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Discussion Starter #1
When I first start from cold I've lost enrichenment. It stumbles and stutters until warm and I have to rev it and slip clutch, fine when it's over about 3000 revs, but bad below. I can't remember what controls cold enrichment, is it one of the 2 senders on the front right side of the engine located in the water system? Anyone know the resistance to check if it has blown?
 

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London Mike said:
When I first start from cold I've lost enrichenment. It stumbles and stutters until warm and I have to rev it and slip clutch, fine when it's over about 3000 revs, but bad below. I can't remember what controls cold enrichment, is it one of the 2 senders on the front right side of the engine located in the water system? Anyone know the resistance to check if it has blown?
I'm not sure about the M motors, but my 4.0litre V8 is having the same issue. It has been diagnosed as a faulty PCvalve - leads to very rough idle when cold - seems to disappear when warm and not a problem under throttle.

So, if it doesn't appear to be the result of the cold start engine management system, might be worth a look!

Cheers
 

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Mike (and anyone else on the board)

Although possibly not the reason for your problem, I've got a spare, tested and working, Idle control Valve from my car.

I live in Hertfordshire, so could get it to you somehow if you need to swap one out.

I bought a new one believing this one to be faulty. It wasn't, and they're not an especially cheap component.
 

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Discussion Starter #4
Thanks Andy, that's great. I'm not sure what this is, it feels like a too-lean mixture at start-up and I just assumed that there was an electrical sender in the waterway somewhere. What symptoms did you have that caused you to change it?
 

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Very poor cold idle and starting. My coolant temperature sensor (the one near the thermostat) was fine, as was the TPS. I've still got the problem, and my specialist has suggested the throttle bodies need balancing, which is possibly true - they are very sensitive to adjustment. I have been working away and the BMW dealer here (Westerly, Exeter) refused to balance them.

The other things which could affect are:

Vacuum Leaks - spray carb cleaner around the intake tubing and MF to see if the idle rises = leak
AFM - you can unplug that to simulate a failure
CTS - You can measure the resistance, but I haven't got my Haynes Fuel Injection Manual to hand to tell you the values
TPS - You can measure the resistance
FPR - You can measure the fuel pressure with a meter.
ICV - Hard to test without a replacement
Body Balance - Impossible to test without resetting, specialist eqpt reqd

I don't think I've missed anything.
 

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Your symptoms are slightly different to mine though - I have to use a touch of throttle to start the car, and then it idles poorly at around 500rpm or slightly less. Once warm, it's absolutely fine, and idles at 750. This fault is not intermittent.
 

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Discussion Starter #7 (Edited)
Andy, I do need to eliminate this for sure. If I cover the postage, would it be possible for you to send it down to me so I could test it? Car's booked in on Friday for suspension work and I was going to ask them to look at cold start too. Any chance of getting it in the post today so I get it tomorrow and can try and confirm or eliminate it before it goes into the garage? I'd drive to you and try it, but as the car needs to be cold.... :rolleyes:

If you can't that's absolutely fine, just an idea that might speed things up... :)

ps What number is your LE, mine was 46 ( :crying: )
 

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Unfortunately I'm not at home again until Friday night, which is where the ICV is at the moment. I'm at Bruntingthorpe on Saturday and largely free on Sunday.

My LE is #14.

Whereabouts are you in London? I could post it on Friday night if you'd like. Drop me a PM or email to [email protected] to let me know.

Cheers,
Andy
 
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