turtleb16a

sup everyone,

i drop my b16 in about a month and a half (give or take) ago and the car started to hesitate, then be normal once i give it gas. its a minor hesitation when in going straight, but going on a hill, my car feels like its going to die out. thought it was the distributor, swapped that and still the same problem. it only got smoother since i had one bad wire in the dis. Changed the distributor, timing, fuel filter, bought the car with a gutted cat (hopefully soon to be carsound), put fuel injector cleaner once i got the car and drove it hard a few times, plugs are new (checked them, they are fine). not sure what else i can check out, started happening about a week after i got the car. can anyone shed some light?


[Modified by turtleb16a, 1:17 PM 7/12/2002]


[Modified by turtleb16a, 1:21 PM 7/12/2002]

EF_LSVtec

what kind of mods did you do to your b16...did you put a new timing belt, waterpump etc...before the swap? It could be that the timing belt jumped a gear and timing is off...

rice_classic

Timing belt.... that could be a bitch to diagnose.

My thought, O2 sensors. Assuming the car is utilizing both of them (which it should! ) then I would say they are in eachother location.. switch them locations with eachother and it might get better. I've heard of a lot of b16's having the problem when the o2 sensors are not in their appropriate location.

ULTRA911

my crx did that for the first 2months of this year. now it's july, and it runs really good! i guess you need to let it settle in. but, over the first 2months, i replaced rotor & cap, plugs & wires, ran fuel injector cleaner, and got new intake setup. during the whole time, i was always worried about the fuel pressure, like i'm not getting enough fuel into the injectors. also, check o2 sensors, it related to poor performance! my manual says it too and here, check out this site and read the bottom of the page:

http://users.ev1.net/~shinglin/cars/.../swapinfo.html

you could download the .pdf version of a vtec supplement (short helm's manual) designed for the crx b16a1 motors. it's like 7.2mb

http://www.carenthusiast.com/crxuk/VTEC_Supplement.pdf

02WRX

I'm running into the same problem - here's the details:

Hesitation happens primarily in low rpms (under 4.5k is where it's actually noticable).

Hesitation only occurs at partial throttle. If I put my foot to the floor, it goes away.

Hesitation occurs in any gear.

When driving at around 3.5k - 4k in 5th, the feeling isn't so much hesitation as it's a cycle of hesitation & small surge.

New/replaced items during/since the swap on June 28:

Timing belt - h2o pump - plugs - wires - cap - rotor - fuel filter - TPS - rebuilt distributor - alternator - throttle cable - clutch.

Aftermarket parts & setup:

AEM Cold air intake - custom exhaust - DC 4-1 Ceramic headers, with an extra o2 bung installed next to the stock location. I'm running both o2 sensors.

Other service items done:

Valves adjusted - all fluids replaced (duh - motor swap) - might be more, but I can't remember anything that might be relevant.

I've checked the plugs & engine fluids several times since this started happening & they're all fine. The other day after I replaced the TPS & fuel filter, I thought I had it fixed, but after a while it came back. I had reset the ECU during this process, so I wonder what the possibilities are that the ECU could be trying to adjust itself to the cam timing. If the cam timing is off a tooth, maybe the ECU is trying to adjust for it, but is only able to get it right at higher rpm's? I dunno...just trying to throw out some ideas...

Here's a couple of ideas, hopefully someone can tell me if they're even a possibility:

Timing belt off by a tooth?
Ignition timing off? (This doesn't seem right, but can't hurt to ask)
Coil or ignitor problem?
o2 sensor problem? (Maybe try wiring both wires to read one sensor?)
Sticky throttlebody?

That's about all I can think of right now. If anyone can say yes or no for sure to any of these ideas or has any other ones, that'd be great!

Eric



[Modified by 90CivicEX, 7:46 PM 7/14/2002]

FBPninetynineEM1

i have the same problem, but i have a ZC someone on the board told me it could be that my valves need to be adjusted. maybe you guys might wanna try that

Sgt_Ox

How about swapping the wires around first between both o2 sensors vice wring them together. That more than likely should solve your problem. I wouldn't recommend splicing both sensors together, you'll just just run into the same or similar problems. Here's what happens when the o2 connections are backwards (ie.....primary terminal connectected to the secondary o2 sensor) you have I pair of cylinders 1 & 4 (this is the primary pair) will run 20% richer and the secondary pair cylinders 2 & 3 will run 20% leaner then alternate causing the fluctuation in acceleration. If you understand this concept about how the dual o2 sensor works then you'll understand what will happen if you just slice both senors together to the primary terminal leaving no signal to the secondary terminal.

Bryan

02WRX

Yes, but my o2 sensors are right next to each other in the collector of the header, so I can't see how reversing them will make any difference. In addition, the connectors for the sensors are different, so all I'd be doing is changing the position of the sensors by swapping them out...

Eric

brian.edge

check your MAP sensor........
i had the same problem you guys are having and that ended up being my problem

02WRX

One more bit of info to add:

There is almost no hesitation when the car is cold - it's only noticable once the car is up to normal operating temp...

Eric

Bleed Black

Did you change your plug wires? I had the same problem and changed fuel filter,plugs, and put injector cleaner in and still same problem. I decided to change my plug wires(which werent old) and car ran perfectly . I would at least change those if you havent just to make sure.

