2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.
Sponsored by:

Car little rough, o2 sensor?

Thread Tools
 
Search this Thread
 
Old 07-09-09, 09:56 AM
  #1  
Full Member

Thread Starter
 
luyo's Avatar
 
Join Date: Oct 2006
Location: Peru
Posts: 83
Likes: 0
Received 0 Likes on 0 Posts
Exclamation Car little rough, o2 sensor?

I had couple of problems with my car and It was electric things, now I change the o2 sensor (bosch universal) .

Sometimes I feel my car rough (and I say rough cause when I just change the o2sensor and reset the ECU I felt it very smoth and free) I dont know if it has to do with the o2 sensor cause sometimes the check light goes on but then goes off.

What should I look??

Thanks!
Old 07-09-09, 10:02 AM
  #2  
Engine, Not Motor

iTrader: (1)
 
Aaron Cake's Avatar
 
Join Date: Feb 2001
Location: London, Ontario, Canada
Posts: 29,789
Likes: 0
Received 108 Likes on 91 Posts
When does the car feel rough? The O2 sensor is only used at light loads during cruising.
Old 07-09-09, 10:09 AM
  #3  
Full Member

Thread Starter
 
luyo's Avatar
 
Join Date: Oct 2006
Location: Peru
Posts: 83
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by Aaron Cake
When does the car feel rough? The O2 sensor is only used at light loads during cruising.
Almost all the time, I will try to reset the ECU right now and see in about 4 hours... What do you think??
I think , not sure, when the light is on and i hit the gas and race the light goes off...

Like i said when I just put the new o2 sensor and reset the car was fine till then becomes a little rough , was easy for me to feel the diference between before and now
Old 07-09-09, 10:54 AM
  #4  
MECP Certified Installer

 
jjwalker's Avatar
 
Join Date: Feb 2009
Location: Mesquite, TX-DFW
Posts: 3,176
Likes: 0
Received 2 Likes on 2 Posts
Is it happening only at a certain throttle position or a small range of trottle position? You could have a bad spot in your narrow range TPS (assuming this is an s5).

You should have a code stored if the light came on. Reproduce the problem then check the codes and tell us what it is.
Old 07-09-09, 11:08 AM
  #5  
The waiting game......

iTrader: (18)
 
2slow4stock's Avatar
 
Join Date: Feb 2005
Location: North Aurora
Posts: 2,275
Likes: 0
Received 3 Likes on 3 Posts
Is the car s4 or s5? Regardless, check codes.
Old 07-09-09, 11:29 AM
  #6  
Full Member

Thread Starter
 
luyo's Avatar
 
Join Date: Oct 2006
Location: Peru
Posts: 83
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by 2slow4stock
Is the car s4 or s5? Regardless, check codes.
Oh sorry its s5 91 gtus rx7 , the codes are:

17 , 30, 33, 38 .... (Somebody told me 30, 33 and 38 are not a problem) you tell me...

I already put and o2 sensor (bosch - universal) and the signal is getting good to the ECU by the way.... The codes dont tell me nothing about Tps (I read that s5 tps set up itself )

some help plz
Old 07-09-09, 11:53 AM
  #7  
Are you experienced?

iTrader: (18)
 
jjcobm's Avatar
 
Join Date: Oct 2008
Location: Illinois
Posts: 2,099
Likes: 0
Received 1 Like on 1 Post
Make sure the cable you spliced into the universal O2 sensor doesn't have the "grounding" shielding. It should just be wire in the middle and not wire in the middle, then layer or rubber, then another outer layer. (I read here some series have this, but my s5 doesn't, but its good to check).

On the side, you do have emissions codes. Although none of these codes themselves should make your car run rough, unless you haven't removed emissions it would be something to get checked. It is possible one of the lines on the solenoid rack (on the drivers side, by oil filler) is unhooked and you might have a vacuum leak, which will ALSO throw off your O2 sensor readings. Not to mention some of these solenoids are RESPONSIBLE for your 6 port injection. Your car could probably be running rough in the first place due to this. Check over the lines....

