| Porsche Enthusiasts Club Forum https://forums.tipec.net/ |
|
| MOT failure - advice and help? Now PASSED but a query... https://forums.tipec.net/viewtopic.php?f=25&t=8722 |
Page 1 of 1 |
| Author: | doctor924 [ Wed Jun 09, 2010 2:36 pm ] |
| Post subject: | MOT failure - advice and help? Now PASSED but a query... |
HI All, Submitted my 944 2.7 project for MOT this morning and it failed - but not on too much and given it stood for 4 years or so and I've replaced the sills etc - I was quite pleased. Failure points were: Illegal front and back number plates (!) n/s front brake binding (probably a good run would sort this) A couple of non functioning lights - again probably corroded connectors and...emissions. I had 6% CO whereas the legal limit is 3.5% Reading on this forum and others - a good 944 should achieve around 2% CO content/volume I've read that the usual problems of running rich are: Failed/failing DME temp sensor Worn AFM Plug leads Spark plugs and of course air filter Are there any other causes? Car had a FSH before layup and it looks like the plugs were very new, Plug leads are unknown (a bit nibbled by rodents though!) Air filter new. Car idles and starts fine - it does feel hesitatnt when running on the road - likes it is running rich. Is the AFM an easy fix? clean? inspect? I have Clarks Garage guide to the AFM but any/all advice welcome! Thanks Ian |
|
| Author: | sulzeruk [ Thu Jun 10, 2010 7:44 am ] |
| Post subject: | Re: MOT failure - advice and help? |
Ian, if it is miles out, it is probably the AFM. What is the Bosch number of it and I will see if I have a spare one here? Are you getting a bit of black smoke out the back when you first start up from cold? Alasdair |
|
| Author: | doctor924 [ Thu Jun 10, 2010 11:04 am ] |
| Post subject: | Re: MOT failure - advice and help? |
Can you say that being 6% CO content/volume (i.e. 100% more than legla max and 150% more than expected) is way out - then I guess the AFM is a suspect. Would the car having stood for a long time (4 years or so) have a bearing on the performance of the AFN? I'll check part numbers but it is for an 89 2.7 model. Thanks for the reply! Ian |
|
| Author: | doctor924 [ Thu Jun 17, 2010 9:33 am ] |
| Post subject: | Re: MOT failure - advice and help? Now PASSED but a query... |
HI Retested my 944 this morning and it passed. However, the emissions (CO) was now down at 0.2% which seems far too lean. To adjust the previously high emissions (running rich condition) - I replaced the following parts (as per 2.7 parts codes): DME temp sensor The MAF unit New air filter Previously during the resto on the car, I had changed the injectors for reconned ones for the 2.7 engine. In hindsight, looking at the old MAF, the mixture screw had clearly been adjusted, so I guess its possible that the mixture had been enriched then to account for original faltering injectors(?). Anyway the MAF unit I installed still had the tamper proof plug installed so i assume it was still factory set. So- 0.2% is too lean I think and the engine was running a little warm too - what are folks thoughts on here? Tweak the MAF mixture a bit to enrich the mixture? Tnanks for thoughts Ed |
|
| Author: | tr7v8 [ Thu Jun 17, 2010 10:50 am ] |
| Post subject: | Re: MOT failure - advice and help? Now PASSED but a query... |
doctor924 wrote: HI Retested my 944 this morning and it passed. However, the emissions (CO) was now down at 0.2% which seems far too lean. To adjust the previously high emissions (running rich condition) - I replaced the following parts (as per 2.7 parts codes): DME temp sensor The MAF unit New air filter Previously during the resto on the car, I had changed the injectors for reconned ones for the 2.7 engine. In hindsight, looking at the old MAF, the mixture screw had clearly been adjusted, so I guess its possible that the mixture had been enriched then to account for original faltering injectors(?). Anyway the MAF unit I installed still had the tamper proof plug installed so i assume it was still factory set. So- 0.2% is too lean I think and the engine was running a little warm too - what are folks thoughts on here? Tweak the MAF mixture a bit to enrich the mixture? Tnanks for thoughts Ed Yup tweak the screw to get around 1.8%-2.0% It should be a bit more economical as well. PS what was the issue with the plates? |
|
| Author: | doctor924 [ Thu Jun 17, 2010 10:56 am ] |
| Post subject: | Re: MOT failure - advice and help? Now PASSED but a query... |
Number plates - to quote from the failure sheet: "Front/rear - registration plate background overprinted or shadowed with text" The plates had the porsche badge on the first inch or so and '944' in repeated light colour in the background as a watermark style feature.... Anyway - just got new plates made up CHeers Ed |
|
| Author: | tr7v8 [ Thu Jun 17, 2010 12:32 pm ] |
| Post subject: | Re: MOT failure - advice and help? Now PASSED but a query... |
doctor924 wrote: Number plates - to quote from the failure sheet: "Front/rear - registration plate background overprinted or shadowed with text" The plates had the porsche badge on the first inch or so and '944' in repeated light colour in the background as a watermark style feature.... Anyway - just got new plates made up CHeers Ed Me thinks I'll be changing mine before the MOT & change them back afterwards then... |
|
| Page 1 of 1 | All times are UTC |
| Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group http://www.phpbb.com/ |
|