itsawindupuk
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| posted on 20/1/15 at 01:03 PM |
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duratec cold start backfire
Hi everyone. I was wondering if anyone can help me with my cold map on my emerald ecu'd duratec. Basically whenever I try to start it I get
backfire out the throttle bodies and it burns my air filters. I'm guessing the spark is too advanced but I tried retarding it to no avail. When
warm it's great, sadly when it went to the rollers it was already warmed up.
Any ideas?
Thanks
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davidimurray
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| posted on 20/1/15 at 03:03 PM |
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How much advance have you got during cranking?
When does it backfire - while cranking, on starting, or after starting?
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Gallery 6 http://www.facebook.com/media/set/?set=a.10150550640070325.430417.601005324&type=3&l=fe779b358c
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flak monkey
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| posted on 20/1/15 at 05:01 PM |
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Typical cranking advance should be 8-10 degrees and 10-11 degrees at idle. Are you sure the programmed advance matches the actual advance?
Otherwise if the advance is ok, it sounds like its too lean. For a start try adding 10% more fuel on cold start and cranking enrichments and see what
happens.
Sera
http://www.motosera.com
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Kdempsie
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| posted on 20/1/15 at 07:21 PM |
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I had similar issues to this when I first started my Zetec engine, it needed more fuel to cure it. There is an interesting article on the Emerald site
(I think) that explains about the flame front speeds in the cylinders being reduced if the mixture is too weak. That means the cylinder is still
burning a little when the inlet is opened causing the pop back.
I'll post a link if I can find it.
http://www.emeraldm3d.com/articles/mar2012/
[Edited on 20/1/15 by Kdempsie]
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itsawindupuk
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| posted on 21/1/15 at 07:25 PM |
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Thanks for the replies guys. I'll plug my laptop in tomorrow and give it a try. Just got out of hospital so haven't had a chance yet but I
shall tomorrow and keep you posted.
Adam
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itsawindupuk
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| posted on 23/1/15 at 08:20 AM |
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Ok, I had a look last night and I must admit im very naïve when it comes to the mapping side of things (I left it to dave walker before). I took a
screen shot of the map, let me know what you think. Also, what happens is that when I start the engine, it fires up right away, then eventually dies
if I don't touch it. If I lightly touch the throttle it dies right away with a little puff out the inlet, and if I hit the throttle on and off
(only way to keep it going it seems) it will backfire and cough but eventually fire up and once its had a little rev it'll stay running and
everything would be fine.
 
Description
 
Description
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Oddified
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| posted on 23/1/15 at 08:56 AM |
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Sounds like there's enough fuel to start, but not quite enough fuel at cold idle once running.
Increase the cold idle fuel. I know mbe ecu's best and they have separate idle and running warm up compensation maps, if the Emerald only has
one, you'll have to do it on that. Increase the % fuel increase slightly in the area of temperature that there's a problem, eg looking at
your picture if the problem is around 10 deg, increase the 13% value. Keep the trend of values smooth so if you increase one area quite a bit,
increase either side value to keep the transition smooth.
Ian
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flak monkey
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| posted on 23/1/15 at 11:07 AM |
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Agreed with the above - needs more after start enrcihment, or whatever emerald call it. Add another 10% to those enrichments and see what happens.
You'll struggle to make it too rich to the point it wont run at all. If it's still bad, add another 10%. Once you get somewhere you are
happy you can start backing it off again. Cold engines (especially this time of year) need a lot of fuel on initial start up.
Sera
http://www.motosera.com
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