my jeeps been running rough and there is a strong smell of petrol.i have just changed 5 of the 6 spark plugs [ all 5 of the old ones were black - could not get to the one nearest the radiator ! ]/ new distributor cap and rotor / and 5 new leads. afterall that its still running rough.any jeep mehanics out there with ideas what needs attention ?is it the cat lamda sensor or injectors ? how do you clean the lambda sensors ?the RAC cleaned the distributor before i changed all the above and it seemed to go fine for 20 mins.i also filled up £50 of petrol in wales coming home, could it be dirty petrol ?i also did realised that i ran out of water in my coolant tank before this happened but did top it up.thanks
you can't really clean lambda sensors, you just replace them,its good if you can get oem ones but some jeepers including myself have used the universal ones,give lighthouse a call about them ( you can find their number in the suppliers section)If your jeep is running rich then usually it is down to them, they control all the fueling to the injectors so change them and then run some injector cleaner as well and hopefully it should be sorted.(p.s they can be a complete arse to get out, especially if they haven't had copper grease on the threads when fitted)
Is it intermittant...?
Most likely cause is upstream O2 sensor but the thing should run ok from cold even with the sensor shot to pieces as the PCM doesn't look at it until it's up to temperature.BTW, when you say you ran it out of coolant, did it overheat? They have a habit of melting pistons when that happens. That'd sure make it run rough.
The O2/Oxygen/Lambda sensor you're looking for is in the front downpipe.Do you have a regular misfire on one cylinder or random roughness? It might be worth doing a compression check before changing any more electrical bits.
……the RAC cleaned the distributor before i changed all the above and it seemed to go fine for 20 mins……
I’m surprised the O2 sensor didn’t resolve the problem.Have you checked the air intake system is not blocked with something? What state is the air filter in?The other things to consider are the MAF, TPS, CPS and the downstream O2 sensors. I think you can just unplug the first two (one at a time) and see if this makes a difference at tick-over. You will probably end up with the EML light on on the dash though.Just my 2p worth!