Cold plugs, cold weather cold start idle implications

[s1ngletracker]

Random thing I've been thinking about... would running colder plugs make my car idle poorly on cold starts in MN Winter weather? My cold idle is starting to get rough and the car wants to die more and more as the weather gets colder.

[s1ngletracker]

Ok, so today was pretty awful. Still looking for help on this. Pulled the plugs, they seem fine, I'm assuming they aren't the cause.

-Compression tested, came out normal
-Swapped out MAS for a known good one, no change
-New coolant temp sensor
-Swapped out hte ISC, which tested good, but there still might be a slim chance it is bad
-I have previously deleted the wax plug fast idle thing. I realize this impacts cold idle, however, it was deleted last winter and didn't have this problem

Things I'm going to test/change out:
-Plug wires
-Coil
-Ignitor
-Look at fuel pressure while cranking and ensure all is good there.

Could these be the cause? Are there any other ideas as to why my car just WILL NOT idle on cold starts? I have to hold down the gas for about a half minute before the car will idle on its own without dying.

Also, side question, to properly set the idle, I just need to ground out the one pin on the test connector at the firewall, then adjust the base idle screw, right? Or is there something else involved? The manual is a bit confusing on this, it talks about grounding something else out, a pin on the diagnostic connector that my connector doesn't even have.

Any help is appreciated. I realize there are few knowledgeable people here that even drive dsm's anymore, and even fewer that daily drive them in the winter, but worth a shot.

[Matt D.]

Also, side question, to properly set the idle, I just need to ground out the one pin on the test connector at the firewall, then adjust the base idle screw, right? Or is there something else involved? The manual is a bit confusing on this, it talks about grounding something else out, a pin on the diagnostic connector that my connector doesn't even have.
I'm pretty sure that is to set the base timing.

I know our cars aren't much alike but my car is a bitch to start in the cold. When it's below freezing I just have to hope it fires and I do have to keep on the gas for a bit until it idles on its own. This was even before I had bigger injectors and cams and it's no different after.

[TheBlizzard]

If you car is harder to start when it gets below 30 degrees it is likely one or both of your coolant temp sensors are bad. If they are bad the ECU thinks the air temp is hot so it does not enrich the fuel enough to start it. I would check there first, if not your ECU could have issues as well.

[s1ngletracker]

If you car is harder to start when it gets below 30 degrees it is likely one or both of your coolant temp sensors are bad. If they are bad the ECU thinks the air temp is hot so it does not enrich the fuel enough to start it. I would check there first, if not your ECU could have issues as well.

As I said in my post, I replaced one of the sensors (even tested the new one, checked out ok), the one for the ECU. There are 2 more, right? 1 for the A/C and one for the... fan switch? Either way I dont think either of those would have a huge impact on starting. I definitely smell gas if it takes me a few tries to start it without much success... I almost think its probably running TOO rich. Don't have a whole lot of evidence to back this up though. What would cause it to run too rich?

I'm not getting any check engine lights.

I wouldn't be thinking much of this, if it weren't for the fact that it didn't have this problem last year, not even in -10 degree weather, it would at least idle on its own.

I've had the ECU out and examined it closely, no leaking capacitors. Maybe I should have them replaced anyway?

I think i'm gonna log it when it first starts and post it up here for input.

[s1ngletracker]

ok, well, this is on hold for just a bit, due to my water pump catastrophically failing last night, the bearing failing and the pulley breaking off and bouncing around my engine bay, spewing out all my coolant and making a huge smokey mess :( My car IS a DSM! go figger.

[mnnice]

If you car is harder to start when it gets below 30 degrees it is likely one or both of your coolant temp sensors are bad. If they are bad the ECU thinks the air temp is hot so it does not enrich the fuel enough to start it. I would check there first, if not your ECU could have issues as well.

this wouldnt throw a cel would it? my car has the same issues. it doesnt idle until it warms up

[niterydr]

Is the car tuned? Many "tunes" will not address cold start as vehicles are very tempermential in cold weather conditions.

Another issue is that when it is cold air leaks are even more vital. My truck for example, runs great, but I know there is an air leak either around an injector or the intake manifold itself, so when it is really cold, it will not want to idle without help.

So check for leaks first.
Also, since this is a tech thread, what is the vehicle and mods?

[s1ngletracker]

The car is for all intensive purposes, bone stock. 93 Tsi AWD with a 7 bolt.

I am currently replacing the head and head gasket, i'm going to make sure all boost leaks are addressed when that is done, and I'll update the thread.

[89_Colt_GT]

mine takes 10 turnovers to start and i need to let it warm itself up too. when its warmed up it'll start right away. Can't it just be beaten on and run everyday :/