jcnash

Hi guys,

The temps are starting to drop to the single digits here in Canada and my car is starting to voice its opinion about the cold. Seems just like me, my car is a summer/beach person...LOL.

Anyway, the problem Im having is when I start the car in the morning (first start of the day after the car has been sitting for 8+ hours), it turns over, but sort of partially engages and makes the regular choking kind of sound over and over. This usually stops when I give it some gas, or like today, I just let it turn over again and again and it finally managed to engage and start by itself.

This only happens during the first start. Everything is restored to normal throughout the rest of the day.

Not sure what the problem is. Would it be fair to rule out the battery and transmission because this happens only when after the car has been idle for a while and when its cold outside?

What else could be the cause for this problem?

Any suggestions will go a long way in helping me fix this issue.

Thanks.

pcy

How old is the battery? If I were you I would have the battery tested and check the battery cables.

If not the battery, Fuel pressure may be going down during the night. If you leave the car alone for more than 4 hours during the day, does it start without any problems. You may want to test the fuel pressure before starting the car in the morning.

jcnash

Thanks pcy.

No idea how old the battery is. I got it with the car. Looks like the OEM battery though, so wouldnt be surprised if it was 8 years old!! Any way to check? Ive seen on here its possible to go into the Dyno mode to check battery voltage readings. But going into the dyno ode in my car gives me only 1 screen with info about the engine, oil level etc and another screen with the option to turn of the ESP. How do i test the battery?

I havent had to leave the car for more than 4 hours during the day, but I will try and give it a shot. How do I test fuel pressure?

samaritrey

get a new battery

jcnash

Doesn't seem like this is a battery problem though because the car starts fine on warm days and when its been started once. So if i start it, it hesitates, I give it gas/let it start by itself, switch off ignition and start again it works perfectly.

Still think it could be the battery?

Glyn M Ruck

Clean the MAF & make sure that the temperature sensor connections on the engine are good & properly earthed. You might not be getting sufficient mixture enrichment at startup. The ECU needs proper signals from the temp sensor to recognise that the engine is cold & fully enrich the mixture. In bad situations you might heve to replace the temp sensor.

jcnash

Thanks Glyn. I'm going to try these first before doing/changing anything drastic.

I'm also going to test it with a fresh batch of gas because the start of this problem seems to coincide with when i last filled up my tank to the brim with some gas at a random gas station because I was on a road trip and didn't have access to my beloved Shell V-Power dispensing station haha.

I'm almost at empty now, so I'm going to let it run out and fill up with some V-power goodness and test it out.

Glyn M Ruck

You might have got a tank of summer gas!

jcnash

Summer gas???

Glyn M Ruck

Yes - In the oil industry we tailor the distillation curve of gasoline dependent on the time of year & place. In winter we put more light ends into the fuel to improve cold weather starting & running & in summer we go to the heavier end of the distillation curve when those light ends are not required & could cause vapour lock etc.

Of course in a country like Singapore we don't do this because they don't have large differentials in ambient temperature across a year.

LILBENZ230

This is OT but the gas comments made me remember:

Glyn, the 135i just had its high pressure fuel pump replaced (common). And while I was there to pick it up the advisor asked me what kind of fuel I used. I said Shell V-Power and Chevron's Techron. He then said that Chevron fuel is no longer considered top tier. Is that true or is it typical dealership BS?

Glyn M Ruck

That's BS. It still passes muster to use "unsurpassed" in advertising. Techron concentrate is still the only thing that Benz approve.

Out of interest - BP's additive technology gives Techron the biggest run for it's money. The BP system is very close. Control of combustion chamber deposits is all that lets it down vs. Techron.

Things never stand still. Chevron has improved versions in the wings but it's not impossible that they will be deposed one day. It will be a good fight though. It costs a lot of money to put Techron into Chevron/Caltex/Texaco fuel & it has to be recovered in better sales.

Sorry about the 135i's HP pump. As you say common.

LILBENZ230

They replaced it before it ever really caused an issue, so proactive service FTW! Good to know about Techron - I'll be sure to confront the SA next time.

derecklouthood

Where is this temp sensor?!?!

Rev 2 Liv

And I am very curious to know, is this temp sensor different than the ambient air temp sensor that relays info to the LCD on the dashboard?

derecklouthood

Yeah i'm trying to figure the one that would send the ecu the right mixture as Glyn was speaking in one of his many threads

not the one on the front bumper for outside ambient temp...

The one aforementioned...

jtalbert

On the topic of gas, should we, if we can use Chevron/Texaco, and if we cant find that use BP gas whenever possible? I generally use Sunoco or LukOil. There use to be a few Chevron/Texaco stations around but they all disappeared, not a single one near me.

jtalbert

I answered my own question regarding LukOil. I filled up my car with this gas the last two fill ups, and at idle I started to hear a slight knock and I stared it up the other day and, it started but it was a little rough of a start. I put BP gas in my car today and the knock is gone and its running much smoother. I will not be using LukOil gas again.