[Mike Bilton]

My 155 16V 2.0 starts perfectly every morning. However when the weather is hot (like today) and the car has been sat in the sun until the afternoon it sometimes refuses to start (the first attempt of the day). It will sometimes chug into life if you hold the accelerator down while turning over (as if the engine is flooded)

This has been an intermittant problem since I've had the car, about 5 years. I thought I could hear the cooling fan running so replaced the water temp sensor to no avail.

Any ideas?, I'm at a loss to see how such a small change in ambient temperature can effect how a cold engine starts.

As I say, it only happens if the car has been sat in the sun all day before I start the engine,

Thanks

 

[JackPJW]

I have had exactly the same problem with my 1.8 16v about 3 times in 7 years. Exact symptoms and I can also here what sounds like the cooling fan running when it refuses to start. Takes about 5 or 6 attempts and then finally chugs into life then is fine. never a problem when engine is hot just when startung from cold when it has been in direct sunlight, but again only very infrequent. I was talking to jimmybob about it only last week, he has never heard of it. I have no advice but it is reassuring to know I am not alone. If you find owt out let me know please

 

[Taka]

Same with all my previous Alfas. I reckon it's something to do with heat sink into the fuel. Maybe it vapourises in the line or something so you get a sort of vapour lock when you first turn it over.

 

[wrinx]

Had the same on the Twinny!!! Used to start after flooring the throttle while cranking, switching off and then doing it again.

wrinx

 

[Mike Bilton]

Good to know I'm not alone!

I wonder if it might be a faulty air temp sensor, tell the engine the air is cold when in fact it is hot.

The next time it happens, I'll get out with my multimeter

You would imagine this is a much more serious issue in Italy!

 

[Richard ARTC9]

I might have a solution for this problem, one of the ARTC members had the same problem.

One of our members (Alfa tec) told that there where production problems with some of the 16v eeproms of the main main ECU wich can give these problems.

Here in the Netherlands the dealers are told to replace these eeproms for free.

 

[marlon]

Maybe the heat under the bonnet is confusing a sensor and it thinks the engine is hot (as someone suggested). Maybe try cranking with just a little throttle when this happens.

Marlon

 

[Mike Bilton]

it happened again this afternoon

I noticed that the fuel injection light didn't go out as normal. - so the car 'knows' something is wrong.

Its reverted to normal now. Can anyone loan me a tester to read the memory, the Alfa garage wants £52 which is a real ripoff!

cheers

 

[Duetto]

Mine does this as well if parked in the sun all day. Injector warning light stays on and engine won't start. Suspect it's a problem with the ECU as if I leave the doors open for 10-15 mins to let the inside of the car cool down it will start. The idea of a faulty EEPROM seems likely. Wonder what the chances of getting this confirmed are and getting a dealer to replace it for free now. Wonder if it was common to other cars using the same ECU ??

Dave

 

[richward]

I've had this a couple of times too... I just thought it was vapourised fuel in the fuel line / injectors etc... but thinking about it, I reckon it's only happened from a cold start, so maybe the ECU gets confused with a cold engine and a hot (sun warmed) sensor?

 

[Mike Bilton]

I think it might be the air temp sensor. I disconnected and the light went out. Cooled it in some iced water(!) reconnected and still the light was out. Car then started normally.

Thinking about it this is the only part which could be a issue with air temp and not engine temp. Next time it happens I'll measure the resistance, anyone know what the values should be?

It might be worth investing in a new sendor anyway.

 

[tony24]

should be less than 1 ohm i think.
Thats what the leckies i work alongside keep preaching anyway

skinnyV6

 

[Pieter]

To solve this problem, you have to replace the main EPROM in de ECU.
When the problem is there, just unplug the airtempsensor, start the car, wait a moment and replace the airsensor plug.
There is a fault in the eprom, when it is messuring hot air temp and the engine is cold.


Pieter
member 119
artc member 121
155 1.8 16V S

 

[Mike Bilton]

pieter thanks for that advice, it does make sense. Did alfa admit there was a fault?

The resistance shouln't be 1ohm, more in the region 100 to 2k ohms.

 

[Duetto]

Interesting, I'll have to try that. Is the air temp sensor the one in the top of the air hose just before the throttle body ??

I'm pretty convinced I can avoid the problem by leaving the passenger window open a fraction to stop the heat inside the car building up too much. Perhaps I've just been lucky.

Dave.

 

[Mike Bilton]

Yup, that's the sensor, let us now how you get on

 

[Duetto]

Have confirmed Pieter's Solution works.

Left the car in the sun today with the windows closed till it was really cooking inside. On turning the ignition on the injector warning light stays on and the engine won't start.

Popped open the bonnet and disconnected the air temp. sensor wire. Turning the ignition on again this time the injector light goes out as it should and the engine starts no problem !

Very useful to know the solution to this little glitch as it's a bit of a pain when it happens.

Be interesting to know if the local dealer knows about this (Sidlow at Gatwick)and whether they will do anything for free - doubt it somehow. I'll probably ring them in a day or two.

 

[Pieter]

I am glad that my solution is working. After i found out, i informed my local dealer and they asked by the importer. They knew the problem, there is a range of eprom's with this problem.
I replaced it (must pay half of the price).
But i have since two weeks the eprom replaced for a Squadra chip (www.squadra-tuning.com). On the whole range of rpm more power and more torque, especialy by 2000 rpm. Better, more direct reaction on the gas pedal.

Pieter
member register 119
artc member 121
155 1.8 TS 16V S

 

[Chris155]

Errr mine's doing the same thing (2.0 16V) and I've got a squadra chip in it.

Going back to the fuel vapourisation thing, the noise like a fan could be the fuel pump. If you're leaving the ignition on while you disconnect the air temp sensor it could give the pump enough time to build up fuel presure in the injection rail (perhaps). Or maybe the engine managemet doesn't like an ambient air temp of over 50 deg that you'll find after leaving the car in the sun. You probably let the car cool down inside (door or window open) while disconnecting the air temp sender.

Its just a thought. Its a little inconsistent that mine does the same thing with a SQUADRA chip in it.

 

[Duetto]

Strange problem. I'm certain Pieter's suggestion is the solution. When I tried it on Sunday I kept the doors closed and the ignition off whilst unplugging the sensor wire which probably only took 10 seconds. The car started straight away afterwards with no injector warning light. Having suffered this problem on occasions for a couple of years it seems normally to take 5 or 10 mins for the inside of the car (the ECU I presume) to cool down enough for the car to start. I've not actually looked inside the ECU as I still have the standard chip in it but I suppose it's possible that it's another chip in the ECU that needs to be replaced to cure the fault. I think at the moment I'm going to be happy just disconnecting the sensor when it's too hot rather than have my nearest dealer start changing things as I suspect they won't have any knowledge of this problem. I think I will ring them just to see what they know or are able to find out though.

Dave.