tbourner Posted March 9, 2006 Share Posted March 9, 2006 So, this could be the reason for my bad idle and occasional backfire that I had on Monday!! Could this've been caused by the 2 week old petrol (Tesco 99) I had in my car? It was almost empty and started with huge plumes of black smoke and really lumpy; went and got a Jimmy Can of 99 and put it in and it cleared up - not sure if it was a coincidence though (didn't think fuel would go off that badly!). Question 2: How can I clean it without having any lemon substance in the house (well I've got some fairy liquid!!)? Is it delicate? Link to comment Share on other sites More sharing options...
RICHARDA Posted March 9, 2006 Share Posted March 9, 2006 Fuel should'nt go "off" that quickly. Link to comment Share on other sites More sharing options...
JohnK Posted March 9, 2006 Share Posted March 9, 2006 I often leave tesco 99 for 2 weeks +, never had a problem. Link to comment Share on other sites More sharing options...
tbourner Posted March 9, 2006 Author Share Posted March 9, 2006 Apparently the octane rating reduces though, and with my ECU being used to 99 RON and then getting some dirty low RON stuff shoved through could cause black smoke? Why else would it be smoking, and then suddenly clear up after a restart? Then it was fine for a day, then started misfiring! Anyway - the O2 sensor looks nasty, how do I clean it? then I'll put it back in and start again (After ECU reset?), see how it goes. The sensor was new less than 10k miles ago so should be fine. Link to comment Share on other sites More sharing options...
tbourner Posted March 9, 2006 Author Share Posted March 9, 2006 Anyway - the O2 sensor looks nasty, how do I clean it? Anyone? Can I just run it under the tap or something? Link to comment Share on other sites More sharing options...
Homer Posted March 9, 2006 Share Posted March 9, 2006 Diluted kitchen or bathroom fluid maybe? Anything acidic should do the trick. Link to comment Share on other sites More sharing options...
Kopite Posted March 9, 2006 Share Posted March 9, 2006 Could clean it with vinegar (probs wouldnt do much though)? Or fresh petrol Link to comment Share on other sites More sharing options...
toyotasuprauk Posted March 9, 2006 Share Posted March 9, 2006 That wont be caused by the fuel. Link to comment Share on other sites More sharing options...
Homer Posted March 9, 2006 Share Posted March 9, 2006 That wont be caused by the fuel. Not sure I agree, soot like that is a sign of overfueling. The lumpy idle/off boost roughness is another. Thats a really bad state for a sensor to be in. This is what mine looks like Link to comment Share on other sites More sharing options...
toyotasuprauk Posted March 9, 2006 Share Posted March 9, 2006 It could well be a fueling problem, that I'm not sure about and certainly dont disagree. I meant I dont think its caused by the petrol going off after 2 weeks. Link to comment Share on other sites More sharing options...
Homer Posted March 10, 2006 Share Posted March 10, 2006 I meant I dont think its caused by the petrol going off after 2 weeks. Ah, yes. Totally agree with you there, no way will it be caused due to old petrol. Even if it were 'old' all that means is that the octane rating is down, that won't cause the ECU to dump tons of fuel into the engine and cause overfueling. Clean the sensor, check your plugs are not fouled, reset the ECU and see how it is after 20 miles. Link to comment Share on other sites More sharing options...
tbourner Posted March 10, 2006 Author Share Posted March 10, 2006 It was Brian in my other thread that suggested a fuel issue, I know it loses octane but I said then I can't believe it'd cause this issue! Eyefi said it could be coolant temp sensor or (very unlikely) air temp sensor, possible? The problem is; something went wrong in the 2 weeks it was sitting on my drive in the cold and rain, so when I started it it sooted up my O2 sensor, and now it overfuels because of it. So what would happen in 2 weeks that would cause massive black plumes of smoke for about 1 minute - then get better? Link to comment Share on other sites More sharing options...
Bob Posted March 10, 2006 Share Posted March 10, 2006 I'd have thought brake / carb cleaner spray should be alright Link to comment Share on other sites More sharing options...
Ark Posted March 10, 2006 Share Posted March 10, 2006 Cocacola is viscious stuff, and very good for cleaning apparently. Just don't drink it afterwards. Link to comment Share on other sites More sharing options...
Chris Wilson Posted March 10, 2006 Share Posted March 10, 2006 There's nothing wrong with the colou of the O2 sensor, appearance wise. Renew it if you are doubting if it works right, or get it tested. Link to comment Share on other sites More sharing options...
tbourner Posted March 10, 2006 Author Share Posted March 10, 2006 So what else would cause mild overfuelling? It could be worse when warmed up but that's based on a single test run! How do you test an O2 sensor? And no the OX1 pin doesn't work because it's overfuelling so the ECU has conpensated for any sensor error! Link to comment Share on other sites More sharing options...
JohnK Posted March 10, 2006 Share Posted March 10, 2006 The O2 sensor only effects the fueling on Idle - closed loop, if the problem occurs while in open loop look else where. Link to comment Share on other sites More sharing options...
tbourner Posted March 10, 2006 Author Share Posted March 10, 2006 It's only lumpy on idle, and rough on overrun in gear, so closed loop - symptoms of overfuelling. Link to comment Share on other sites More sharing options...
Chris Wilson Posted March 10, 2006 Share Posted March 10, 2006 Well stop it overfuelling for a start! Link to comment Share on other sites More sharing options...
tbourner Posted March 10, 2006 Author Share Posted March 10, 2006 err.... that's the whole point of this thread - HOW? I think I'll just buy a lemon on the way home. Link to comment Share on other sites More sharing options...
tbourner Posted March 11, 2006 Author Share Posted March 11, 2006 Cleaned, put back in, sounds OK but OX1 is reading between 0.7 and 0.8, occasionally dropping to 0.1 - what do I check now? Link to comment Share on other sites More sharing options...
Recommended Posts
Please sign in to comment
You will be able to leave a comment after signing in
Sign In Now