sup fellas i resently installed an autometer air/fuel ratio gauge into my car...my problem, car hestitates when cruising at about 2500 to 3500 rpms. it feels like your giving gas then letting off giving gas letting off... when you get out of that range or accel fast you dont feel it, anyone know whats up?? could it be a weak connection or bad ground??? also my gauge is lit up on the very last bar on the rich side and doesnt sway from lean to rich in idle mode like its suppose to...any info would be much appreciated

 

Almost gauranteed to be an O2 sensor problem. My car was doing the same thing. I replaced it and the problem went away.

 

heh my o2 is brand new bro it never had this prob b4 the install so ill just wait on getting a new o2 sensor...thatll be my last resort, thanks for the info though

 

well the gadge question is simple it is oviouslly ground and has a power sorce so it has to be a bad connection.

 

Well I can say that I had the same problem that you are having as far as the hesitation is concerned. I had the air fuel meter before the hesitation started. I always showed the idle bounce on the meter. Also my hesitation was always between a given rpm range and once outside that range it was fine. Need a little more information. is the hesitation when the car is warm or cold or both? If the hestitation is when the car is cold, I would then pretty much eliminate the O2 sensor in my opinion. The O2 isn't feeding back to the computer until it heats up. As the car warms up and the problem starts, then O2 would be a good start. As for the A/F meter, I would first check the connections on the A/F meter to see if the connections are correct. ( I'm not doubting your ability) just asking to double check. It could be the signal wire is attached to +12V which would give you a constant full rich. Make sure of the signal connection. Also when I start my car, my A/F meter usually starts out at towards lean and as the sensor heats, the meter gets richer until full rich. Then when the sensor got to a point where it was warm, i got the idle bounce.

My next question is are there a lot of mods done to the car? Because my problem with the hesitation was that I had quite a few mods and was running the stock computer program. I know that when I got my computer upgraded, the hesitation went away. My personal theory is that the computer could only correct the fuel up to a certain point and i was beyond that point between those RPMs. I figure that most driving is done between those rpm's on an average drive. And from what I've been told, Honda's run fairly lean for added fuel economy. So maybe a fuel controller or computer reprogram will solve the problem like it did for me.

Back the the a/f meter. I did however lose my idle bounce on the a/f meter with the computer reprogram due to the richening of the fuel program. Now my meter is pegged at full rich all the time. I guess I need an egt meter and maybe a V-AFC.

I'm no mechanic or even claim to be... I just know what worked for me and hopefully my information can help out. If i'm way off... sorry. I can only go by personal experience.

 

Also, with the air/fuel guage, did you install an fuel pressure regulator with it and made some adjustments? Did this problem occur after installing the air/fuel gauge?

 

my car only hesitate when its at normal running temp, when its cold it feels normal i dont feel the hesitation so guess it is my connection to the o2 sensor wire causing the prob

I connected it to fuse 15a under the steering wheel where did you connect yours to?

nope nuthing done to the car exept for suspension

you pretty much on point bro what you said is exactly whats happening to my car thanks for the help

 

no i dont have a fpr and yes this problem did start after i installed the a/f gauge



[Modified by Squeeze, 2:09 AM 1/5/2002]

 

O2 Sensor?

No way! I would chk all connection first. The possibility that the O2 sensor just went bad after the install = 0.

 

im pretty sure the o2 sensor isnt bad, but im almost 99% sure the o2 wire i tapped into has the prob

 

Yeah! Chk all connections!
Good luck!

 

Please dont listen to any kind of advice this jerkoff would give. If you dont believe me do a search on anything thiat he has responded to and you will understand what Im saying.
As for your problem. It may be your connection with the gauge. BUT that gauge wont give any kind of negative feedback to your engine. Another words, even if it was hooked up wrong it wouldnt have any kind of effect on how your car runs.
I know I was short in my response. But I had the same probelem-- a little more intense, but it turned out to be the O2 sensor. I replaced mine and that was the problem. What you might want to do is check to see if your getting a check engine code. From what I've seen, sometimes it doesnt always light the idiot light on the dash when theres a problem. Check for that for sure.....

 

im pretty sure its where i t-tapped into the o2 sensor wire at the ecu i guess i have to resolder there im sure its not my o2 sensor coz b4 i messed with this connect my car ran fine...thanks for the info though

 

93LSivic gave me wrong information on 12/14/2001 on a trans question I had. Most of the time he doesn't know what he is talking about.
I hammered him for it and then he went back and DELETED everything he said. Now he is pissed!
Sorry, 93LSivic, but you asked for it!

 

Well, the only thing that I would do is disconnect the guage. If you return everything back to stock, then I would most likely think that it would be that O2 sensor. If not, then obviously their is a bad connection somewhere. Come on guys, no hammering needed-only TECH q's and a's.

 

ive got one more question for you i cutt the o2 sensor wire in half and extended it with another piec of wire so i could tap into it easier do you think that had an affect to the sensor recieving the proper 12v? any info would be much appreciated

 

Well about the question on 12V. I tapped my gauge into my fuse box. I just tapped into an empty location on the battery side of the fuse. You said in an earlier post, that is where you tapped yours... correct? If so, then that should be fine. Another thing would be to check the ground wire. Make sure the gound has a good connection. As for the signal wire... I tapped mine right off the O2 sensor in the engine bay. I tried to stay away from tapping anything near the ECU. There is too many wires by the ECU to be messing with in my own personal opinion. Also with tapping off the O2 sensor directly, there is only 3 wires to choose from. To determine which one is which, unplug the O2 sensor (if an option, GSR has a wire harness connection for O2). Turn the ignition to on but don't start the car. Take a mulimeter and connect the ground wireof the meter to chassis. Now measure each wire. The 12V signal is obviously battery, the 0V signal is ground, and the other voltage is the signal wire. The signal wire will be a very small voltage... between .1V and .9V. This keeps from choosing the wrong wires by accident. . Also in case the O2 sensor goes bad, all you have to do is unclip the sensor and replace it. You will have to re-tap the sigbal wire but saves lots of trouble guessing on ecu wiring.

