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Hard Start When Cold

Jerome81

Autocross Newbie
Location
USA
I've searched, I've participated in other threads, but I still can't seem to find much info on what is causing this hard or difficult starting problem when the car is cold.

Now that winter has hit and it is in the 20's outside, after the car sits for many many hours, I crank, and the car has sorta sputtered and died on the first start. Or I crank and it kinda stumbles to life. It has me bothered, but it seems nobody here has ever figured out if this is battery, plugs, coil packs, fuel pumps, etc.

Car runs fine otherwise. Perfect.

2008. Completely stock.

I'm thinking about taking it to the dealer, but I will need to get a ride from a friend, leave it overnight, etc. Its a pain.

If there are any new developments on what solved this issue, please post. May help when getting to the dealership.
 

likes2driveslow

Ready to race!
Location
California
yeah i have this problem. it doesn't throw out a code so my stupid dealer can't figure it out.

someone on here suggested it's the low pressure (in tank) fuel pump. after reviewing some literature, that pump seems to change it's operating pressure depending on ambient temperature. this pump also doesn't throw a code.

next time i go to the dealer, i'm going to bug them about looking into that.
 

vagike

Newbie
Location
Edmonton
my does the same. Well, it has not stalled out on a cold start. I can definitely tell my battery is a touch weak when cold.

I would put a trickle charge (standard battery charger) on it overnight, and see how she starts.

if you do alot of short trip driving (less than 20min of driving) you are slowly killing your battery too. Especially in the winter, since you are running more electrical accessories (heated seats, rear defog, etc) you more power than usual from the charging circuit, and your car requires a long drive-time for it to charge itself back up.
 

BoardSnow6

Banned
Location
WPA
Car(s)
Capita Scaremaster
I believe that this problem is covered in a common problem thread... Id give you the link if i could find it...
 

Ronan1

Ready to race!
Location
San Francisco
Mine's a 2008 with 76k miles, and well maintained. I have had the same issue for months. In the morning, usually doesn't start first time, or takes a longer crank and then finally an uncomfortable start.

No codes. Changed the plugs, no difference. I haven't changed the coil packs, but I read on an earlier thread that someone with the same issue said changing their CP's made no difference.

I have not tried the fuel pump sensor.

Anyone else done this with success to this issue?
 

Jerome81

Autocross Newbie
Location
USA
Yeah, this issue still sounds like it isn't resolved. Bummer. Had hoped maybe I'd hear some sort of revelation.

I need to go to the dealer to replace the head unit ( CDC Hardware Error ) so I will talk to them. Not gonna leave the car overnight. last 2 days it started fine first try. Inevitably if I leave it at the dealer one night, the next day will be one of those days when it starts just fine....

And I'm pretty sure I have the fuel line rattle....which of course every time I get to the dealership is never occurring either.

I will ask what might cause it and the fuel pump sensor.
 
Location
So Cal
Quick and possibly stupid question, do you put the key in the crank immediately? Or do you put the key in, wait for the fuel pump to prime, then crank the motor?

I found that if I do the former, it'll sputter and sometimes die out. But if I wait a few seconds, she starts no problemo
 

Wild Hare

.: MR. BIG STUFF :.
Location
Nortvest
Car(s)
2015 Golf R (TUNED)
I have the same problem as well. It's at the dealer right now for the Mechtronics replacement and to check on this cold start issue.

They've had it two days just to see if the cold start acts up. Nada so far.
 

nashbar

Ready to race!
Location
lake minnetonka, mn
Car(s)
b5s4, fz1 and mk5
the problem is a leaky check valve between the hpfp and the lpfp. it doesn't maintain enough pressure over several hours of being parked. it's fine as is, the lpfp runs when you open the door for a reason. just takes a few extra revolutions to get good pressure at the injectors.
 

Ronan1

Ready to race!
Location
San Francisco
Quick and possibly stupid question, do you put the key in the crank immediately? Or do you put the key in, wait for the fuel pump to prime, then crank the motor?

I found that if I do the former, it'll sputter and sometimes die out. But if I wait a few seconds, she starts no problemo

I have tried this and it really makes no difference in my case.
 

Ronan1

Ready to race!
Location
San Francisco
the problem is a leaky check valve between the hpfp and the lpfp. it doesn't maintain enough pressure over several hours of being parked. it's fine as is, the lpfp runs when you open the door for a reason. just takes a few extra revolutions to get good pressure at the injectors.


Interesting. Is this based on you actually having the same issue and fixing it?

Where is this check valve located? Up till now, I guessed it might be a function of dirty valves since my car has 76k on it.
 
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