PD TDI's Hard to Start First Time in the Day, No Problem Thereafter All Day

Carl Ulli

Well-known member
Joined
Feb 19, 2009
Location
Oshawa, Ontario
TDI
2005 Jetta Wagon TDI (My Daughter's now); 2012 Highline Jetta TDI; 2012 Golf Wagon
Dear Friends in the TDIclub,
I am a newbie to the club. I met several of you at TDIfest 2009 and based on all the posts I have read and studied, I have to say, I am truly impressed at how helpful the TDI community is to one another. Now I would like to be helpful to my new friends at TDI.
History:
My father-in-law has a PD TDI in a 2005 Jetta Wagon since it was new. He has had his car in the shop (dealership) many times to try to isolate the starting issues he has had with it. Now the warranty is expired and so he asked me if I could find some advice from my new friends at the TDI club. I read many of your posts and threads, learned a lot about both his PD and my older ALH, and now I want to share how we finally fixed his starting problem.
Symptoms:
Your fuel tank is about ¼ full, you get in the car in the morning to start it for the first time in the day. It fires up and immediately tries to stall and, and unless you hit the accelerator pedal you may or may not be able to keep it running. If it does stall, you crank and crank and crank it forever, it seems, till it finally starts. When it finally does start you could turn it off, even after about 5 seconds and it would start perfectly every time, all day – provided you don’t let it sit too long; like for 2-4 hours, or so. Then after sitting all night it will be the same problem all over again.
Do This Test:
Take a needle nosed vice-grip and when you have parked your car at the end of its’ driving day pinch off the fuel supply line between the fuel filter and the tandem pump. Try not to over pinch the hose so as not to do permanent damage to it, but you need to completely stop the flow. Tomorrow morning, be sure to remove the vise-grip pliers before trying to start the engine. If it starts, and stays running without a hitch, then you need to install a check valve as shown below.


I suggest you clamp your vise-grips right there where the check valve is, since the hose will be cut there anyway.

(At this point I think I should insert an interruption to the thought line of this post. I have read several posts from others who have had starting problems and found a totally and unexpected diagnosis. It seems, therefore, to be wise to do this test several times to verify that the problem is consistently and always occuring on the first start of the day, as the title specifies. ie: suppose you simulate a check valve with the vise-grip several times, and sometimes the engine still doesn't start, and it happened to be wet out that day, or whatever, - then you may be interested in this link http://forums.tdiclub.com/showthread.php?t=213503.)

Now back to this post.
Let me explain why this works. The tandem pump is driven by the camshaft and has seals in it to separate two independent pumps stacked together and using a common shaft. The left side of the pump develops vacuum for your power brakes and all the vacuum servos such as the EGR valve and Turbo controls. On the right side of the tandem pump (as seen in the photo below, not actual as in the car) is the fuel pump section. So when you let your car sit overnight the little seal between the vacuum chamber and the fuel chamber lets tiny amounts of air in. The weight of the fuel in the fuel line wants to fall back into the tank, and as the air slowly, ever so slowly, creeps in the fuel flows backwards – back towards the tank. If the tank is full and the rear end of the car happens to be much higher than the front of the car this problem doesn’t show. If however, the tank is only ¼ full, and the front end is higher than the rear, the problem is magnified. In this case the engine would certainly stall after initial start-up. Why does it start at all? There is still some fuel in each injector pump jet and the fuel supply line between the mechanical pump and the individual injector pump jets. The engine starts, uses up that little bit of fuel, and when no more new fuel follows due to the air lock, which had all night to develop, it stalls.

In this picture just imagine the shaft seal lets in air from the vacuum side to the fuel side.

Having the check valve in this line prevents the fuel’s weight to “pull” air past the seal causing the airlock. I would have preferred to have the check valve right there in that short bent hose to get it closer to the problem area, but space looked like an issue, and secondly, with the valve next to the filter, it will make filter changes easier in the future. The next photo is the valve and its’ package so you can recognize it easily.
(9/16" clamps not supplied)
The next thing is where to find this baby! I have done some research and so far this is what I have come up with. You will have to look around a bit in the world, depending on where you are. The following is an e-mail reply to me from the factory in Italy.


Dear Mr. Fulda
We thank you for your reply and are pleased that you have solved your problem with one of our products.
Our distributor in Canada is;
ADP DISTRIBUTORS INC.
18940 94TH AVENUE
SURREY, BRITISH COLUMBIA jld@adpdistributors.com
THEY ALSO HAVE A BRANCH IN ONTARIO
ADP DISTRIBUTORS INC.
398 CANARCTIC DRIVE
NORTH YORK, ONTARIO
For North America our Distributors are
U.S. DIESEL INC.
4243-A ROAD TO THE MALL
FORT WORTH - TEXAS
USA UNITED STATES bradg@usdiesel.com
or
KENDIESEL INC. / KENPARTS CO.
6 KILMER COURT
EDISON,
USA UNITED STATES carol@kendiesel.com

For other locations contact the factory itself at info@rased.it.
 
Last edited:

Carl Ulli

Well-known member
Joined
Feb 19, 2009
Location
Oshawa, Ontario
TDI
2005 Jetta Wagon TDI (My Daughter's now); 2012 Highline Jetta TDI; 2012 Golf Wagon
Thanks greengeeker

Well I finally got it.:) That was a steep learning curve for me. Many attempts at getting the sizing right, and some photo edits.