As far as the TPS, if you have a multimeter now is a good time to check it out. Just backprobe the red/green wire, set it to 20volts, and set the screw until you get 1v. All this on a fully warmed up car. It doesn't hurt to check.

If you have tried everything and are still getting that one code, alot of times that universal bosch sensor will give you that error code. I am really sure the reason for this is because the design of the univeral vs. the OEM one. They have completely different design and purposes, if you look at the OEM it is build way better than the universal one, and possibly the calibration for the universal is not good enough for the stock ECU. Your best bet is just to buy the OEM one.

Here is a good deal where I got mine from:

http://www.amazon.com/gp/product/B000CEZR8O

Good luck.
Old 07-10-09, 02:10 PM
  #8  
Full Member

Thread Starter
 
luyo's Avatar
 
Join Date: Oct 2006
Location: Peru
Posts: 83
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by jjcobm
Make sure the cable you spliced into the universal O2 sensor doesn't have the "grounding" shielding. It should just be wire in the middle and not wire in the middle, then layer or rubber, then another outer layer. (I read here some series have this, but my s5 doesn't, but its good to check).

On the side, you do have emissions codes. Although none of these codes themselves should make your car run rough, unless you haven't removed emissions it would be something to get checked. It is possible one of the lines on the solenoid rack (on the drivers side, by oil filler) is unhooked and you might have a vacuum leak, which will ALSO throw off your O2 sensor readings. Not to mention some of these solenoids are RESPONSIBLE for your 6 port injection. Your car could probably be running rough in the first place due to this. Check over the lines....

As far as the TPS, if you have a multimeter now is a good time to check it out. Just backprobe the red/green wire, set it to 20volts, and set the screw until you get 1v. All this on a fully warmed up car. It doesn't hurt to check.

If you have tried everything and are still getting that one code, alot of times that universal bosch sensor will give you that error code. I am really sure the reason for this is because the design of the univeral vs. the OEM one. They have completely different design and purposes, if you look at the OEM it is build way better than the universal one, and possibly the calibration for the universal is not good enough for the stock ECU. Your best bet is just to buy the OEM one.

Here is a good deal where I got mine from:

http://www.amazon.com/gp/product/B000CEZR8O

Good luck.


When I changed the o2 sensor I saw one wire through th ECU no more connections.

what you mean by removing the emission codes? (I already reset the ECU if thats what you mean)

ABout the solenoids pack, i check it and everythings ok, Is it neccesary to clamp the tube lines?

ABout TPS, my iddling is normaly in amost 1500 rpm (obvious is too much) but when I turn on the lights the rpm goes to 1100 rpm, Im afraid if I put the rpm to 800 when I turn on the lights and maybe use brake pedal the car goes off. I will do try to set it right anyway.

And something important I didnt tell is that my car dont have air control valve

http://cgi.ebay.com/ebaymotors/Mazda...Q5fAccessories

and I think this has to do with 6 ports (error codes 30, 33, 38 that I told you), should I put ths air control valve again?? (My car have headers and no catalized)

You tell me what do I have to do?

Thanks, keep helping plz
Old 07-11-09, 10:49 PM
  #9  
Are you experienced?

iTrader: (18)
 
jjcobm's Avatar
 
Join Date: Oct 2008
Location: Illinois
Posts: 2,099
Likes: 0
Received 1 Like on 1 Post
When I changed the o2 sensor I saw one wire through th ECU no more connections.
Good, just make sure it is connected properly. This is most likely not your problem at the moment, the O2 is just doing its job and since you most likely have a vacuum leak somewhere or improperly set TPS, it is giving you this error code.

what you mean by removing the emission codes? (I already reset the ECU if thats what you mean)
I meant if you removed emissions equipment such as the ACV, airpump, ect... which you stated you did in the recent post. Since you removed the ACV, did you also remove the air pump? What series car do you have, s4/s5?

ABout the solenoids pack, i check it and everythings ok, Is it neccesary to clamp the tube lines?
You don't need to clamp the vacuum hoses, they should fit snug.

