Harder cold starts, stalling problem

[thecause17]

I've been searching the forum here for some answers, but can't seem to find anything that is similar to my scenario.

For the last two days Ive noticed that on a cold start, specifically the first start of the day, it takes longer than normal to start. It cranks fine, but takes 3-4 seconds to actually fire up. Usually the car starts almost immediately.

Also, the car stalled twice on me yesterday. Both times were in parking lots while coasting at low speed. ALso noticed some roughness at low rpms at the same time. No cel or any other lights except for the battery light after stalling for obvious reasons (no charging).

Hooked up VCDS, no faults present.

Info on conditions, temps have been mid 60's to mid 70's here the past few days. I filled the car up shortly before this, same station I always use. There's probably only 100 miles on this tank of fuel right now. Fuel filter was changed at 60k miles, currently have just under 66k. I'm thinking I may have gotten some bad fuel or water in with it. I may open the fuel filter canister this afternoon to take a look for water and/or metal shavings. This doesn't seem consistent with a failing HPFP as it's only been happening at basically idle. Fuel pressure at idle is consistently around 5000psi according to my scan gauge which reads right from the car's sensors. Hitting 26kpsi at full throttle higher rpms.

Was slow to start this morning again, but hasn't stalled on me yet and ran fine on the 20 miles or so I've driven it today.

What do you guys think my next move should be. Like I said, I'm going to open the fuel filter canister and have a look, and then rerun the fuel pumps via VCDS again to get out any air I may have introduced.

 

[thecause17]

Opened up the fuel filter canister, pumped all of the fuel out of it into a container...no water present. No metal flakes either.

 

[waltzconmigo]

cause---have you seen this thread? Check your intercooler.

http://forums.tdiclub.com/showthread.php?t=302863

 

[thecause17]

I've seen information on that before, but since my stalling and stumbling issues aren't at heavy throttle, when most people seem to be sucking the water into the engine, I can't see it being the problem. Plus the weather has been extremely dry here for weeks until today. I guess I can pull a hose to see what's in it. I remember in the past people saying they've been able to see oily residue at the hose connections on the intercooler. I just changed oil last week and remember specifically looking at that while I was under there and there were no signs of anything, all clean.

 

[waltzconmigo]

cause---its seems that you have VCDS, could provide the info. asked for by oilhammer in this thread? sounds similar. good luck.

http://forums.tdiclub.com/showthread.php?t=423194

 

[thecause17]

Yeah it shouldn't be a problem to look at some of that stuff. Rail pressure I can already see on my scan gauge and I haven't seen anything abnormal. As far as I can tell both of my electric pumps are working. I bled the system yesterday after checking the filter canister and they both appeared to be working, but I will see if I can look at anything else to confirm that.

I've actually had similar symptoms to those in the thread you posted such as the rough start up and sometimes the car has shut off right after start up, but then will restart and run rough for a few seconds. Ive never had a check engine light though. Ironically it's been fine today and has shown no abnormal behavior. Quick starts and no roughness at all. It's actually been fine since I checked and bled the fuel system. So there may be a connection, possibly air as mentioned in the other thread. However, I don't see air getting into the system without a noticeable leak somewhere, even at the canister with relatively low pressure there.

I don't know much about the fuel system on this car, such as how much rail pressure is needed at start up and how much is present in the rail on a non running engine. If not enough pressure is made before the HPFP immediately at the start up then I could see the HPFP experiencing cavitation and causing a loss in head pressure on the rail side, causing a stall or misfire. Also very unhealthy for the pump itself. This could definitely be caused by one of the other two pumps not working properly or having air in the system. Problem is, I don't know what the good specs are supposed to be to even compare anything to. The only thing I can do I guess is compare results during the problem period to when the car is running fine.

I'd like to take some live data with VCDS but need to look at relevant parameters to even monitor. I was going to look into fuel pressure and whatever injector monitoring can be seen as well as the other pump statuses/pressures if that's even available.

 

[ss~zoso~ss]

so this is ironic, i'm also located in Dover with the same exact car as yourself, even the same color!

and I've been having the same issue since earlier this year! (jan timeframe)

I thought it was the ol' water in the inter cooler situation, but winner vw didn't find anything in the hoses that looked abnormal

After driving this whole year so far i still have a slight roughness rpm fluctuation during initial start.

My car has 34k on it, so this has been a frustrating issue.

I'll keep my eye out on here, but if you find a solution to your problem please let me know via PM!

Jeff

 

[James & Son]

I don't have your car but I can through out some other possibilities.

Intermittent cam or crank sensor
Any of the temperature sensors; coolant, fuel, and Map
Glow plug post glow time after start.

 

[thecause17]

so this is ironic, i'm also located in Dover with the same exact car as yourself, even the same color!

and I've been having the same issue since earlier this year! (jan timeframe)

I thought it was the ol' water in the inter cooler situation, but winner vw didn't find anything in the hoses that looked abnormal

After driving this whole year so far i still have a slight roughness rpm fluctuation during initial start.

