Hard COLD start, bad ISC or something else??

[tsi1991awd]

91 Talon TSI AWD...it is hard to start in the morning. Its been cold here lately (WA) and it takes 3 or 4 times before the car starts. Then when it does start sometimes it'll stutter at a really low RPM before it starts warming up normal.

This is only on the first start of the day. Every other time it starts with no problems at all.

What could it be? I'm changing the spark plugs this weekend and the fuel filter next weekend. I have read the coolant temp sensor can cause it to have a hard start but this is only one time. It will start fine every other time. It idles fine, drives fine. Doesn't stall, die, etc. So I have no idea....

 

[DSM1G90]

Yea, "Harbour Fright" - DIY tool heaven emporium for the budget minded. Hit the place just right and you can find great stuff in there.

With compress checkers, just make sure that you have the hose variety with the sparkplug thread end to secure the testor to the cylinder to get more accurate readings. For that come in handy in many motor applications instead of using the coned end variety.

 

[r1991_4g63t]

Yea, "Harbour Fright" - DIY tool heaven emporium for the budget minded. Hit the place just right and you can find great stuff in there.

With compress checkers, just make sure that you have the hose variety with the sparkplug thread end to secure the testor to the cylinder to get more accurate readings. For that come in handy in many motor applications instead of using the coned end variety.

and dont thread it in too much, just barely snug it. mine is now stuck in the head til i pull it off

 

[tsi1991awd]

So what are you supposed to do? Start the car with it in there or?

 

[interex]

no, you take the plugs out and use the gauge on each cylinder and turn the engine over. you can use the ignition if you like but the car wont start.

 

[tsi1991awd]

I don't think I follow.....take spark plugs out, put gauge in the cylinder, then turn the ignition to the on position?

 

[DSM1G90]

Be kinda nice if you had a partner hit the key while you're outside holding the testor. For you only need a few turns of the motor to get your readings, but it can be done by yourself. For hooking up a remote starter button with the starter behind and underneath everything is rather tough to do.

 

[r1991_4g63t]

I don't think I follow.....take spark plugs out, put gauge in the cylinder, then turn the ignition to the on position?

take plugs out, remove mpi fuse so you dont wash the rings with gas, put guage in, crank it a couple times while holding your foot to the floor and see what the guage says

 

[tsi1991awd]

What's the mpi fuse?


And is there a fuel pump fuse anywhere? I don't see one and I'd rather not take my back seat out to disconnect the fuel pump (when I do my fuel filter)

 

[r1991_4g63t]

the mpi fuse is the fuel pump fuse. i;'d have to do some checking to find out which one it is exactly.

i just remember that wheni did mine i just unplugged the resistor pack on the firewall so the injectors didnt fire.

 

[tsi1991awd]

Will it say mpi on the fuse box cover? Because I don't think I remember seeing that

 

[tsi1991awd]

This morning was kind of weird...it was cold out but not AS cold as it has been lately. Car was sitting for 10 or 11 hours. Started up on the first try. I don't get it.

Could it have something to do with the ignition switch? Because obviously it is retaining fuel pressure since it started right up this morning....or its just a fluke. Don't know.

 

[DSM1G90]

Not the switch, yet I call it the weather as well as a fluke. Just have to keep an eye on things.

 

[tsi1991awd]

Not the switch, yet I call it the weather as well as a fluke. Just have to keep an eye on things.

Yea I don't know man...maybe it just totally hates the cold weather and gives me a hard time. No other car I've owned has done this...but I guess it just has its own personality.

 

[r1991_4g63t]

mine seemed to be fine if it was over 15* but if it was 14* watch out

 

[tsi1991awd]

OK, well I believe the problem has been fixed. This past Saturday I changed the fuel filter (which was REALLY easy btw...don't know what everyone says its so hard) and the car had a performance increase. I was shocked because I dumped the gas out of the old filter and it was clear...ran water through it, and it was clear. But the filter was definately clogged because my car has never pulled like this before.