ABout TPS, my iddling is normaly in amost 1500 rpm (obvious is too much) but when I turn on the lights the rpm goes to 1100 rpm, Im afraid if I put the rpm to 800 when I turn on the lights and maybe use brake pedal the car goes off. I will do try to set it right anyway.
When did your idle get this high? After removing the ACV? Idle this high is not normal, you could be experiencing a vacuum leak. Set the TPS to 1V. Set idle to 850. Your car shouldn't stall because of the lights going on and what not. The ECU compensates for these things through the BAC.

and I think this has to do with 6 ports (error codes 30, 33, 38 that I told you), should I put ths air control valve again?? (My car have headers and no catalized)
Those codes do have to do with the 5/6th ports like I stated before. Since you removed the ACV and if this is an S5 we are talking about, they are no longer funtioning, you are loosing alot of power unless you wired your ports open.

I am assuming you have an S5, so correct me if I am wrong. After you set the TPS, and set your idle and things still are acting up you will have a few choices. One is to replace the ACV and hook everything back up like stock, see if the code O2 sensor code dissapears. The other codes you shouldn't worry about, only the O2 one. Second choice, since you already removed the ACV did you make sure to block off the vacuum passages with nipples from where the vacuum lines went to the ACV?

Usually if this is an s5 and you removed the ACV, you should just removed the airpump, then the whole solenoid rack. Block off all the unused nipples on the intake manifolds, run the air bleeds for oil/fuel injectors to the top nipple on the side of the intake manifold (runs to fresh air not vacuum), ect....... ( i can tell you the whole procedure...)

By the way, if you really need an ACV, let me know or post in the classifieds here. I wouldn't go to ebay, its overpriced. I just pulled mine out of my S5, works good, its really clean and you can trust you are getting it from a good member here.

Keep me updated.....
Old 07-11-09, 10:56 PM
  #10  
Former FC enthusiast

iTrader: (2)
 
KhanArtisT's Avatar
 
Join Date: Dec 2004
Location: Northern VA
Posts: 2,841
Received 2 Likes on 2 Posts
Its not the O2. O2 will never cause a hesitation, rough idle, stumbling, anything of the sort. Disconnect it and see for yourself.
Old 07-11-09, 10:59 PM
  #11  
Are you experienced?

iTrader: (18)
 
jjcobm's Avatar
 
Join Date: Oct 2008
Location: Illinois
Posts: 2,099
Likes: 0
Received 1 Like on 1 Post
Originally Posted by KhanArtisT
Its not the O2. O2 will never cause a hesitation, rough idle, stumbling, anything of the sort. Disconnect it and see for yourself.
Thats true, I was stricly speaking about the O2 throwing the code due to a bad connection, but even that is not his problem, he most likely has a vacuum leak making the O2 read lean all the time....
Old 07-12-09, 09:22 PM
  #12  
Full Member

Thread Starter
 
luyo's Avatar
 
Join Date: Oct 2006
Location: Peru
Posts: 83
Likes: 0
Received 0 Likes on 0 Posts
I do have a s5 91

I will set the TPS and see how it works... anyway I think the powerless will keep until I do sometihng with the ACV right?? what you recommend, put it again the ACV or wired the ports?? since I dont have cats...

I do have the racks and I thing the air pump too installed, just no ACV and its block with a flat metal (not sure if it has gasket or something) I dont know is I have to block anything else? I dont know where are the other wholes it comes to ACV...
Old 07-13-09, 06:06 AM
  #13  
Rotary Freak
 
HAILERS2's Avatar
 
Join Date: Jul 2008
Location: FORT WORTH TEXAS
Posts: 1,660
Likes: 0
Received 1 Like on 1 Post
The ACV has to have a gasket on it to seperate the three sources of vacuum under that plate, from the sources of exhaust gas and ambient air. Pull it off and make sure there is a gasket there.
Old 07-13-09, 04:49 PM
  #14  
Full Member

Thread Starter
 
luyo's Avatar
 
Join Date: Oct 2006
Location: Peru
Posts: 83
Likes: 0
Received 0 Likes on 0 Posts
Ok I will check it but It could be better with the ACV again?? or its ok like this...?? how much power Im losing?
Old 07-13-09, 07:50 PM
  #15  
Are you experienced?

