Non Starter below 5

[MAC 1]

Hi guys, my first posting on your site and I'm needing help please.

I have a '94 GPX MIVEC tipo that mysteriously refuses to start when the ambient temperature is below 5 degrees C.
If it is any warmer than this it will start easily. Doesn't matter how long it's left either, it is purely a temperature related problem.
I have had it in a garage for over 5 weeks now and we still can't find the cause. Several parts have been renewed and there are no error codes showing on a MUT11 diagnosis gizmo.

Does anyone have any ideas what could be causing this?

Thanks, Mac.

[ronbyrne]

next time temp is below 5c, heat the external temp sensor with a hairdryer or similar, if it starts then you know its somewhwere along those lines, if it doesnt, then its not ecu or electronicaly related and must be injector (coldstart injector ) or something else, process of ilimination , you better find it fast though as its nearly irish summer time and the temp has on ocasion creeped above 5c

[MAC 1]

So does the external temp. sensor have a relationship to the engine management system then? I didn't think they were connected.
I have replaced the engine temp. sensor. The ECU has been tested along with all other items that the MUT11 diagnosis covers. No fault codes whatsoever showing up. Fuel system and pressure test also checked out clear.
Your comment about the weather is a valid one. I mentioned to the mechanic only today that spring is approaching as it was a balmy 7 degrees at mid-day today.

[steelroe]

Wonder would it have anything to do with the idle control motor. Might be stuck fully closed.


What was the name of the Garage you brought it to that has the MUT-II

do a search for
"car won't start when cold" and you will find a couple of possible causes. Moisture in the petrol tank seem's to be a common one.

[MAC 1]

Hi Steelroe,
Idle control valve (Stepper motor) was the first thing I replaced as it is often the culprit for this type of problem. However, the garage have tested it and also they tried substituting it for another one, it is working fine. So it is not that.
The garage is AP Motors in Plymouth, Devon, England. They have a really good reputation with the imported performance car fraternity, so I'm confident they are doing the best they can.
I've tried surfing the net and to be honest there are so many possible causes it is a process of elimination really. Blo0ddy frustrating and becoming very expensive to boot.
Not sampled the petrol but it may be worth doing. Would water not cause a general running problem though as this only occurs when its cold otherwise it is fine.
Cheers, Mac.

[MAC 1]

Just remembered another thing, the fuel pressure has been tested and is good.

[pergau]

Seriously,

The hairdrier trick sounds like a good step to take. It is possible that one of the components has a hairline crack due to shrinkage in the metal (hell, we all know about shrinkage in clod weather) and that this closes when the metal warms and expands a bit.

Years ago I worked on a computer system that had unexplained errors every morning but would setle down around 10 or 11 am. We eventually traced it to a fractured hard disk. In your case, it could be cracked solder.

[MAC 1]

next time temp is below 5c, heat the external temp sensor with a hairdryer or similar, if it starts then you know its somewhwere along those lines, if it doesnt, then its not ecu or electronicaly related and must be injector (coldstart injector ) or something else, process of ilimination , you better find it fast though as its nearly irish summer time and the temp has on ocasion creeped above 5c

Are you referring to the air temp. sensor on the inlet manifold? or to the air temp sensor that tells you what the external temp is (displaying on the A.C. panel)?

If the former then I have already suggested (yesterday) to the garage that they may want to check this is functioning correctly.

[mcgon1979]

(man these posts are so old)

did you ever sort this... have my car 2 or 3 weeks. but twice when it was cold it didn't start on the button.
It cranked maybe 5 times and I let go of the key. Got it on the second go though after a couple of cranks. idles perfect, drives perfect. and when its warm it starts immediately.
maybe I just let go of the key too quickly. less than a second like.

probably nothing. Its always a sensitive few weeks getting to know your new car. maybe I should stop reading the technical forums for recreational reading.

One thing I did notice though (which is not really a 'problem') is that the mivecs like oil. a lot. checked the oil when I got it 2 weeks ago and it was just on max on the dipstick. I've done about 900km and its now on halfway or just below. top up time I think.

[CJ]

One thing I did notice though (which is not really a 'problem') is that the mivecs like oil. a lot. checked the oil when I got it 2 weeks ago and it was just on max on the dipstick. I've done about 900km and its now on halfway or just below

MIVECs like oil but not that much! Using a litre or two oil oil every 1k kms in not normal (I change the oil every 7k kms or so and never have to top up). You sure the car was level when you checked it first time around? Top it up and check again in a few weeks - if you see the same level of consumption then get it checked out.

CJ

[mcgon1979]

actually... you know what CJ I was on a slight slope when I checked it first time around. Never even though of this!! Was backed into a driveway with about a 5 degree slope. Was deffo level when I checked it second time.
I'll top it up and keep an eye on it.

I'll be happy once I do the full service + belts sometime next couple of weeks. I'll know where I stand with the car then. I've just been building up all the parts so I can do it all at once. plugs/filters/belts etc.

[kevinod]

did you ever sort this... have my car 2 or 3 weeks. but twice when it was cold it didn't start on the button.
It cranked maybe 5 times and I let go of the key. Got it on the second go though after a couple of cranks. idles perfect, drives perfect. and when its warm it starts immediately.
maybe I just let go of the key too quickly. less than a second like.

Any idea when your spark plugs were done last? I've heard that a car not starting too quickly from cold can be due to worn spark plugs.

[mcgon1979]

Hey Kevin,

I suspect this could be it myself. No idea when the plugs were done. Certainly not in ireland. The car is only over here a few months. It has 90000km on the clock so the plugs have probably only been changed once I'd say.

I have a shiny new set of 6 IK22 Denso Iridiums which I cannot wait to put in!

Thanks for the suggestion, I hope that could be it. I'll let you all know after she gets the full service.

ta