the ignition breakup. The unburned oxygen in the exhaust will cause the wideband to display lean. Fix the ignition problem and your AFR should get closer to where you want it.

Re: Running Lean, nearly stock, wtf.
 

when I say 'breaking up' I don't exactly mean its the ignition, I just feel like its loosing power up top. I apologize if i didn't explain that well enough.

Re: Running Lean, nearly stock, wtf.
 

do a tune up on that ------- thing. cap, rotor, stock plugs, stock wires. How is it in the rest of the rpm range? is it the ls obd1 ecu? is it chiped? need more info.

Re: Running Lean, nearly stock, wtf.
 

Stock.

Motor is a 96, Car is a 92 (therefore converting the motor to OBD1 through use of stock wiring)

OBD1 PR4 ECU, Not chipped.

Rest of the RPM's it pulls like a raped ape, Spins into second with P205's on it.

Re: Running Lean, nearly stock, wtf.
 

sounds like it needs a tune up to me

Re: Running Lean, nearly stock, wtf.
 

I read a few articles stating that the CX fuel pump doesn't provide adequate flow for the B18.

Re: Running Lean, nearly stock, wtf.
 

let me guess never changed your fuel filter.

Re: Running Lean, nearly stock, wtf.
 

under hood fuel filter got replaced with a brand new integra one during the swap, in-take fuel filter I have not touched.

Re: Running Lean, nearly stock, wtf.
 

how are your afr's the rest of the time?

Re: Running Lean, nearly stock, wtf.
 

Cruising its in the low-mid 14's, every once in a while jumps over to lean (I've been told thats normal)

Idle is in mid 14's, every once in a while jumps over to lean (again, I've been told thats correct), WOT below 5700RPM is a steady 13.8-14.0 in any gear.

Re: Running Lean, nearly stock, wtf.
 

i guess i have a hard time believe that it could not keep up with only 100k on it and not really need to much more fuel but i guess the logic is there. walboro time or find someone who bought a walboro and is selling a cheap stocker.... like me :6 i have a fuel pump out of my 95 EX coupe

Re: Running Lean, nearly stock, wtf.
 

Yea, I ended up ordering a Walbro 255 today along with a B+M FPR and a VAFC....

Waiting to hear back from a member on these boards about some 550cc RC's that I want.

Re: Running Lean, nearly stock, wtf.
 

I just looked up the fuel pump on partsamerica and theat the 92 cx pump is the same as the 94-01 tegs....

Re: Running Lean, nearly stock, wtf.
 

yes, a NEW pump may be the same part, but my stocker may be a different part number than the integra.

Kinda like how the D16Z6 headgasket and the D16Y8 headgasket are now the same part and part number because they both work for the same application, but one was different from the other back when they came out.

Re: Running Lean, nearly stock, wtf.
 

damnit you shoulda bought my pump then id have an extra 10 bucks for some pizza tonight

Re: Running Lean, nearly stock, wtf.
 

I’m not very good at this stuff but is you have chanced your exhaust system. You are now flowing more air into your engine. You are using a stock ecm It dose not know about the change and is still using the same fuel maps. So same fuel + more air = lean. At lower rpms, cursing the system is using short/long term fuel trim and trimming you to 14.7 ish.

I can also see a misfire causing a lean condition. Ok I will probably get burned now by the og's.

Re: Running Lean, nearly stock, wtf.
 

Header is still stock, the rest is 2.25 piping.

the intake should have NO effect on how lean/rich I'm running since honda's are MAP cars, the ECU should be taking care of it.

Re: Running Lean, nearly stock, wtf.
 

wiht mods like that the computer should be able to compensate for the very minimal amount of air flow that is increased

Re: Running Lean, nearly stock, wtf.
 

thats what i figured too:

Question,

one of the bolts holding my 'test pipe' to my header is MIA, but the flange isn't really loose at all, if there is a small leak there could this be causing a problem?

Re: Running Lean, nearly stock, wtf.
 

The turbo toronado had an exhaust leak before the o2 sensor that fucked my A/F ratio. Let us know what happens when you get the new pump put in.

Re: Running Lean, nearly stock, wtf.
 

uhh yea, think about it, your motor sucks in air, then simply stated, burns the oxygen out of it. so what is comming out your exhaust is oxygen deprived. a leak of air before the wideband will allow oxygen rich (compared to the exhaust gases) gases in the stream. I would imagine that since faster moving air creates a lower pressure, that why it 'breaks up' at high rpm is that at high rpm you are creating a faster flow thru your exhaust. thus a small leak would be more apt to let more air in.