iTrader: (18)
 
jjcobm's Avatar
 
Join Date: Oct 2008
Location: Illinois
Posts: 2,099
Likes: 0
Received 1 Like on 1 Post
Unless you know what your doing, keep the ACV. Replace it as if you run without it you either have to have them fully open, or fully closed. The ECU will do all the work for you with a working ACV.....
Old 07-13-09, 08:30 PM
  #16  
Rotary Freak
 
HAILERS2's Avatar
 
Join Date: Jul 2008
Location: FORT WORTH TEXAS
Posts: 1,660
Likes: 0
Received 1 Like on 1 Post
Series five auxillary ports are operated by airpump pressure and a solenoid controlled by the ECU. The exact routing of the air from the airpump to the solenoid and then on to the aux ports is something I'm not familiar with. I own series four cars who's aux ports are operated by exhaust backpressure.

Your series five will not, cannot be operated by exhaust backpressure.

That said, if you just have the airpump on the series five car and no ACV conneted to it, just how would that work? No backpressure if the line that was supposed to go from the airpump to the ACV is wide open and connected to nothing. Got me how.
Old 07-14-09, 09:52 PM
  #17  
Full Member

Thread Starter
 
luyo's Avatar
 
Join Date: Oct 2006
Location: Peru
Posts: 83
Likes: 0
Received 0 Likes on 0 Posts
Then I will check the air pump anyway...if I got it or not....

As far as I understand, check the TPS and then wired the ports ( how Do I do that)

*I ask a lot of questions since here in Peru we dont have many mechanics who knows about Rotary
Old 07-15-09, 01:06 AM
  #18  
Are you experienced?

iTrader: (18)
 
jjcobm's Avatar
 
Join Date: Oct 2008
Location: Illinois
Posts: 2,099
Likes: 0
Received 1 Like on 1 Post
Originally Posted by luyo
Then I will check the air pump anyway...if I got it or not....

As far as I understand, check the TPS and then wired the ports ( how Do I do that)
S5 5/6th ports & VDI are controlled through the airpump, acv, and solenoid rack. It goes like this: airpump connects to acv; acv connects to solenoid rack (emissions equipment). No airpump, no 5/6th ports; no acv: airpump is connected to nothing....

If I were in your situation, I would just replace the ACV, unless you want to have it removed for some specific reason and you are sure of what you are doing. It is much simpler than wiring the 5/6th ports and don't forget you have to wire your VDI open also, and on top of this you could have a huge vacuum leak because you removed the ACV and possibly didn't block off the vacuum rack lines going from the ACV to the solenoid rack. Either way, wiring them open will not help drivability. It will only increase performance top end wise and make you power down low (rpm range).

Regardless, if you you must know how to wire them open. remove the 5/6th port actuators. Move the small lever that was connected to the actuator towards the top on both the left and right, now your ports are open. You have to either lightly glue/epoxy them in place or use something to hold them open. Repeat this process for your VDI on the intake, you will see the actuator on there and has to be removed...

Don't forget to block off the vacuum lines for the actuators....

Doing this you have now lost your low end torque, but now you have power again up top.

Good luck.
Old 07-16-09, 10:50 AM
  #19  
Full Member

Thread Starter
 
luyo's Avatar
 
Join Date: Oct 2006
Location: Peru
Posts: 83
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by jjcobm
S5 5/6th ports & VDI are controlled through the airpump, acv, and solenoid rack. It goes like this: airpump connects to acv; acv connects to solenoid rack (emissions equipment). No airpump, no 5/6th ports; no acv: airpump is connected to nothing....

If I were in your situation, I would just replace the ACV, unless you want to have it removed for some specific reason and you are sure of what you are doing. It is much simpler than wiring the 5/6th ports and don't forget you have to wire your VDI open also, and on top of this you could have a huge vacuum leak because you removed the ACV and possibly didn't block off the vacuum rack lines going from the ACV to the solenoid rack. Either way, wiring them open will not help drivability. It will only increase performance top end wise and make you power down low (rpm range).