After I got home (around 11) I parked and Sunday used my wifes car to go out. Came back, and started the car up about 8pm. So the car had been sitting for 21 hours. Fired up on the first try. Came home a bit before 9pm, let the car sit until 6:45 this morning, was cold out...frost on the ground, and a bit of water that had frozen on the road. Got in, fired up on the first try. I thought HELL YEA, fixed! So hopefully today after work it doesn't let me down.

I do believe it was just the fuel delivery problem...the gas wouldn't pass through the filter enough to start the engine. The CTS WAS shot, like I said. Had no reading at all...this may have contributed a little bit to the problem, but the majority of my problem lied at the fuel filter.

Thanks for everyones help!

 

[DSM1G90]

Good luck. Now, have some "DSM" fun with your ride!

 

[tsi1991awd]

Thanks bro....already having a bit of fun. Its a lot peppier, gets up and scoots!

 

[tsi1991awd]

Well, bad news...its not fixed. It was starting great for a while there. Today, went out....colder than usual out and it took about 8 tries before it started. It started once and was idling then died. Then I started it again and it was fine, idling warming up. What the hell?

I'm thinking fuel delivery issue, but I don't know exactly what. Maybe ill run a bottle of injector cleaner through when my tank goes empty and see if that helps anything.

 

[djordan97]

have you checked your isc? if it's not working then it'll be in a stuck position and could be the cause of the hard start because it's not letting enough air through as well as cleaning your throttle really well.

 

[tsi1991awd]

have you checked your isc? if it's not working then it'll be in a stuck position and could be the cause of the hard start because it's not letting enough air through as well as cleaning your throttle really well.

It could be the ISC...I'm not sure. It starts up fine every other time except that morning start. Also, lately when it has trouble starting, when it is idling at warm up, it will fluctuate. It'll be at 2000 warming up then drop down to about 1600 or 1700 then go back up to 2000. It does this repeatedly, back to back. I usually hit the throttle for maybe 10 seconds, keeping it at 2500 then let off and it is fine after that. That could be an ISC issue.

How would I go about testing it? Or is there no real way to do so aside from buying another one?

 

[tsi1991awd]

I had a cold start issue before. Car wouldn't start when it was cold in the morning...and morning only (first start of the day) I changed the CTS (didn't help) and fuel filter (helped for a few days) and now I'm back at square one.

Yesterday, it was a bit colder than usual...tried to start, nothing. Tried 10+ times and it finally started...was starting to idle at 2,000rpm to warm up and then it just died. Started again and it was around 1,000rpm and started to die so I gave it a bit of gas and then it went up to 2,000 and idled until warm.

Also, I usually have a surge when it is warming up (again, first start after car has been sitting 8+ hours and very cold outside) it'll be idling at 2,000 then drop down to 1,700 and back up to 2,000....does this repeatedly and if I give it gas, hold it around 2,200-2,300 for maybe 10 seconds and let off the gas then it'll stop surging and warm up normal.

Now, would a bad ISC cause this? Like I said, this does not happen any other time except when the car has been sitting for 8+ hours and its cold outside. All other times the car starts fine. It idles fine, drives fine...there is NO SURGE at idle, other than what I mentioned above when its cold.

 

[PIMking]

well I blocked off my ISC and FIav. I have to hold the throttle down for about 1 min before I can take off.

I also have Link.

 

[SnowBird]

Is your FIAV working properly? I wouldnt think itd be the ISC, because you said if you bump the throttle and once its warmed up its fine. My expieriences with ISC motors gone bad are constant surge ALL THE TIME at idle. Just with the cold and all it makes me think of the FIAV. Do you still have your FIAV hooked up?

 

[360glitch]

From what I understand about the FIAV it is what helps you on those cold starts. I'm not really familiar with how they work so I'm not sure if it can "break" but I would definitely make sure it's not blocked off or anything. Wish I had more info for you. Try searching about the FIAV.

 

[rich3389]

Probably a bad FIAV, I would try a new throttle body. Mine had cold start issues and would surge when cold and my FIAV was leaking coolant into the intake manifold.