I don't really know if the wire that runs off the O2 sensor is the same wire that the ECU reads from. That would be something that you would have to check the ECU scematic for. But I also agree what others have said... remove the gauge and double check to see if gauge is causing the problem.

If you remove the gauge, reset the computer before driving just in case the gauge did feedback to the computer. This way the computer can start out fresh with new numbers.

Other information which could come in handy (you may already know). The A/F meter is just a fancy voltmeter. It reads usually from .1V to .9V. The lower voltage being lean and the higher being rich.


I'll keep checking the posts to see what you come up with.

 

hey whats up bro how would i go about checking to see if the gauge is causing the problems? it lights up but doesnt read anything, it just stays on last bar on rich...it should be swaying from lean to rich during idle right? it doesnt do that either...my connects are as good as its gonna get coz i resoldered everything...btw thanks for info i appreciate that. one more thing do you have pics of how you ran the signal wire to the o2 wire in the engine bay?

 

Well now... I am sitting here with the ECU wiring in front of me and I just realized that you are OBD2 correct? Which means you have 2 O2 sensors. I'm assuming on the obd2 because of the picture of car by your name. I don't think it matters which O2 sensor is tapped... but I am looking into it. I believe the 2 numbers are compared by the ECU to make the final decision on fuel requirements but not sure yet. I will know more by the time you reply back.

First, I will need to know the which car you have. By the picture... I'm assuming it's a Civic...? I need to know year and model (CX,HX,EX,LX) it will make a difference on wire color. Next I will need to know which wire is tapped (wire color) for the signal to the gauge. This way I can check to see which one it is and if it is the correct one.

After looking at the wiring diagram... It seems that it would be very easy to grab the wrong wire.

As for pics of my engine bay... I can't get any right now. I will try to get some so I can forward them to you. But I can't guarantee when. Sorry.

Did you try removing the gauge and reseting the computer to see if the problem went away? If not... I would still recommend doing that. It would take about an hour to do.

In case of not sure of how to reset the computer...

In this case... remove the A/F gauge from the car. (just disconnect the signal wire)

When the car is cold, remove battery (pos) cable. Let the car sit with battery disconnected for about 30 min. Reconnect battery. Start car ( be sure not to rev car or anything once started). Let the car warm up to normal operating temp. Now drive the car normal for about 15 minutes to get the computer some numbers.

Now go about driving the car like you normally would to see if the hesitation problem is still there.

Let me know the info on which model and year of car you have, and the color of the wire you have tapped for the gauge. Try removing the gauge and resetting the computer also to see if it fixes the problem. If this was a major problem, you would probably get an error code from the computer. But don't quote me on that.
Hope to hear from you soon.

 

hey whats up man i have a 98 hx i tapped into the white wire (it was the thickess wire) of the middle harness (blue) the other 2 harnesses are grey also at first i did get a cel then i had the ecu reset and the cel went away but it still had the hestation...thanks for all the help bro im thinking of just getting a used harness somewhere and then tap into the o2 from the engine bay

 

Ok i found what could be your problem... I have the wiring diagram and for the HX it shows 3 wires on the primary O2 sensor. If you get under the car and physically look at the primary O2 sensor there should be a White, Red, and Black wire.

If this is correct... they are as follows

White............. VS+ (this is probably the battery or ECU power source)
Red................ VS-, IP- (this is probably sensor power/signal ground)
Black............. IP+ (this is probably the signal wire that you need)

If you are looking at these wires at the ECU, they should be right next to each other in the harness because on the wiring diagram, they are connections 21,22,23.

if these follow suit for your car... then you would want to tap into the black wire.

If you don't know which is primary and secondary O2 sensors, I believe the wire colors are different. So the sensor with the wire colors described above is the primary.

Also... as I look further into the wiring diagram... there is another white wire.

The other white wire is connected to what seems to be the Crank Angle Sensor, or Cam position sensor. I don't know what the abbreviations stand for but it is as follows.... CKP so i'm assuming its the crank angle.

The wires that are around that portion of the harness are the same colors as around the O2 sensor portion of the wiring harness. So this could essentially be the problem. You could be tapped into the wrong area.


You best bet is to tap the O2 sensor in the engine bay close to the sensor where you can actually see the wires from the sensor. Then run the signal wire through the fire wall and connect to the gauge.

As for the hesitation... if it kicked out a code before... maybe it will kick out another one. then you could get the code read and see what the problem is.

As for the gauge... if you retap the signal wire near the sensor (black wire) the gauge should work properly. I hope! I wish I could help more with the hesitation problem but I don't really know what else to try right now.

the only thing now would be to check all spark plug connections, or fuel filter ( simple things which could cause the same problem)

The other thougth would have been that the impedence of the gauge tied into the white wire could be dragging down the O2 sensor circuit. (electronic stuff. I'm an electronics engineer). This would cause a normal 12V signal to drop below 12V and the O2 sensor may have given wrong readings to the ECU due to lack of power to the sensor. (Just a thought)

I'll keep checking to see how it goes. Good luck!

 

thanks for all the help bro where did you get the wiring diagram for the hx???

 

Go to Pep Boys or some simple auto store and buy the Automotive repair manual.

Here is the details on it.

Haynes auto repair manual (green cover with picture of integra on front)

Honda Civic 1996-1998
Acura Integra 1994-1998

Both cars are shown and all models are covered.

I think it cost me about $15 but not sure.

Hope everything works out!