My car has 34k on it, so this has been a frustrating issue.

I'll keep my eye out on here, but if you find a solution to your problem please let me know via PM!

Jeff

I will keep you posted. I am replacing the pressure retention valve that's in the return line of the fuel injectors sometime this week when the part comes in. We will see how that goes and if it changes anything.

The car had been really consistent with having hard starts every morning for the last several days....until this morning. It had sat for a least 12 hours just like all of the other days, but it fired right up with no hesitation and no rough idle after it started. Only difference today was it was colder than it had been, and was in the 40's when I started it. Glow plug light actually stayed on for a few seconds today and it fired without problems. Any other day the glow plug light only stays on for about a second since it has been warmer temperatures.

 

[ss~zoso~ss]

i've had similar instances where it starts up completely normal, then a long chain of instances where it is bumpy like it usually is

where did you order the part from, i went out and looked at it on my car today and it seems so expensive for such a small little valve, and like you said strange that there aren't any clamps on that line

i found the whole line here:

http://www.idparts.com/catalog/product_info.php?products_id=4065

 

[ss~zoso~ss]

i'm anxious to see if that fixes it for you, even though that part is like 100 bucks, i'd do it in a heartbeat. I will do just that if it works out for you.

 

[thecause17]

i've had similar instances where it starts up completely normal, then a long chain of instances where it is bumpy like it usually is

where did you order the part from, i went out and looked at it on my car today and it seems so expensive for such a small little valve, and like you said strange that there aren't any clamps on that line

i found the whole line here:

http://www.idparts.com/catalog/product_info.php?products_id=4065

I ordered it from ECS tuning, was cheaper than that. I had about $95 in it after shipping. It should be here tomorrow. That pic in the link is actually the first pic I've been able to find of the part number. That is the same part number I ordered so I'm thinking I'll probably get the entire assembly as pictured in your link. If that's the case then it looks like it'll need to removed from each injector. If that's how they do it then I bet all the other connections are molded in place and that would be why no clamps would be needed. I'll have to look into how that detaches from the injector.

 

[ss~zoso~ss]

cool, please keep me posted, would be great if this fixes it!

 

[thecause17]

Update. I have installed the new pressure retention valve. It's a very easy job. It is a complete line setup as mentioned earlier. Releasing the lines from the fuel injectors is pretty easy and can be seen here:

http://www.myturbodiesel.com/wiki/fuel-injector-and-valve-cover-removal-cjaa-cbea-2-0-tdi-engine/

At the other end, the downstream side of the retention valve just pulls off of the rubber line. There shouldn't ever really be any pressure here so it's no surprise that it just pulls apart.

Upon releasing the first injector connection I expected some sort of pressure and fuel release, but found none. IF this valve is in fact supposed to maintain pressure for any extended period of time without the engine running mine was not doing this. My car sat for 24 hours prior. We've talked about this valve maintaining pressure for proper injector operation, but none of the documentation really specifies that this pressure is maintained during an engine off state or if the valve only acts as a regulating device during a running state. Depending on what that really means it goes one way or another whether or not my valve was working correctly. Only time will tell over the next several days and cold starts. Either way, wear safety glasses when pulling it off because I really don't know what kind of pressure was supposed to be there, if any.

Initial start up after replacing the valve and bleeding the fuel system was a hard start that took about 4 seconds for the car to turn over followed by around 15 seconds of rough idle before it smoothed out. This again doesn't say much yet, as the new valve and line still may not have had any fuel or pressure in it. I'm not sure bleeding the fuel system via VCDS by running the electric pumps would have pressurized this area on the return side of the injectors. I don't know enough about how the injectors work to know. My guess is that it didn't. If it did I don't think it would provide enough pressure to meet the minimum spec anyway so I think only running the car would have pressurized this part of the system properly.

So anyways, we'll see what happens. If this ends up fixing the issue I plan to dissect the old one to see if I can see what happened (foreign matter, cracked spring, bad seal, etc...)

 

[ss~zoso~ss]

alright, should know more tomorrow hopefully!

thanks for the update!

 

[thecause17]

It's going to have to be a solid week or more of good clean starts for me to be convinced that it's fixed, but of course if it's hard to start tomorrow morning then it's back to the drawing board.

One thing I forgot to mention in anyone changes this out. There is a tiny little o-ring on the injector where this return line connects. Make very sure that this o-ring is still there when you put the new line on, and that the line is fully in place before pushing the slide connector back down. It was fine for me, but I could see one of these o-rings sticking to the old line and going unnoticed, resulting in a not so nice fuel leak all over the top of your engine. I ran my engine for several minutes with the engine cover and foam damper off to check for leaks. Don't just throw it together and forget about it.

 

[waltzconmigo]

cause17---nice job getting at this quickly, let us how everything goes. also, may help if you linked the other thread in your first post to the one where JSWTDI09 suggested this so people do not have to go bouncing around with their research.

