Gazztop Posted January 6, 2023 Share Posted January 6, 2023 I have a 2003 Ford KA 1.3 and it has a slight missfire the EML light is on and it's scans PO171 code (system to lean bank1) anyone else had this problem? Quote Link to comment Share on other sites More sharing options...
Gazztop Posted January 7, 2023 Author Share Posted January 7, 2023 Has this car got a maf or map sensor as I can't seem to locate a maf sensor on the throttle body Quote Link to comment Share on other sites More sharing options...
TomsFocus Posted January 7, 2023 Share Posted January 7, 2023 1 hour ago, Gazztop said: Has this car got a maf or map sensor as I can't seem to locate a maf sensor on the throttle body Just a MAP sensor on the back of the intake manifold. There's probably a vacuum leak somewhere causing the lean fault though. Quote Link to comment Share on other sites More sharing options...
Gazztop Posted January 7, 2023 Author Share Posted January 7, 2023 I have tested for a vacuum leak and found nothing car is fine till it fully warms up then missfires Quote Link to comment Share on other sites More sharing options...
TomsFocus Posted January 7, 2023 Share Posted January 7, 2023 4 minutes ago, Gazztop said: I have tested for a vacuum leak and found nothing car is fine till it fully warms up then missfires Ah ok. Sounds more like a coil pack fault if it's worse when warm. Do you have any lambda faults or exhaust leak ahead of the lambda sensor? Quote Link to comment Share on other sites More sharing options...
Gazztop Posted January 7, 2023 Author Share Posted January 7, 2023 It's showing a P0171 fault code so just trying to rule things out checked for vacuum leak and cleaned out throttle body looking at the MAP sensor next Quote Link to comment Share on other sites More sharing options...
TomsFocus Posted January 7, 2023 Share Posted January 7, 2023 8 minutes ago, Gazztop said: It's showing a P0171 fault code so just trying to rule things out checked for vacuum leak and cleaned out throttle body looking at the MAP sensor next The only input the ECU has to detect a lean mixture is lambda. If there are definitely no vacuum leaks around the intake, looking for leaks around the exhaust (dragging extra oxygen past the sensor) is the next thing I'd be doing. Quote Link to comment Share on other sites More sharing options...
Gazztop Posted January 7, 2023 Author Share Posted January 7, 2023 Ok thanks but which sensor it has 2 I believe on the exhaust the first one has been replaced before I bought the car Quote Link to comment Share on other sites More sharing options...
Gazztop Posted January 7, 2023 Author Share Posted January 7, 2023 Would a dirty/ defective MAP sensor not give a lean mixture? Quote Link to comment Share on other sites More sharing options...
TomsFocus Posted January 7, 2023 Share Posted January 7, 2023 25 minutes ago, Gazztop said: Ok thanks but which sensor it has 2 I believe on the exhaust the first one has been replaced before I bought the car The first one reads the fuel mixture. The second one calculates cat efficiency. The sensor itself isn't necessarily faulty though, if there's any leaks around the exhaust manifold, that can affect the readings. 21 minutes ago, Gazztop said: Would a dirty/ defective MAP sensor not give a lean mixture? It could do. Definitely worth a clean as a quick and cheap thing to do. But I wouldn't go to the expense of replacing it without having checked for exhaust leaks first. Quote Link to comment Share on other sites More sharing options...
Gazztop Posted January 7, 2023 Author Share Posted January 7, 2023 Ok many thanks will have a look round the exhaust manifold but it certainly don't sound like it's blowing,again many thanks for the info much appreciated gazza 1 Quote Link to comment Share on other sites More sharing options...
anon Posted January 7, 2023 Share Posted January 7, 2023 If it isn't using oil or water, I would stick a bit of injector cleaner through it (a bottle of redex to five gallons to get it cleaned out.) If the problem persists, I would remove the sparking plugs and see if any were lean. That can often be easier said than done on a Duratec. Acetone and ATF is the best penetrant and it will take repeated applications over a weekend if they are stubborn. Quote Link to comment Share on other sites More sharing options...
Gazztop Posted January 7, 2023 Author Share Posted January 7, 2023 I have changed the plugs and they seemed ok to look at I didn't find it that difficult only the one under the coil pack but a UJ on the socket spanner sorted that 😃 Quote Link to comment Share on other sites More sharing options...
anon Posted January 8, 2023 Share Posted January 8, 2023 That suggests that somebody else had the same problem because those taper fit plugs are notorious for being irremovable. Clean out the injectors, check the valve clearances to ensure that one hasn't gone tight and carry out a compression test. If all is well, I would have the lambda sensors measured and finally change the coil pack.I would also ensure that the fuel filter had been changed. Misfires are best found on test equipment. Guesswork is expensive so check the routine stuff has been done first 1 Quote Link to comment Share on other sites More sharing options...
Gazztop Posted January 8, 2023 Author Share Posted January 8, 2023 I have changed the fuel filter and air filter are the valve clearance hydraulic on these engines? Quote Link to comment Share on other sites More sharing options...
anon Posted January 8, 2023 Share Posted January 8, 2023 Early cars had an old but sound OHV motor. Yours is overhead cam. Ford had a policy of changing names for engines every three weeks which can bring about confusion. Yours has hydraulic tappets so it should be fine. My guess is injection but it is only a guess so I would rule out the easy fixes first, as you seem to be doing. Coil packs fire two plugs at a time so a failure of the coil pack would give a pronounced roughness and if the plugs look good, it is unlikely to be in the ignition system. Quote Link to comment Share on other sites More sharing options...
Eric Bloodaxe Posted January 8, 2023 Share Posted January 8, 2023 Difficult to work out if the symptoms are the same (and remember after all this time!) but we had an issue with the Mrs's 2005 Mk 1 Ka which was only apparent after fully warming up - erratic/fast tickover, slight misfire. Dealer changed oxygen sensor under warranty and that sorted it. Quote Link to comment Share on other sites More sharing options...
anon Posted January 8, 2023 Share Posted January 8, 2023 I am inclined to agree subject to the exhaust being completely sound. My Mk1 2008 model ran 85,000 miles in five years without any problems. I serviced it myself after year one and it was cheap and easy to own. A nearly twenty year old Lambda sensor is probably past its best by now. Quote Link to comment Share on other sites More sharing options...
Gazztop Posted February 26, 2023 Author Share Posted February 26, 2023 Just had diagnostic check done on my KA nothing was found but still missfires when hot, just put some redex in the tank see if that helps Quote Link to comment Share on other sites More sharing options...
Oriskany Posted March 3, 2023 Share Posted March 3, 2023 Are you using NGK plugs? Try swapping them for Bosch - my 1.3 Duratec Ka had the same symptoms and swapping the plugs for Bosch worked for me - the NGKs seemed to run too cold and sooted up with a thin layer of carbon which interfered with the spark but the Bosch plugs seem to run hotter and don't have this feature. Good luck. Quote Link to comment Share on other sites More sharing options...
Gazztop Posted March 9, 2023 Author Share Posted March 9, 2023 The plugs are new not sure if they are NGK ones Quote Link to comment Share on other sites More sharing options...
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