misfiring on tickover

240dl estate 1990,twin choke down draught solex cisac carburetor,some type of sensoring of exhaust as pipe from exhaust goes to valve under carb then to inlet manifold.this vehicle was originally fitted with a cat,no sensor on cat.when exhaust had to be replaced i did so without the cat,from the time the exhaust pipe broke the engine misfired on tickover,number 2cylinder,all checks on plugs,leads and compression have yielded nothing,any suggestions appreciated..brin65

Unfortunately......

You've ommitted the key item to the problem....The Lambda Probe!!The car needs this to adjust the mixture according to the amount of co in the exhaust. This is why when by passing the cat the lambda probe IS required to maintain the original values that the car is set to.

Buy a new lambda probe and a bypass pipe with a "pop" for the probe to be installed, then reconnect and all will return to normal :D

Trust me ....}(

Regards
Dave M

thanks for the comments,where do i find the lambda probe?a drawing would be helpful,thanks again..brin65

The lambda probe is usually located on the exhaust side of the car, normally on the actual first section of the exhaust where the cat used to be. In that section there would have been what is called a piping "Pop" which would look like a very small "T" junction on a large exhaust. The lambda probe comes either three wires or two, and the sensor screws into this "T" the wires SHOULD travel down the bulk head on the exhaust side and just out of sight, underneath the car - to meet the probe. You're now going to have to find these and see if you can get a proper bypass pipe made up to fit, then purchase a lambda probe from Eurocarparts (£25 - £35) and refit and connect it all back up.

Don't worry, you're not reinstalling a "Cat" all you're doing is putting a pipe in + a sensor.


Regards
Dave M

P.S If you want, and can provide pictures, you can Email me on

DaveMorton@Blueyonder.co.uk

The "type of sensoring of exhaust as pipe from exhaust goes to valve under carb then to inlet manifold" is the EGR or the Exhasut Gas Recirculation, i.e. exhaust gases that go back into the inlet. Ditch this.

George

Anglo-Swede resident near Leuven in Belgium

'87 745 GLE Turbo Diesel Intercooler (D24TIC/M46, 200k)
'88 745 Turbo Intercooler (B230ET/M46, 270k)
'88 745 GL (B200E/M47, 200k)
'89 440 GL (B18K/M55, 90k)

thanks for your comments,and everybody elses,ther was never any type of probe or sensor fitted to the cat,as i have been aware of problems occuring when the cats that have sensors have been ditched,this engine is fitted with numerous fine bore coloured pipes that run back and forth from inlet manifold,carburetor,and a round black vacum looking sensor[like a washing machine pressure switch]which is bolted to the inside wing in the engine compartment,if anyone is struggling with my attempt to explain i will endeavour to take a photo,anything to make life easier ,,,,thanks again hope this may shed some light from someone....brin65