Technical Forums» Technical / Performance» no cold start intermittent missfire
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Lx_Micra » CMF Member sydney Australia Member since:  Posts:  |
no cold start intermittent missfire |
Thu 02 May 2013 04:46:35 PM |
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The car wont start when cold once it starts up runs normal. When warmed up starts no problem. when driving normal car runs fine but when i give the gas harder the car seems to miss a beat here and there not always.
ive recently done the head gasket and ive changed injectors and alternator and new battery maybe ive bumped something while doing all this. |
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frank2 » CMF Member birmingham United Kingdom Member since: Posts: |
Re: no cold start intermittent missfire |
Thu 02 May 2013 04:59:48 PM |
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coolant temp sensor readings ok ? lambda readings ?
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Lx_Micra » CMF Member sydney Australia Member since: Posts: |
Re: no cold start intermittent missfire |
Thu 02 May 2013 08:45:32 PM |
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lambda sensor i have a spare one at work and am going to swap that tomorrow the coolant sensor haven't checked resistance but the plug was on. i will try do that aswell i had trouble getting the plug of with out pulling things of to get to it easier before dark.
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Lx_Micra » CMF Member sydney Australia Member since: Posts: |
Re: no cold start intermittent missfire |
Fri 03 May 2013 06:22:29 PM |
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ok plugged in the spare lambda sensor made no difference (spare was working when i removed it so i assume its still good). unplugged the coolant sensor cant get to it with my multimeter so i grabbed a 2.6K ohm resistor and placed it over the two pins on the socket made no difference.
Is there a better way to test this or could it be something else? |
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frank2 » CMF Member birmingham United Kingdom Member since: Posts: |
Re: no cold start intermittent missfire |
Sat 04 May 2013 03:26:16 AM |
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the lambda readings while driving will tell you if the coldstart enrichment is working ok, and if the ecu is closed looping ok (valuable maf/cts/lambda/injector diagnosing info)
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Lx_Micra » CMF Member sydney Australia Member since: Posts: |
Re: no cold start intermittent missfire |
Thu 05 Mar 2015 06:00:59 PM |
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Hey Guys
I Havent been using the car too much so ive put up with the problem i have a bit of time this weekend and wouldnt mind trying to get this fixed. It seems to me like it might be losing fuel pressure over night therefore when trying to start an airlock is created so after cranking for a bit it starts up. If this sounds far fetched tell me. How do i do this lambda readings test? |
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frank2 » CMF Member birmingham United Kingdom Member since: Posts: |
Re: no cold start intermittent missfire |
Thu 05 Mar 2015 06:40:24 PM |
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yes very :)
the middle wire on the lambda creates a voltage when hot, so a voltmeter from there to an earth somewhere |
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Lx_Micra » CMF Member sydney Australia Member since: Posts: |
Re: no cold start intermittent missfire |
Thu 05 Mar 2015 08:08:33 PM |
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ok will try get that done tomorrow and i will post up a video hopefully on a dropbox link.
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Lx_Micra » CMF Member sydney Australia Member since: Posts: |
Re: no cold start intermittent missfire |
Fri 06 Mar 2015 01:12:40 PM |
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hey guys so i made i little video hopefully its clear enough. i tried to keep the car at 80km for no paticular reason. first its in 4th gear then youll notice i change to fifth and then down to 3rd thinking maybe that will help with the different readings. this happens after 2min 40sec on the video. i hope this helps.
https://www.dropbox.com/s/m3mqilm8pgkh3hy/20150306_113631.mp4?dl=0 |
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frank2 » CMF Member birmingham United Kingdom Member since: Posts: |
Re: no cold start intermittent missfire |
Fri 06 Mar 2015 07:47:36 PM |
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it seems to be closed looping ok, but the k11,s have a speed sensor that holds it in closed loop in 3rd/4th/5th, it should do the same as this vid if the sensor wire is disconnected (or if you try in 1st and 2nd gear)
https://www.youtube.com/watch?v=N0sfY4dVcqM ie, it should bounce around .3 to .7v (closed looping) at cruise, then raise to .9v at wot, then 0v on lift |
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Lx_Micra » CMF Member sydney Australia Member since: Posts: |
Re: no cold start intermittent missfire |
Sat 07 Mar 2015 08:53:20 AM |
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mine dosent sit that consistent between every reading it goes down to zero. so it looks something like this.
0.650v 0.045v 0.570v 0.050v there not actual readings but that's what seems to be happening. |
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frank2 » CMF Member birmingham United Kingdom Member since: Posts: |
Re: no cold start intermittent missfire |
Sat 07 Mar 2015 11:36:12 AM |
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the readings will depend on what refresh rate the voltmeter has, so yours is closed looping ok from what i can see
does it hold at .9v at wot, and 0v on lift in 2nd gear tho ? |
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Lx_Micra » CMF Member sydney Australia Member since: Posts: |
Re: no cold start intermittent missfire |
Mon 09 Mar 2015 04:46:43 PM |
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It appears to work as you have described in second gear wot its .9v
and 0v when i take my foot off. So at low rpm its .9v as the rpm increases near its rpm limit it tapers of with the pedal all the way down. so it goes to 0.2v before i have to back of or change gear. Does that make sense? What else can i check on the car? |
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frank2 » CMF Member birmingham United Kingdom Member since: Posts: |
Re: no cold start intermittent missfire |
Mon 09 Mar 2015 05:42:21 PM |
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so thats ruled out a number of causes, does it start better from cold if you wet the air filter with a drop of fuel ?
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Lx_Micra » CMF Member sydney Australia Member since: Posts: |
Re: no cold start intermittent missfire |
Mon 09 Mar 2015 05:51:58 PM |
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ive never tried that but ill try do that in the next couple of days and get back to you.
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Lx_Micra » CMF Member sydney Australia Member since: Posts: |
Re: no cold start intermittent missfire |
Mon 23 Mar 2015 09:23:51 PM |
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i tried pouring a bit of petrol on the air filter maybe a cap full off a drink bottle didn't make a difference if anything it made it worse for little while.
is there anything else i can try? |
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frank2 » CMF Member birmingham United Kingdom Member since: Posts: |
Re: no cold start intermittent missfire |
Mon 23 Mar 2015 09:52:28 PM |
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valve timing out 1 tooth maybe ? post a pic of the lobes @ tdc like in the valve timing threads on here
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Mistikal » CMF Member Perth Australia Member since: Posts: |
Re: no cold start intermittent missfire |
Fri 27 Mar 2015 05:41:31 PM |
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Distributor cap.
Had the same issue on one of my K11s I wrecked, changed the entire dizzy and issue went away. Also a common fault on the 4E motors in the EP91 Starlet, issues with the points inside the dizzy cap arcing out or not arcing at all, and once the cap is warm, issue seems to go away. Pity you're not in Perth; I got a complete dizzy unit here you could use for testing. There are a few Sydney-siders on this FB group who don't frequent the forums much, they might be able to assist -- https://www.facebook.com/groups/238640209650320/ |
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