hondabinge

hi y'all. have a question i was hoping someone might help me out with.
bought a 94 civic vx with 164k last fall and parked it for the winter. trying to get it running right now. when i bought it there was a check engine light for 02 sensor. car had a major dead spot when driving it. replaced the 02 sensor/air fuel meter (considered the same thing on the vx model i guess) with an aftermarket one. dead spot went away when you first started driving car but is still there once the car warms up. no check engine light anymore.
trying to figure out this problem. i tried fuel injection cleaner, coil, dist cap, spark plugs, plug wires, map sensor, fuel filter, and it is still doing the same thing. when i say 'dead spot' i mean that if you try to maintain speed the car kind of chugs and has no power when you are pushing the gas peddle. just weird that it does this when only when the car is at operating temperature. now i've had a few of these vx models in years past and everyone of them had the same 02 sensor problem and dead spot. i would normally just change that and they would be fine.
so any idea's? cat. converter maybe? tps sensor? ecu? fuel injectores themselves?
thank you

95hatchcx

bad fuel pump or fuel filter?

civic_driver

I would check the TP (throttle position) sensor

itsmejto

X2 on the TPS, that was my problem. Same issues.

hondabinge

thanks. i will give the tps a try first and if that doesn't work i will try to switch out fuel injectors.

bonies

wa kind of ecu u run right now and wats ur engine...

hondabinge

stock engine and ecu
P07 ecu
D15Z1 engine

Former User

Inspect your EGR system.

articsilber323

anything to inspect,

i have one doing the same thing has brand new o2 sensor

if i unplug the egr the CEL DOES NOT come on and the car runs great

what should i check out

sniffbooger

Hi I didn't want to start a new thread since I guess this is a common problem??

I too have a 1994 VX and its doing the same thing... hesitating and stumbling badly at cruise speed. It only does this when its warmed up, and ONLY IN 3RD-4TH-5TH GEAR!. Runs perfectly at all temperatures and all RPMs in 1st-2nd gear. Engine does not hesitate in default mode. Only hesitates in closed loop operation 3rd-4th-5th gear. Go figure.

Last week I replaced the O2 with a new Walker because it was throwing code 48. Now the CEL is off, but it runs like poo poo when warmed up.


How could it be the TPS or EGR when it runs perfect in 1st and 2nd gear at all temps/rpms?

Any help would be appreciated!

Relic1

keep in mind the VX enters what's called a "Lean Burn Mode" this runs the engine very lean (high mpg) the problem is when you exit this mode it stumbles slightly, like it hesitates then accelerates. At times it can feel like the car doesn't respond till you give it way more throttle than you should have to.
But this will only be after cruising for a little bit then trying to accelerate.
This is normal for every VX and HX I've ever driven. the HX does it a lot less since it runs the lean burn mode less often and has much tighter tolerances for entering and exiting this mode.

Also, when you repalce the O2, make sure you reset the ECU after doing so. The P07 ECU uses the O2 very hevily, so if you don't clear the intermal memory of the bad O2 it will take a while for it to figure out that the O2 is trust worthy again.

sniffbooger

The hesitation is much worse than a slight stumble. The engine misfires and stumbles badly when you step on the gas (only when in 3rd-4th-5th gear after cruising) and it loses 3-5 mph before it starts to pick up again. And then if I let off the throttle, it goes right back to missing again and losing power. It will not maintain 65 mph on the freeway unless you constantly jockey the throttle. It is not a short hesitation as though it were changing from lean burn mode to standard.

It feels like the way my wife used to drive because she was too short to reach the gas pedal without stretching her foot way out and couldn't maintain the pressure without letting off for a couple seconds of rest. This resulted in a sickening back and forth motion that was really annoying.

Again, why does it run so perfect in 1st and 2nd gear, even when at cruising speed and then quickly accelerating? No hesitation at all... but soon as you put it in 3rd, it starts to run crappy.

The CPU was reset when the 02 was installed.

92cvchtch

im having the same problem as well, when the car goes into leanburn it wont cruze. not over maybe 50mph. and its rough. attempting to drive on the highway is a pain. at 70mph the car will go into leanburn and slow down no matter how much throttle i give untill int disengages lean burn and quickly starts accelerating and then will engage lean again and slow. i can hold the throttle at the same position and it will do this on its own. laging down to 60-65mph and then bouncing up to 75 or so and then lagging down again. it wont cruze in leanburn. and in all gears but 1st and 2nd will have stalling and extreme hesitation around 2000rpm.

some ideas please.

LudeToAHatch

Did you ever find out what the problem was? I have the same issue on my 93 vx!... grrr

slogfilet

iTrader: (1)

Checking/cleaning the EGR valve is easy to do... cleaning the EGR ports is a bit more involved, but definitely worth looking into.

Check your PCV valve... the VX originally came with just a 90* elbow (no innards), but the part is no longer available. If you gut a new PCV valve, you'll basically have the OEM part.

A Walker O2 sensor is likely not the right one, even if it says it is. You'll need an NTK 24300, and expect to pay at least $200 for the right sensor. The O2 sensor is integral to lean burn operation, so there's no skimping on it if you want the mpgs and smooth operation. There is also a Bosch sensor.

Test your throttle position sensor and clean your throttle body. While you're at it, clean your IACV.

tegonfire

Hey I do mechanic make 10 years and I have 2 Diploma(car mecanic/heavy duty truck mecanic) and I have the same fuking problem I cant get rid off...

My car is a Integra b18b and sometime go fine then sudenly,I hit gaz pedal and between 2k-3k rpm the car stop accellarating and I have to wait 2-3 sec before it finely accel or I have to push the pedal so deep to catch the flat spot back...

When I drive people behind me look me like I am a retard maniac...

Here what I done so far ...even after I have tested every sensors and they were good I change them for brand new...

NO cel code
-new ecu
-new map
-new tps
-ecu reset
-no vacum leak
-new main relay
-test pipe
-fuel pressure test is normal
-new IACV
-new distribbtor
-new spark plug and wires

Now am starting to think the only think left could be fuel injector leaking real bad or short in the big ecu harness????

Any body got any idea what the dead flat spot that come and go could be???
Anybody ever get rid of this problem???
its the only problem in 10 year I cant get rid off!!!

WTF???

tegonfire

On ebay you can order new Tps and map including shipping for like 8$ each but take like a month to get them from china
And you can sell them back 40$ each on Kijiji or other web site to sell your old scrap...


FIXED ITS THE PRIMARY 02 TROWING NO CEL CODE!!!

DEad flat spot wont suddently accel between 2-3k rpm

MOTHER ******* PRIMARY 02 not trowing any code

REPLACE IT EVRY ONE