USDM 4G VTEC

i am getting the same thing on my mini me....i got it 3 days ago...
i drove like 80 miles yesterday and i started noticing that theres a little hesitation... like misfirin every now and then while going cruising,,,,partial trotle..... i floor it and its ok.....its not hard, but enough to feel it... i had denso iridiums spark plugs..... i changed them for some bosh platinums....it felt that it went away... today i went out and while steping on the car a little... it started doing it again. but more noticeable.... i can feel it....i am getting spark plugs tomorrow to see if its that or not.... bc my #1 spark plug tip its black on one side of the gap and the other side its clean.... the other spark plugs are nice and clean.... i am thinking, that after i changed the plugs, i am checking the rotor.... if not then i gotta get the cables..... this happens when the car its hot, not cold.... its inda pissing me off, bc since the engine was rebuild its scaring me that i fucked something, by steping on it.... any ideas.... i kinda see some people had it and if u did , how u fixed it??

out2wincrx

yeah if anyone figure out this hesitation thing let know i'm having the same problem by the way does anyone know how check and see if tps is adjust right mine has been changed before

turtleb16a

im ordering an O2 sensor to see if that could be it, thats the only thing i havent swapped out. still kind of new with dianosing these motors. anyway i can check the MAP sensor myself? (guess i should do a search, ha ha ha.) anyways, ill try the O2 and let you guys know. thanks for all the info!!

SuperCivic

that's the one that i'm having too. here's another point, at least for me..it was happening in my d16a6 motor before i swapped it out for the b16. i did reuse the o2 sensor, and i picked up another one at a junkyard. hmmm..

btw..when using a b16 stock exhaust manifold, which o2 is the primary?? the one closest to driver side or passenger side??


[Modified by SuperCivic, 1:52 PM 7/15/2002]

SpooN Man

I have the same issue

Nothing but a clutch, plugs cap and rotor was changed before the swap

Here is my setup

b16a 89 block and head.
stock exhaust man. both 02's
ecu: Factory pr3 also 89
No cat


I think I am going to try to reverse my o2's and let you know what happens.

I only have an issue when tring to hold a constant speed on level ground say 10% or 20% open throttle. as soon as I give her say 30 % it goes away.

02WRX

I think I got mine. Went by & talked to the master tech @ the dealership. I explained what was going on, he said that the only thing that would affect performance that changes between cold & hot temps is the o2 sensor. So I got new o2 sensors. The dealership wanted $115 (wholesale), which was a bit steep, so I went to my local parts shop. I asked for NGK, but they didn't stock them, so I took two Bosch 1 wire o2 sensors. I went to put them in, but because of my own stupidity, the 2nd o2 wasn't going to fit (clearance to the shift stabilizer - don't ask...). I ended up splicing both o2 sensor wires into a single o2 sensor. Fired up the car & went to the store. Still had some hesitation, although not as much. On the way to the store, I realized that resetting the ECU would probably be a good idea & so far everything seems good after resetting it! I'll try for a follow up post in a day or two, but I'm pretty happy at the moment!

Eric

Sgt_Ox

"90civicEX"

Just to clairfy things a bit and general information. If you actually look into the stock manifold of the 1st gen b16 you'll notice that cylinder 1 & 4 runners combine to one of the 2 down pipes, and cylinders 2 & 3 also combine the other down pipe. So therefore the O2 sensors can actually be reversed and cause a loss in performance. Yes the secondary O2 sensor has a different plug but 50% of the time that connector has been cut off when the importer recieves the engine. That's where most of the guys have problems with the O2 sensor polarity.

Bryan

Sgt_Ox

"turtleb16"

You should be able to do the a vacuum pump test on your Map sensor to check inconjuction with a multimeter. However if the O2 sensors are reversed this hesistation should only happen when it is warm. And more than likely occur mid-RPM range.

Bryan

customx_

how do u remove the o2 sensors from the mani?

4gvtec

use a closed end wrench,forgot what size.spray with blaster first or wd-40.or a deep socket.dont use a o2 sensor socket they suck ***.

USDM 4G VTEC

well i got a new O2 sensor on thursday.... and saturday its when it started doign the hesistation.... it cant be the O2 sdince its only 5 days old...... i change spark plugs today. still there.... i dont wanna spend 35 on enw cables... they are only 2 months old..... i chequed the cap and rotor, they are fine and have been only used for 1 week.... i got a code 9 .. wich had before the hesitation.. i wanna know if it might do something about it.... i am going back to the shop tomorrow and ask them.... bc i apyed a shitload of money to fdix it and 3 days after it starts doing this..... ill let u guys know what they say....

02WRX

Did you reset the ECU after replacing the o2 sensor?

Eric

USDM 4G VTEC

i have reset my ecu about 6 times already since thurday....

i payed too much to the shop. i am taking her back and tell them to kinda fix it bc that its too soon.... they gave it to me with that code!


[Modified by JDM EF9, 10:36 PM 7/15/2002]

pelotudo

Ack, I used to get that all the time. I replaced my o2's, Plugs, Wires, fuel filter, and air filter...and still nothing. Added fuel system treatment and it went away for a while but came back.

It isn't doing it very much right now, but I can still notice it a little bit when going uphill or when keeping a steady pace.

Anyone figured this one out yet?

BTW, I had a full tuneup about 2 months ago (Valves adjusted included)

jB