mongrelwestie
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| posted on 31/7/08 at 08:47 AM |
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ZETEC TICK OVER???
my car is running a 2.0 zetec from a 1993 mondeo, on a griifen power injection system.
when i start it, hot or cold it struggles to tick over, keeps dying.
as soon as i give it a run it is fine!
any ideas on what it could be?
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coozer
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| posted on 31/7/08 at 08:49 AM |
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Cold start enrichment perchance?
Mine is a basic (cheap) bike carb, megajolt setup that will start from cold and idle at 500rpm and goes up to 950 when warm.
1972 V8 Jago
1980 Z750
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Paul TigerB6
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| posted on 31/7/08 at 10:05 AM |
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As Coozer says its likely to be the cold start enrichment.
The Griffin system uses and idle control valve (cold idle valve) doesnt it?? Worth taking this out and giving it a good clean for starters to see if
it improves matters.
Another possibility is the water temperature sensor has packed up / dirty contacts
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mongrelwestie
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| posted on 31/7/08 at 10:31 AM |
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ok ill give that a go
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Dusty
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| posted on 31/7/08 at 01:55 PM |
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Look on the basic idle screen in map3000. You can set hot idle revs and make a correction for faster idle at below a specified temperature.
Mine reads top to bottom.
1.95%. 1400rpm. 950rpm. 60C. +150rpm. 0.52S. 0.26S.
So engine enters idle program if throttle less than 2% open and revs below 1400. It tries to maintain 950 rpm using spark advance or idle air bypass
except when engine temp is below 60C when it adds 150 to give cold idle target of 950+150 =1100.
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Dusty
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| posted on 31/7/08 at 02:05 PM |
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I have no experience of the air bypass and use idle scatter spark table to maintain idle. Graph is found under idle heading, spark scatter and shows
ignition correction to be applied to the timing dependant on how far above or below the target idle the revs are. Graph is pretty much a straight line
from +20deg at -325rpm to -10deg at +300rpm but taken through the zero deg/zero rev point.
If revs drop to 750 and target revs are set at 950 hot the ecu notes it is in the idle mode and 200 below target, looks up the correction in the table
and adds 12 degrees of extra advance to ignition which has the effect of raising engine speed. As engine speed increases the correction is reduced and
is zero when engine gets back to 950rpm target. Sampling rate and decay time can be adjusted to avoid over-correction or hunting. Works a treat. Does
need to have the throttle stop cracked open so some air is going into the engine for it to play with.
[Edited on 31/7/08 by Dusty]
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