thorburn 121 Report post Posted February 23, 2011 All of this started after it had all been put back together after 6 months of sitting. And a few parts were replaced. Symptoms: - When up to temperature, with low rpms and medium load the car stutters. For example at a constant 50km/h in 4th gear. - When up to temperature the engine shakes under idle and tractor noises from the gearbox start - On full lock at in neutral the car has stalled. I haven't been able to repeat this so it hopefully was a one off. Got a carman diagnostic scanner on it today and i've got fault codes for: - The exhaust valve. This is no longer connected and i'm unsure of what i did with the wires for it. - 1-3 bank oxygen sensor - 4-6 bank oxygen sensor While watching the oxygen sensors in real time they showed a constant 4.5v for some time. Then the 4-6 bank oxygen sensor dropped to 0.5v and the engine started shaking and the tractor noises started. Eventually the the 4-6 sensor returned to 4.5v. Later the 1-3 bank oxygen sensor followed and dropped to 0.5v I'd thought narrow band oxygen sensors only read from 0-1 volts. Is this correct? So the obvious solution seems to be get some new oxygen sensors. I'm just wondering if there is anything else that could be causing this? Quote Share this post Link to post Share on other sites
*Glenn* 854 Report post Posted February 23, 2011 The O2 sensor codes are the result of something else. Air leaks, airmass sensor or over/under fueling Quote Share this post Link to post Share on other sites
thorburn 121 Report post Posted February 23, 2011 Thank you very much Glenn. I've just had a look at a couple of methods for checking leaks. Like using carb cleaner or propane. I'm not so happy about having to get the fire extinguisher out. Are there any other options? I'll take off the intake anyway and see if it's something obvious. I'm guessing the only way of checking a maf sensor is to replace it with a working unit? Fueling problems would be caused by the fuel pressure regulator and/or bad injectors? Quote Share this post Link to post Share on other sites
thorburn 121 Report post Posted February 26, 2011 I think i've fixed it. The vacuum line that goes to the exhaust flap,valve,thing had lost its plug. Or more likely then that I forgot to put it in. I've now sealed over the hole and it runs well again. I do feel pretty stupid Quote Share this post Link to post Share on other sites
