mcerd1
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| posted on 30/5/17 at 12:46 PM |
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1.8 duratec - very rough idle when cold
My tin-top has developed a bit of an issue when starting from cold and recently I've had one or two issues with it stalling at low revs too
first thing this morning it was very reluctant to start and when it did the idle was really struggling, bouncing from ~500 to 750rpm and back and just
didn't want to rev at all 
with a fair bit of right foot it eventually rev'd up then settled back at its normal ~1100rpm idle it does when warming up
OBD doesn't show any codes (stored or pending) and most of the figures in the live data look fairly normal too - except the IAT that starts off
at just a few °C above ambient, but once the car is warm reads 35 to 39°C (with ambient at ~20°C) - that doesn't sound right to me, but I guess
it could come from the EGR setup ? never had a car with it before to compare it....
so far I've not found any vacuum leaks either which is what my instincts are telling me to look for
anyone got any other thoughts ?
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adithorp
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| posted on 30/5/17 at 02:00 PM |
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First thing I'dtryis clean out the throttle body.
"A witty saying proves nothing" Voltaire
http://jpsc.org.uk/forum/
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r1_pete
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| posted on 30/5/17 at 04:40 PM |
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Sticking fast idle valve maybe??
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britishtrident
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| posted on 30/5/17 at 04:43 PM |
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The inlet air temperature is normal. The engine is smoothing out when it goes closed loop so I would look at the OBD data for short and long term
fuel trims STF1 and LTF1 if when warmed up and running closed loop at normal idle the total fuel trim adds (ie. STF1+ LTF1) up to much over 10
percent the engine is adding fuel to try and counter a lean condition. If raise the RPM to 2500 and hold it there for 2 minutes and the total fuel
trim falls back to closer to 0 percent say 5 or 6 percent then it points to a vacuum leak.a
If the total of the fuel trims stay over 10 percent or increase then suspect a dirty MAF or fuel pressure issue.
Cleaning the MAF and Inlet Air Control Valve is always a good idea on Fords as is cleaning and checking the EGR.
However Fords are very prone to vacuum leaks and I would do a water spray test on the manifold and pipes.
[Edited on 30/5/17 by britishtrident]
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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mcerd1
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| posted on 31/5/17 at 04:06 PM |
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quote:
Originally posted by britishtrident
The engine is smoothing out when it goes closed loop so I would look at the OBD data for short and long term fuel trims STF1 and LTF1 if when
warmed up and running closed loop at normal idle the total fuel trim adds (ie. STF1+ LTF1) up to much over 10 percent the engine is adding fuel to try
and counter a lean condition. If raise the RPM to 2500 and hold it there for 2 minutes and the total fuel trim falls back to closer to 0 percent say 5
or 6 percent then it points to a vacuum leak.
If the total of the fuel trims stay over 10 percent or increase then suspect a dirty MAF or fuel pressure issue.
I'm not getting any more than ~10% on the long term with a steady throttle, and that backs off almost instantly at idle
quote:
Originally posted by britishtrident
Cleaning the MAF and Inlet Air Control Valve is always a good idea on Fords as is cleaning and checking the EGR.
However Fords are very prone to vacuum leaks and I would do a water spray test on the manifold and pipes.
I've dealt with the vac leaks on my old 1.8 zetec tin-top before - at least most of the bits on this engine are on the front instead of squashed
between the bulkhead and the engine.... mind you at least the zetec didn't have EGR
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