[chrisg05]

I will try that when I get home and see if it is rubbing.. ..I actually experenced bucking last night again.. o2 sensor lasted 1 year.. ugghhh

 

[Bob Lincoln]

A tip on O2 sensors: they have a packet of anti-seize compound supplied with them. If you get any at all on the tip of the sensor, it will ruin it very quickly - corrosive sulfur.

And if some other condition caused the sensor to fail, until it is corrected, it will continue to ruin perfectly good sensors.

 

[B10alia]

What brand of sensor do you usually buy? People have reported problems with Bosch.

 

[Bob Lincoln]

I never had any performance issues with Bosch. Last one ran 110K miles before I scrapped the car, was still good. Again, I think most of them have the issues above.

Having said that, the Bosch sensor is about 1/8" taller than the OEM size, and an O2 sensor socket won't fit over the entire sensor and its wiring. This causes rounding off of the hex at the manifold. I have a spare engine with one that's trapped, and will have to figure out how to get it out. So I use Denso or NTK, but only for that reason.

 

[chrisg05]

I bought denso.. thought it was a good brand.. if I could get mopar I would. The funny thing is that it never throws a 51 or 52. It does not throw any codes. I know the computer on this car was replaced by the former owner. All I know is that it gets fustrating

 

[Bob Lincoln]

Denso is a premier brand, it and NTK are used as OEM.

Your problem is not the O2 sensor if there are no codes.

 

[chrisg05]

well the symptions are stumbling and bucking while warmed up. When the engine is "cold" it is fine.. does not stumble much.. but after about 15 min of driving .. i feel like I am on a roller coaster with the bucking...gas millage has gone down considerably from 27mpg to like 13mpg. Switched the map sensor today just to see if it was that .. but the same with both of them. There is vaccum on the line..

I am really beginning to wonder if it is the computer. just to check I left the o2 sensor disconnected for 15 min while running it. There was no change in the way it ran but the computer never registered the code. I would assume it would by then.

 

[John Wood]

well the symptions are stumbling and bucking while warmed up. When the engine is "cold" it is fine.. does not stumble much.. but after about 15 min of driving .. i feel like I am on a roller coaster with the bucking...gas millage has gone down considerably from 27mpg to like 13mpg. Switched the map sensor today just to see if it was that .. but the same with both of them. There is vaccum on the line..

I am really beginning to wonder if it is the computer. just to check I left the o2 sensor disconnected for 15 min while running it. There was no change in the way it ran but the computer never registered the code. I would assume it would by then.

By disconnecting the O2 sensor and running it for 15 minutes, you ran the car in what is called "open loop", meaning that the computer did not have full control of the fuel mixture. If the engine continued to buck, I'd guess that you have more of a fuel delivery problem such as a pump thats cutting out after it warms up, or a bad injector, or a clogged filter. I recall 1 post where a bad injector caused a similar problem. I'd try a used injector from a bone yard first if that is possible.

 

[chrisg05]

john.. I appreciate your reply. I replaced the injector already last year but it does not hurt to take a look at it again. I disconnected the o2 sensor just to see if I can get the computer to throw the code 51. For some reason it will not throw that code.

I did however do a tune up on it about 3 weeks ago which consisted of the following replacements

1) air filter
2) oil change
3) new distributor cap
4) new rotor
5) new plugs
6) switched the wires around so the other side can be used

I used parts that I got out of advanced auto along with copper plugs as these engines do not like platnum. they were gapped properly and everything. I used autolites for the plugs

 

[Bob Lincoln]

Did you set the ignition timing to 12 degrees BTDC with the CTS disconnected per the procedure?

 

[chrisg05]

Bob I did.. and I reset the computer afterwards. There was no change in the running of the car

I thought about it and figured that maybe it was an electrical issue to the sensor. I pulled the air cleaner assembly and just traced out the harness. I saw that it went on the back of the valve cover and connected at another point into the main. I then unplugged it there, unplugged it at the sensor and noticed the ground to the block. I removed that bolt brought the harness inside and started testing the wires for breaks with a meter. All the wires checked out but the ground which I crimped down harder onto the eyelet connector. Tested and it worked.

Cleaned the surface and put it all together .. no more stumbling! ran it for aprox 10 min and no more stumbling.. I was thinking of dropping some soder on it .. but not sure if it would hold up to the heat in the bay.

Problem solved.

by the way .. I checked the clearence between the struts and the wheel well.. there is room but not alot. I dont see any scrapes or any obvious rubs. I am going to bring it to a good mechanic that a friend recommeded here in ny just to see what it could be..much quieter since I changed those bushings

 

[John Wood]

Good information on the electrical issue. Thanks for the report and good job troubleshooting. That ground failure is a somewhat common issue as I've had to replace that ring lug on both of my EEKs, and I just re-crimped a new lug on after cutting off the old one off.