I have a 1992 XJ6 , 4ltr. starts immediately, but wont idle properly , wants to quit . I have to increase rpm to above 1000 , and after it warms...

I have a 1992 XJ6 , 4ltr. starts immediately, but wont idle properly , wants to quit . I have to increase rpm to above 1000 , and after it warms up a bit , it stabilizes a little and then I can move it , but it still wants to surge after a long run. I can overcome this going forward , but backing is very embarrassing. Last run out the Check engine light came on while driving. The VCM gives a code 26, referring to oxygen sensor circuit. Looking in my Haynes repair manual the ECU receives feedback from the sensor, and regulates the fuel delivery. Can I disconnect the sensor ? Thanks for your help and any suggestions. Murray.

Hello again Relly

How are you ?

I was not happy with your answer to my problem , because you seem to think my car has a carberator , which would have a throttle body, however this engine has  6 fuel injectors. . I dont feel I should pay you for your 1st answer, but will give you a second chance .

regards

Murray

Hello Relly

You keep refering to the  cleaning the throttle body.  There isnt any. period.

I checked all the spark plugs , they are like new , I checked the Distributor cap and rotor , they are good . My trouble is with the idle and surging  at low rpm . The engine idles at 750 rpm normally , but now the rpm drops revs below that and would quit  if i didnt work the accelerator.  Sounds to me like it starves for fuel (fuel pump ) or the Ecu is picking up an incorrect message.

OK Relly,  I will try an get in touch  a mechanic of mine and see if he has an OBD scan tool. 

I will get in touch with  you  later, after I reach him. Thank you

Murray.

Relly De Jesus

Good Day Relly, how are you ?

I just want to say that the solution to my idling problem is fixed due to your expert analysis. Thank you very much . It took me 4 hours to remove and replace the air filter , MAF housing , and the hose to the throttle body , and disconnect the  sensors etc. I was going to remove the throttle body , in order to do a proper cleaning of it , but I found it impossible to reach the right lower nut , of the 4 holding it to the manifold , ( without taking the intake manifold apart) , so I sprayed in the carb cleaner as you suggested , and wiped the inside until I was satisfied that it was as clean as I could get it , there was quite a bit of 'crud'  in there , causing the poor idling problem ,as you said . Most of the time spent was trying to get the crazy air filter arrangement off, and back on. certainly not one of Jaguar's better ideas !! Thank You again , "You nailed it ," as they say , and I would like to reward you . I am extremely happy to drive the old cat again with out the embarrassing loping at low RPM.

Hey Relly , how are you ?

Like I said in my last post to you , the car idled fine when I first started it, But later after I got it up to the right eng temp. ,it went up and down  in RPMs & the same problem started again. By the way , the Jaguar on board analized ( VCM) shows a code 26, and that refers to the Oxygen sensor circuit, and further refers to 'lean exhaust/vaccum leak'. Do you have any other fix in mind ?

Thanks

Murray

Hey Relly

Sorry to keep you waiting , but I was at my doctors , and then made supper. I will Check to see if I missed connecting or tightning any hoses , and contact you tomorrow , okay?

Thanks

Murray.

Hey Relly

I just checked to see if I missed connecting or tightening any hose. Everything seems okay, but I noticed a small 'Lucas' hsg. (nbr.on it 13377) bolted to the intake , which has an electric connector on one end with a name tag printed with the word 'IDLE', and on the other end a 1inch hose running to the air intake plastic elbow , which connects to the throttle body via 4" rubber sleeve. Close to the front of the engine there is another 'Lucas' item (nbr. 73377) which is connected to the fuel rail, and has a small vaccum hose directly down to the manifold and another going down underneath the air cleaner hsg. As you know I had the air cleaner off , and the MAF,  which connects to this elbow into the throttle body, all fitted and clamped together. They all seem to be fastened properly , but I could have missed something.  Tks. Murray

Hello Relly

I am still having start up idling problems with the Jaguar. I have to keep working the accelerator pedal as it wants to quit. After a few minutes it will gradually idle at the proper RPM although not as smooth as I would like.

the VCM is giving me a 26 fuel code