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Discussion Starter #1
What RPM does your 4C cold start/fast idle at before dropping to idle? Mine seemed to be run faster/louder than it has been doing recently but I can't remember exactly what RPM it was before. Now it cold starts at about 1100rpm before dropping to about 800rpm idle. I'm pretty sure it cold started at 1300-1500rpm then dropped to 800rpm before. I don't know why... the weather has gotten colder so I would've expected the opposite.
 

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What RPM does your 4C cold start/fast idle at before dropping to idle? Mine seemed to be run faster/louder than it has been doing recently but I can't remember exactly what RPM it was before. Now it cold starts at about 1100rpm before dropping to about 800rpm idle. I'm pretty sure it cold started at 1300-1500rpm then dropped to 800rpm before. I don't know why... the weather has gotten colder so I would've expected the opposite.
About 1100rpm, though our temps here at the moment are a little warmer than yours.
 

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Discussion Starter #3
I just removed my battery, did a charge and recondition on a CTEK charger and put the battery back in the car and it cold started just like it used to, so perhaps my battery has a problem. I disconnected the battery so it would've also reset the ECU so this could also be the reason... hmm
 

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I just removed my battery, did a charge and recondition on a CTEK charger and put the battery back in the car and it cold started just like it used to, so perhaps my battery has a problem. I disconnected the battery so it would've also reset the ECU so this could also be the reason... hmm
History has shown most electrical gremlins are battery condition related.
 

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Discussion Starter #5
About 1100rpm, though our temps here at the moment are a little warmer than yours.
I was wrong about the RPM, when it cold started just now it was about 1100-1200, so only slightly higher than it has been recently, but it's a very noticeable difference in the loudness of the fast idle
 

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Discussion Starter #6
History has shown most electrical gremlins are battery condition related.
It's only a year old and hasn't ever been fully discharged (though at times it might get left for 7-10 days without running but will start up fine) so is it normal to have issues with one in such a short life time?
 

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It's only a year old and hasn't ever been fully discharged (though at times it might get left for 7-10 days without running but will start up fine) so is it normal to have issues with one in such a short life time?
My battery is at least 4yrs old without any problems so far, so I’d say not normal in your case. My 4C gets used, on average, once every two weeks but that once is generally a drive of around 200km. I did have a problem with my old Giulietta Multiairs’ battery failing to start the car and it was a little more than 1year old at the time. Apparently it had dropped a cell and what charge remained wasn’t enough to crank it. That battery was replaced under warranty.
 

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Discussion Starter #8
I started it up 24 hours later and it was doing the reduced fast idle thing again so I'm back to square one. Any ideas?
 

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Mine cold idle is always 1,100 to 1,200 rpm before it settles down no matter the weather. but then again, here in Florida a cold morning might be 40 to 45 degrees
 

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Discussion Starter #10
My cold idle is barely above 1000, maybe 1050 at most. Definitely not up at the usual 1100-1200. It always cold started there before but the only time it's done it in the last 2 months was when I removed and charged the battery. Still don't know I need to the find a way of determining what's actually causing it. I think I will try to connect the trickle charger up whilst the battery is in the car so that I can determine whether it was the ECU reset or the battery charge/voltage that cause the cold idle to go back up to 1100-1200. I don't want to spend on/order a new battery to find out it wasn't the cause...
 

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Discussion Starter #12
Here's the weirdest thing..

When I start the engine cold and it doesn't go into fast idle mode and I turn the engine off quickly before it heats up, if I immediately start the engine a second time, it roars back and goes straight to fast idle cold start.

I would really like to fix this because getting that cold start sound at the beginning of my drive is part of the drama of getting in the car for me.
 

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I really have no idea, except to suggest you take her out for good long hard open road drive (thrash), not a suburban idle-around, and that might just clear the issue...a contaminant on a sensor. At least it starts and idles. Couldn’t do any harm.
 

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Discussion Starter #14
It's been doing this for a couple of months now, in which time I've done many hard drives, so I'm giving up hope that'll just fix it by itself.

You're right, could be worse, and at least the car works and I can drive it. It's just something missing from the experience I've gotten used to enjoying.
 

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O
It's been doing this for a couple of months now, in which time I've done many hard drives, so I'm giving up hope that'll just fix it by itself.

You're right, could be worse, and at least the car works and I can drive it. It's just something missing from the experience I've gotten used to enjoying.
oh well, it was only a suggestion. Chances are it is some sensor but that’s only a guess. If it’s really upsetting you need diagnostics. Any code reader handy?
 

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Discussion Starter #16
Yeah, appreciate it man. Unfortunately don't have access to a code reader. It was only serviced recently so won't be back a garage for a while unless I take it especially for this to be looked at. Out of warranty so would need to pay for anything.
 

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Hi Lawrence,

I did read on here that when the power is taken off the ecu, it loses the set point for the idle air control on the throttle body and there is a way to reset it that has something to do with the way you power it up with the key.

If my memory serves me correctly, you have to disconnect the battery. Wait 30 seconds or so, reconnect the battery, turn the ignition to the on position, but do not start the engine, wait 10-15 seconds, turn it off, repeat two or three times (can't recall exact number, but it's more than once) and finally you can start the engine.

The ecu will step the idle control through its full range while you do this little set up game. It then learns where the extremes are and the midpoint and loads of others in between. It will then pick a default position for first start and adjust from there, then remember the set point of the idle for future use and adjust it accordingly.

I think Chris at Eurocompulsion has a how to guide on his website - under fitting the ecu.

Hope that helps Mate - keep the old battery on a condition charger and it will always be available for jump starting your snow plow as its winter there isn't it?

Cheers,

Alf.
 

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Discussion Starter #19
Thanks for the response Alf.

I'll try to find the eurocompulsion guide but what you describe is actually exactly what I've been doing each I've removed or disconnected the battery. The problem is that 24 hours later, it is back doing what it was doing before. I'd assume it was normal but prior to a couple of months ago, the car would always start with a fast idle at about 1100-1200 rpm.

The most confusing thing is that if I start it, let it idle at about 1000 for a just a few seconds, then turn off, then start it again, it then properly idles at 1100-1200rpm before settling down to 800. This is why I thought it might be the battery because I thought the few seconds of the alternator running was pushing the voltage up to a level the car needed that maybe it wasn't getting from the battery, so when cranking it a second time it could do it's cold start properly, but now that I've tried a brand new battery (measured at 12.87v with multimeter) that can't be it.

Maybe I'll be able to get a video of this tonight and upload

Hi Lawrence,

I did read on here that when the power is taken off the ecu, it loses the set point for the idle air control on the throttle body and there is a way to reset it that has something to do with the way you power it up with the key.

If my memory serves me correctly, you have to disconnect the battery. Wait 30 seconds or so, reconnect the battery, turn the ignition to the on position, but do not start the engine, wait 10-15 seconds, turn it off, repeat two or three times (can't recall exact number, but it's more than once) and finally you can start the engine.

The ecu will step the idle control through its full range while you do this little set up game. It then learns where the extremes are and the midpoint and loads of others in between. It will then pick a default position for first start and adjust from there, then remember the set point of the idle for future use and adjust it accordingly.

I think Chris at Eurocompulsion has a how to guide on his website - under fitting the ecu.

Hope that helps Mate - keep the old battery on a condition charger and it will always be available for jump starting your snow plow as its winter there isn't it?

Cheers,

Alf.
 

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Lawrence,
I would take the engine cover off and check your harness connectors and any vacuum tubing you can find next to eliminate the obvious things that can give dodgy information to the ecu.
Cheers,
Alf.
 
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