Regardless, if you you must know how to wire them open. remove the 5/6th port actuators. Move the small lever that was connected to the actuator towards the top on both the left and right, now your ports are open. You have to either lightly glue/epoxy them in place or use something to hold them open. Repeat this process for your VDI on the intake, you will see the actuator on there and has to be removed...

Don't forget to block off the vacuum lines for the actuators....

Doing this you have now lost your low end torque, but now you have power again up top.

Good luck.


Ok I got it, thank you very much, I will see first the TPS and I know now that one mechanic here took off my ACV and he got it (I dont know why he took it off) I will tell him anyway to put it back again and see all the lines correct.

And then theres a possibility that I just wired the ports and VDI (I prefer not but...) If I do this I just understand that I have to glue or try to hold the lever to bottom of the ports and VDI and see all the lines closed, I hope IM right....

Something I checked just now is that when my check light goes on I just put neutral gear and accelerate the rpm till 4000 and the lights goes off, I dont know maybe this can help you guys to figure something out...

Keep writting Im open to different comments....
Old 07-16-09, 12:03 PM
  #20  
Are you experienced?

iTrader: (18)
 
jjcobm's Avatar
 
Join Date: Oct 2008
Location: Illinois
Posts: 2,099
Likes: 0
Received 1 Like on 1 Post
Originally Posted by luyo
And then theres a possibility that I just wired the ports and VDI (I prefer not but...) If I do this I just understand that I have to glue or try to hold the lever to bottom of the ports and VDI and see all the lines closed, I hope IM right....

Something I checked just now is that when my check light goes on I just put neutral gear and accelerate the rpm till 4000 and the lights goes off, I dont know maybe this can help you guys to figure something out...
Well the lever goes UP, so you have to glue/hold them in the up position. The check engine light will alot of the times go away and come back... I am sure you have a vacuum leak, just get the acv installed, your problems should go away and you will have a fully functional car with no check engine light. If you want to start wiring ports open, make sure you block off the corresponding vacuum lines on the spider and intakes for both the acv and the 5/6 & vdi actuators and anything else you see.

By the way, remember that wiring your ports won't solve your problem. You need to either get the acv and associated vacuum lines hooked up and check everything else...........
Old 07-17-09, 05:58 PM
  #21  
Full Member

Thread Starter
 
luyo's Avatar
 
Join Date: Oct 2006
Location: Peru
Posts: 83
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by jjcobm
Well the lever goes UP, so you have to glue/hold them in the up position. The check engine light will alot of the times go away and come back... I am sure you have a vacuum leak, just get the acv installed, your problems should go away and you will have a fully functional car with no check engine light. If you want to start wiring ports open, make sure you block off the corresponding vacuum lines on the spider and intakes for both the acv and the 5/6 & vdi actuators and anything else you see.

By the way, remember that wiring your ports won't solve your problem. You need to either get the acv and associated vacuum lines hooked up and check everything else...........

OK thank you, I will try hard to get ACV back again then,,,

And you told me that the lever goes up when I accelerate?? and since that, I have to holp it up ?? If its that way I will keep in mind , just in case I cant go to ACV back.

thanks
Old 07-17-09, 10:34 PM
  #22  
Are you experienced?

iTrader: (18)
 
jjcobm's Avatar
 
Join Date: Oct 2008
Location: Illinois
Posts: 2,099
Likes: 0
Received 1 Like on 1 Post
the actuators push up on the lever i think around 3800rpm, vdi is a bit later....
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
trickster
2nd Generation Specific (1986-1992)
25
07-01-23 04:40 PM
bb6guy
Old School and Other Rotary
10
10-01-18 08:07 AM
immanuel__7
2nd Generation Specific (1986-1992)
89
09-05-15 10:23 AM
bb6guy
3rd Generation Specific (1993-2002)
3
08-12-15 03:29 PM



Quick Reply: Car little rough, o2 sensor?



All times are GMT -5. The time now is 09:05 PM.