Re: Running Lean, nearly stock, wtf.
 

not that i think the intake is your problem, but at wot how would a MAP car be able to compensate for more air? It still sees the same pressure (zero) so how would it add fuel. A MAF ecu could, but not a MAP imho.

Re: Running Lean, nearly stock, wtf.
 

compensates for more air by reading the o2

Re: Running Lean, nearly stock, wtf.
 

bleh...im too used to not running an o2 i forget that people still have them lol. Oh well, next time ill think before i post in EM.

wait, but at WOT it doesnt run in closed loop so maybe im half right?

Re: Running Lean, nearly stock, wtf.
 

I guess all i had meant to say was that "I know a honda ECU can compensate for a basic intake without leaning out up top"

I will throw on new hardware on flange behind the O2 *since only one bolt is on there now* after I get my grand prix started.

Re: Running Lean, nearly stock, wtf.
 

if i read this right you are still using the stock cx ecu? if so thats your problem. chip it and tune it

Re: Running Lean, nearly stock, wtf.
 

By "up top" I ASSume you mean WOT. In that case, no, a Honda ECU cannot compensate for a basic intake without leaning out.

Honda runs ther NA cars in the low to flat 12's from the factory, and since an intake doesn't do ---- for power you swing at most 0.03 AFR leaner. That's why you don't notice anything. :P

Re: Running Lean, nearly stock, wtf.
 

I'll be getting my AFC on monday so I can richen things up a bit and install my fuel pump whenever the ---- I get my FPR.

Definatly not, I'm using a OBD1 PR4 ECU. (1993 Integra LS ECU)

Re: Running Lean, nearly stock, wtf.
 

FPR arrives Friday, already have the pump.

Re: Running Lean, nearly stock, wtf.
 

i still think there is something else wrong if you are using the ecu that is for the engine. all you will be doing is covering a problem and not fixing anything.

i cant imagine there would be a difference, but i would do some research on the fuel pump and see if a cx pump is different than the reast of them

Re: Running Lean, nearly stock, wtf.
 

CURRENT part numbers come up the same as DX/LX/ and integra pumps.

HOWEVER, the part numbers come up the same for D16Z6 and D16Y8 headgasket, but they were different parts, with different specs before the 'merger'

I suspect this is the case again, with the car being a 92 and pre-wired for everything, and used D15B2 *IIRC, the old 4 valver* pistons, They may still have been using the old school pumps as a carry over like the pistons. A member of another forum I'm on basically said flat out "The stock pump out of a 92 will not support that motor" and the fact that it runs out of steam and go lean RIGHT where the CX motor basically red lines makes me think this is true. Regardless I needed the pump and FPR for when I boost, so I don't mind if this doesn't fix the problem, I'd be annoyed granted, but its still money well spent IMO.

ALSO, as mentioned, I guess the stock ECU cannot compensate for a basic intake, so this may also be an issue.

Re: Running Lean, nearly stock, wtf.
 

the fuel pump and fpr are fine, i just wouldnt use an afc to get it richer when tuning isnt the problem. i would look to a mechanical problem more than tuning

Re: Running Lean, nearly stock, wtf.
 

Yeah you clearly have a problem that you will want to address before adding things that will mask the problem. Be happy that you found this issue before you started adding parts.

Re: Running Lean, nearly stock, wtf.
 

I'm ditching the AFC in favor of a chipped ECU after all. I suspect mechanical problem also, but I don't have a stock air box to test with to rule out that variable :(. I also suspect that with 115K miles on the stock fuel pump that was fed City gas all its life that its probably on its last leg anyways.

Re: Running Lean, nearly stock, wtf.
 

Stock airbox, CAI, filter on a stick, or nothing at all just naked TB, will do exactly NOTHING to change your tune.

Reread what Cray said. Fix your mechanical problem before you start throwing parts at the car.

Re: Running Lean, nearly stock, wtf.
 

I just went back and saw ghetto turbo correct himself on the airbox thing, My bad.

I DO have new plugs and wires to throw on the car along with the FPR, fuel pressure gauge, and Walbro

Again, I have no problem 'throwing parts at the car' because these are parts it needs for my goals anyways, and MAY be part of the problem.

Sat morning I will be installing everything, I'll see how it comes out.

Fixing my exhaust leak droped the WOT from 16.8 to 16.0. (if I didn't already mention)

Re: Running Lean, nearly stock, wtf.
 

If the FPR is anything other than a large exit B series unit then it is not only a waste of money but a liability.

Fixing your exhaust leak changed the way your wideband reads, not the way your car runs.