JohnGNixon Posted January 10, 2019 Share Posted January 10, 2019 The car is a 2002 ford focus 1.6 petrol. last week noticed that I could smell the CAT (sulphur) but it went and the car was running ok. Today, the idle has gone weird! If I take my foot off the juice it idles at 2500 RPM for about 30 secs then drops to 1400 RPM. This happens everytime I touch the accelerator. The car drives ok otherwise. There are no warning lights and my OBD scanner shows no codes. I can find no vacuum leaks or loose wiring. Any idea where to start? It has been suggested that it might be a failed O2 sensor or the MAF sensor. How can I check? Quote Link to comment Share on other sites More sharing options...
JohnGNixon Posted January 14, 2019 Author Share Posted January 14, 2019 I have looked and checked for any connection problems and can find nothing. The car runs perfectly other than the idle problem. Really don't know where to look, any advice at all appreciated. Quote Link to comment Share on other sites More sharing options...
TomsFocus Posted January 14, 2019 Share Posted January 14, 2019 It looks like you've checked all of the obvious things. Though I'd check the throttle body as well tbh. Next step would be getting proper Ford diagnostics on it, Forscan would be ideal. Quote Link to comment Share on other sites More sharing options...
Micro Posted January 14, 2019 Share Posted January 14, 2019 1 hour ago, TomsFocus said: It looks like you've checked all of the obvious things. Though I'd check the throttle body as well tbh. Next step would be getting proper Ford diagnostics on it, Forscan would be ideal. I wonder if his code scanner will show live data. Checking the Short Term/Long Term fuel trims, and also the O2 sensor values would give a wealth of information. Quote Link to comment Share on other sites More sharing options...
JohnGNixon Posted January 15, 2019 Author Share Posted January 15, 2019 My scanner shows some live data but not fuel trims (whatever they are!) it does however say that it couldn't check the status of the CAT due to an open loop (I think) though there are no DTC codes and the engine check light stays off. Quote Link to comment Share on other sites More sharing options...
JohnGNixon Posted January 15, 2019 Author Share Posted January 15, 2019 On 1/14/2019 at 1:29 PM, TomsFocus said: It looks like you've checked all of the obvious things. Though I'd check the throttle body as well tbh. Next step would be getting proper Ford diagnostics on it, Forscan would be ideal. TBH I was hoping to avoid Ford diagnostics as I imagine it to be very expensive and my student grant will only stretch so far! Quote Link to comment Share on other sites More sharing options...
TomsFocus Posted January 16, 2019 Share Posted January 16, 2019 17 hours ago, JohnGNixon said: TBH I was hoping to avoid Ford diagnostics as I imagine it to be very expensive and my student grant will only stretch so far! Forscan is free... The adapater only costs about £15 and I assume you already have a laptop or smartphone. 1 Quote Link to comment Share on other sites More sharing options...
TomsFocus Posted January 16, 2019 Share Posted January 16, 2019 19 hours ago, JohnGNixon said: My scanner shows some live data but not fuel trims (whatever they are!) it does however say that it couldn't check the status of the CAT due to an open loop (I think) though there are no DTC codes and the engine check light stays off. Did you check this when cold? 'Open loop' means the engine is running on a preset map without the lambda sensor feedback - it does this when cold as normal, but if the engine was warm and it was still running in open loop you may have a lambda fault. 1 Quote Link to comment Share on other sites More sharing options...
JohnGNixon Posted January 16, 2019 Author Share Posted January 16, 2019 1 hour ago, TomsFocus said: Forscan is free... The adapater only costs about £15 and I assume you already have a laptop or smartphone. Oh I see. I assumed Forscan was the Ford system that they use. I have an OBD adaptor that I read on my phone or laptop. I'll look into it. Thanks. Quote Link to comment Share on other sites More sharing options...
JohnGNixon Posted January 16, 2019 Author Share Posted January 16, 2019 (edited) 1 hour ago, TomsFocus said: Did you check this when cold? 'Open loop' means the engine is running on a preset map without the lambda sensor feedback - it does this when cold as normal, but if the engine was warm and it was still running in open loop you may have a lambda fault. Hot or cold is the same. I'll have to look up how to test the lambda sensors, there is one pre and post cat. I think my adaptor is an ELM 327 which should work. I use Torque on my phone. I'll download Forscan and try it when the rain stops!! Thanks. Edited January 16, 2019 by JohnGNixon Addendum Quote Link to comment Share on other sites More sharing options...
