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Help !!!!! engine start problem

8K views 7 replies 2 participants last post by  andy1805 
#1 ·
hi guys

Hopefully someone here can help me, I have a 2000 156 2.5 v6
and when the engine is hot it wont start it turns over no problem but wont fire up almost as if the engine is flooded.
I asked my nearest alfa dealer who said it could be anything and id have to book it in. I was hoping someone here might be able to narrow the search for me ?????
 
#2 ·
This sounds very much like a problem that I had. The solution was to replace the crank sensor position located on the flywheel. My car would not start on hot summer days soon after shutdown. The car would always run perfectly. So, I suspect that modern Motronic systems utilize this sensor more for starting than running.

Alternately, when a cold starting condition exists, the temperature sensor is usually at fault. However, this seems to be much more rare to have a faulty temperature sensor.

Best regards,
Ken
 
#3 ·
thanks

Hi ken
Thanks very much ill have that checked..
It only does it if while running the car it gets up to 90 on the temperature gauge, and it will start up again within 5 minutes or so but if left say 30 minutes it wont. Very odd. Like the engine is flooded or something.
 
#4 ·
The part itself is difficult to diagnose, you will need an oscilloscope. Replacement takes only about half an hour. So, it is cheaper to replace the item rather than run through complete diagnostics. From what I can tell, the price on this part is less than € 50.

Your no-start description is a perfect example of the crank position sensor failure. The part number is 46472687. Just replace the sensor, you will be pleased. I first heard about this from someone on a forum, it certainly solved my problem. This is one of those items not in the service manual.

Best regards,
Ken
 
#5 ·
garage said

Hi Kens / anybody interested

I took it to a garage today and told them what you had said he seemed ok with it but he said if it were that i would have an engine management light on but he said he would check it out. 3 hours later i picked up the car and he said it was the RPM sensor. Unfortunately i have no idea what this is or if this could be causing my problem. But hes fitting a new one on wednesday for about 100 pounds. Hopefully it will be the cure. Any input / opinions welcomed
 
#6 ·
It sure sounds like we are talking about the same sensor. Crank angle sensor and RPM sensor are the same the parts CD just calls it a sending unit. From 2001 forward, all cars have EOBD which I am sure would record an error on this unit in particular. My 2000 166 never threw an error. Likely thinking about the newer cars, the service fellow probably expects codes these days.

Anyway, after you hit a few hot days. Let me know how it turns out. I am optimistic.
 
#8 ·
Fixed at last

Hi Kens

Just to let you know i had the RPM sensor changed and it has fixed the problem which is great. To anyone else with a similar problem getting a new RPM sensor at a cost of 123 pounds fitted worked for me.

thanks for your help kens much appreciated.

regards
Andy
 
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