 

[thecause17]

cause17---nice job getting at this quickly, let us how everything goes. also, may help if you linked the other thread in your first post to the one where "Have Fun, Don" suggested this so people do not have to go bouncing around with their research.

Yes, I meant to do that earlier and forgot.

http://forums.tdiclub.com/showthread.php?t=424920

Yeah it sucks to take a $100 gamble, but I also don't feel like taking it down to the dealer and have them throw parts at it and guess as well. I've been down that road before and have found if anyone is going to gamble with my money it's going to be me.

 

[ss~zoso~ss]

absolutely, going to the dealer is a long and painstaking gamble esp when not under warranty and not knowing how much things are going to cost...

 

[waltzconmigo]

Yeah it sucks to take a $100 gamble, but I also don't feel like taking it down to the dealer and have them throw parts at it and guess as well. I've been down that road before and have found if anyone is going to gamble with my money it's going to be me.

You will not find any argument with that sentiment from me.

 

[thecause17]

Took the old valve apart just for kicks today. Sorry for the butchering, but I didn't know what to expect inside and wasn't initially sure on where to be cutting it open. Inside the canister is a strainer that I was unable to remove. The fuel travels from the line into the canister on the outside of the strainer and goes through it into the center where it encounters the ball/spring setup before leaving the valve. It looks to me as if the larger spring is overpowered by a set amount of pressure before the fuel is allowed to flow into the canister and the smaller spring acts mostly to retain that pressure below a certain point. Once the pressure drops below that threshold the ball(which is rubber) gets pushed into the small section of the tube that it's housed in and blocks off flow out of the valve. There's no way for me to tell if the valve was bad and the only points for failure I see are the springs.



Started great the day after the install. Started fine this morning too although it did take a tiny bit more time which I don't see as unusual yet. It wasn't near as long as it has been in the past. Still going to have to be several more days before I'll call it a success.

 

[tdiatlast]

You might want to charge your battery overnight, as it sounds like you've been putting unusual start-up stress on it. The alternator won't bring the battery up to full charge.
Hope you've solved your problem!

 

[thecause17]

I highly doubt my battery has been stressed given I'm not repeatedly cranking it before it starts. It would crank for 4-5 seconds and start. Only one attempt necessary. Whatever drain would have been caused by that was charged on the drive afterwards I'm sure of that.

 

[ss~zoso~ss]

wow, so no hiccups yet huh? I don't think I've had too many 'consectutive' successful starts since this issue started with my car, so this sounds good (fingers crossed)

So I take it you ordered the whole line like the link I posted? Looks like that valve couldn't be separated, same price anyhow

I had my car sitting for 2 days and started it today, and it took a good 1 second or so of cranking before it popped over, then went into the stumble dance for a good 3 sec or so...

Keep us posted, and thanks for doing this!

 

[thecause17]

Nothing to speak of really yet.

I ordered the same part number that you did, just from somewhere else. All of the lines are fused to the plastic connectors and valve through some process, heat crimping or something like that so no, none of it can be separated. Only the downstream side of the valve can be separated from the rubber line it connects to.

I sure hope this works, my luck with cars lately hasn't been so good. A month ago our Pilot had to have a cam and rocker arm replaced, and now it's going back in Saturday and the service writer told me possible pistons/rings replacement...all on a car with 70k miles and that has been maintained meticulously.

 

[tdiatlast]

I highly doubt my battery has been stressed given I'm not repeatedly cranking it before it starts. It would crank for 4-5 seconds and start. Only one attempt necessary. Whatever drain would have been caused by that was charged on the drive afterwards I'm sure of that.

If it's an original battery, I'd check it. 4-5 seconds doesn't seem long at all, unless the battery is compromised, and some of these batteries are failing within 3 years.
Just trying to help...

 

[thecause17]

Update:

It's been about a week now since the replacement and I still haven't had any starting issues. All the other variables have been the same as far as outdoor temps and the length of time the car has sat between starts. Seems good to go.

Thanks to JSWTDI09 who made the initial mention of this part in the other thread.

 

[waltzconmigo]

cause--- can you keep this thread updated periodically, there have been a few members who have "intercooler icing" symptoms but have not found any built up. thanks in advance.

 

[perrya]

So, I have the exact issue off and on, maybe once a week or so. The car sits overnight ((I am in Calif) and for no reason, the car will have problems starting. Just like the post. No codes. Changed the temp valves, checked compression (ok), new fuel pump and filters. It did it again after a week of being fine. Crank over, started and then stopped, then cranked for too long until started. After running a few miles, it is fine starting. The car can sit all day at work and will start up fine, but not in the morning, at times. Do you think replacing the Pressure rentention valve and return fuel line (or are these one unit?) will solve it? Gets great MPG. My car is an 06 with 200K.

 

[waltzconmigo]

perrya---you probably want to start a separate thread because the fuel systems between your '06 and the OP's '10 are different.