MIXTURE TOO RICH- HELP!!

vinceboy

Hi all. My car just started misfiring badly, had a very near miss pulling out of a junction, engine management flashed on and off a few times. Checked my plugs and they were totally black. Have cleaned em and car runs a bit better but still misfires now and again. Recently put forte gas treatment in tank like i usually do. Car is an auto and done 52k. Any ideas would be appreciated.

JohnnyN

Hello mate and welcome to the site. It might be worth considering getting the car wired up to Tech 2 to see what codes have been stored. Alternatively you may want to change the upper lambda sensor that controls the air/fuel ratios. The upper sensor is around £72 from Vauxhall or you can find them on ebay.

vinceboy

Thanks for that, but is there anything else i can try that dont involve spending loads. Car stalled today for the first time in 2 years, didnt think automatics could stall, in fact ive been driving autos for 10 years and this is the first one that has done this. Will a faulty lamda sensor still cause this and is there any point in me changing simple items like the fuel filter as ive read that if u use a fuel flush youre filter sometimes gets blocked. I only drive 3 miles a day if thats any help.

JohnnyN

Start with the basic bits by all means. The fuel filter has been in question before, only just recently i've read a thread on here about that. The thing is, the fact that you've mentioned that your spark plugs are black would indicate too much fuel going in and not the oppposite.

MikeS

unplug the front lambda and take her for a drive

the harness should be hooked up next to the egr valve down the side of the head - blue square shaped connector

if that doesnt work then hook it back up and then try unplugging the coolant temp sensor that is located back of the head next to the stat and take her for a spin

vinceboy

will try all those things, thanks. Just thought id mention b4 this started the car was serviced from main dealer, just an oil and filter change (what a rip off) and on the invoice they used 5.5 units of oil at 1 litre per unit. I did about 50 miles like this b4 draining some out. Whenever ive done a service b4 i always have some left out of a 5l can and they used 10w/40, whereas normally I use 5w/30. Could this overfill have caused this problem or is it just a coincidence?