DJ_Andy_M Posted January 17, 2019 Share Posted January 17, 2019 2002 Focus has the Zetec engine. Have you taken your idle control valve off and given that a clean? These used to be notorious on the Escort for causing this issue! Quote Link to comment Share on other sites More sharing options...
JohnGNixon Posted January 17, 2019 Author Share Posted January 17, 2019 Yes I have and it made no difference. I have now installed the Forscan software and it is a good piece of kit, thanks. I would be obliged if I could draw on your collective experience in interpreting the results. Fuelsys1 shows closed loop, bank 1, which I think is ok and applies to the pre-cat sensor (green) but fuelsys2 shows as error on bank 2 , I think this refers to the post-cat sensor (blue) see pics. Am I reading this right? If this is the only thing I will be a happy guy! There is still no engine check light and no DTC detected by Forscan. Thanks for you time guys, I really appreciate it. Quote Link to comment Share on other sites More sharing options...
JONATHAN_11_80 Posted January 18, 2019 Share Posted January 18, 2019 Hi, A high idle and a sulphur smell usually means it's running lean. A vacuum leak could be your issue. Quote Link to comment Share on other sites More sharing options...
JohnGNixon Posted January 18, 2019 Author Share Posted January 18, 2019 (edited) I did look for a leak but I note the tail pipe is a little sooty rather than running lean. Also, the car drives perfectly well, no loss of power etc. It's just the very high idle that is troubling me. Edited January 18, 2019 by JohnGNixon Addendum Quote Link to comment Share on other sites More sharing options...
JohnGNixon Posted January 24, 2019 Author Share Posted January 24, 2019 The problem continues! The Forscan diagnostics showed an error in fuelsys2 (see above) so I changed the secondary O2 sensor but this has made no difference at all. For good measure I have also removed, cleaned and checked the throttle body and idle by-pass valve too. I'm completely stumped now. Quote Link to comment Share on other sites More sharing options...
Micro Posted January 24, 2019 Share Posted January 24, 2019 I don't believe I have a Bank 2 on my engine (4 cyl 1.6 Sigma), hence why it may show an error - you haven't got a bank 2!. Your throttle position is at 18%, have you put your Accelerator pedal position data in too, to ensure it's not a faulty accelerator pedal? There may be two data items for the pedal - one going positive and one negative. Quote Link to comment Share on other sites More sharing options...
JohnGNixon Posted January 24, 2019 Author Share Posted January 24, 2019 (edited) Thanks but from what I read bank 1 refers to the O2 sensor before the CAT and bank 2 refers to the one after. I don't think it's the pedal as the throttle butterfly opens and closes without sticking and there is no binding of the cable. Everything appears as it should be which is why I'm so baffled. The car starts and drives well other than this idle problem. I'm getting desperate now as my son is supposed to be taking his test in this car next week. Also, is 18% bad? Do you know what it should be at idle? Goggle doesn't seem to know! Edited January 24, 2019 by JohnGNixon addition Quote Link to comment Share on other sites More sharing options...
Russ Posted January 25, 2019 Share Posted January 25, 2019 Had a look on an RAC site and someone with the same problem said they managed to fix it on their focus by replacing the Crankcase pipe behind the throttle body? (They said it was a bit difficult to see but never said if the pipe was collapsed or split) just a suggestion Quote Link to comment Share on other sites More sharing options...
JohnGNixon Posted January 25, 2019 Author Share Posted January 25, 2019 Thanks Russ, I'll check this out too but it was replaced only last year. Quote Link to comment Share on other sites More sharing options...
JohnGNixon Posted January 26, 2019 Author Share Posted January 26, 2019 CASE CLOSED! I turned my attention to the TPS. Removed it to see if it needed cleaning etc but when it was off it was obvious that it is a sealed unit with no access to the internal parts so I just put it back and everything is now fine! Must be about to fail so I am replacing it. What a pain, something so small causing me such a headache. I suppose we live and learn. Many thanks to all who offered advice, it was much appreciated. 1 Quote Link to comment Share on other sites More sharing options...
FatHead1979 Posted February 11, 2019 Share Posted February 11, 2019 On 1/26/2019 at 10:08 AM, JohnGNixon said: CASE CLOSED! I turned my attention to the TPS. Removed it to see if it needed cleaning etc but when it was off it was obvious that it is a sealed unit with no access to the internal parts so I just put it back and everything is now fine! Must be about to fail so I am replacing it. What a pain, something so small causing me such a headache. I suppose we live and learn. Many thanks to all who offered advice, it was much appreciated. Thanks for posting back with a resolution, it might help someone else in the future. Quote Link to comment Share on other sites More sharing options...
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