Anyways, I am curious to hear from anyone out there who tries this if this could be the end of the lift pumps burning out in the fuel tank. Also consider that with the check valve in there from now on if the lift pump does fail nobody would ever know until the day they run the tank empty and can't reprime the system using the lift pump electrically. Get the mighty vac out and do it manually, save yourself the big bucks!;)
 

bf1967

Veteran Member
Joined
Mar 19, 2007
Location
Burlington, Wisconsin
TDI
2005 Golf
Was the lift pump ever replaced in the car? There is a check valve in the canister that is intended to keep fuel in the canister when the pump shuts off so that the pump doesn't need to establish a prime on the pump. When the tank gets low, the canister won't fill from the top

There is a great thread here by DanG144 that explains it all in case you haven't already read it.

Bob
 

Geomorph

Veteran Member
Joined
Oct 17, 2007
Location
Sacramento, CA
TDI
2005 Golf and 2002 NB
I have an ALH that is having a similar issue. After it sits for about three or four days, it takes several seconds to get started the first time but then starts right up after that even after sitting overnight for one night. I have changed the battery, measured for battery drain, measured plenty of alternator voltage, so now I think that a little bit fuel is just draining back to the tank. I also changed the fuel filter in case it was the o-rings at the tee but that didn't fix it either. I will do your vise grip test when it is going to sit for a few days. Would there be any value in installing a check valve like this on an ALH? Thanks.
 
Last edited:

Carl Ulli

Well-known member
Joined
Feb 19, 2009
Location
Oshawa, Ontario
TDI
2005 Jetta Wagon TDI (My Daughter's now); 2012 Highline Jetta TDI; 2012 Golf Wagon
PD TDI Hard Starting First Time in the Day, No Problem Thereafter

bf1967 said:
Was the lift pump ever replaced in the car? There is a check valve in the canister that is intended to keep fuel in the canister when the pump shuts off so that the pump doesn't need to establish a prime on the pump. When the tank gets low, the canister won't fill from the top

There is a great thread here by DanG144 that explains it all in case you haven't already read it.

Bob
Yes, my father-in-law thinks they did replace it and the problem went benign for only a short time and then came back. (VW cancer!? eh?)

And Yes again, I studied DanG144's post with great interest before doing my post. It looked to me like the check valve in the lift pump unit is a kind of fragile little rubber thing which maybe doesn't differ much from the flap valve in a toilet -- and you know how good they are. That is why we should all watch with great anticipation how these PD's do using the in line check valve I used. Also, in my experience with Moffett forklifts and their Kubota engines, when the electric fuel pump quits nobody is ever the wiser until the day they let it run out of diesel and can't get it going again. I am really really curious as to whether my post could be the beginning of the end of a constant replacing of these lift pumps. If you don't lose prime, the engine will run; that's all there is to it.

Best of luck, Carl
 

Carl Ulli

Well-known member
Joined
Feb 19, 2009
Location
Oshawa, Ontario
TDI
2005 Jetta Wagon TDI (My Daughter's now); 2012 Highline Jetta TDI; 2012 Golf Wagon
PD TDI Hard Starting First Time in the Day, No Problem Thereafter

Geomorph said:
I have an ALH that is having a similar issue. After it sits for about three or four days, it takes several seconds to get started the first time but then starts right up after that even after sitting overnight for one night. I have changed the battery, measured for battery drain, measured plenty of alternator voltage, so now I think that a little bit fuel is just draining back to the tank. I also changed the fuel filter in case it was the o-rings at the tee but that didn't fix it either. I will do your vise grip test when it is going to sit for a few days. Would there be any value in installing a check valve like this on an ALH? Thanks.
Quite Possibly. I originally thought it would be highly unlikely but I've been corrected on this. I will leave the following comment intact because it is not totally wrong, but please read it with a discerning mind. An ALH engine has an injection pump which is very different in design than Pumpe Duse (German for pump jet) TDI's. If you look at my second photo again and compare the same area in your ALH engine you will see that your engine does not have two pumps stacked together in tandem and separated by a skinny little seal. The PD's have that extra mechanical fuel pump which the ALH does not have. Too bad for the space limitation of the body design in that tandem pump so that little skinny seal has to keep the diesel fuel separate from the vacuum pump. When everything is new it holds out ok but now things are not quite so good any more. The seal is probably only made to keep fuel in the fuel side as the vacuum side might try to "suck" fuel into the vacuum pump, and the seal can do that very well during engine operation. But while the engine is stopped the little seal wouldn't be so good at stopping air from trickling in towards the fuel side. Remember all seals have a high pressure side and a low pressure side. I think there should have been two seals in there, one facing each way to stop air from getting in while the engine is stopped and to stop fuel from transferring to the vacuum side while the engine is running. Since your ALH does not have this tandem pump setup there is not a place where air can leak in to the fuel line. This comment (italics) needs the correction. Apparently the shaft seal to the injecton pump does let air in with age.

Now, getting back to your very real concerns:
My first response to your battery reference was this, "Did your engine not crank over fast enough?" A diesel needs to crank over fast enough to fire so that there isn't time for compression loss. But since you have no problem all other times I wouldn't blame your battery for your problem. Perhaps you can try the following:
Assuming your injectors are not absolutely tight and the fuel reserve which they should hold within their bodies forever has leaked out and dribbled onto the top of the pistons - ok - so now you need to recharge each of your four injectors with new fuel before you actually can begin the starting process. Do this: Turn your ignition key all the way over to crank the engine just long enough so that each piston passes by Top Dead Denter one time. I mean by that "Do not give the glow plugs a chance to heat up". Now that each cylinder has puffed one time only, stop cranking. By now each injector will be recharged with fuel, so you can now let the glow plugs heat up and you will see that when you start cranking, the first cylinder that comes up to TDC will fire up the engine! Remember this trick in the dead of winter. I do it all the time with my ALH and it really saves on battery power. This is my winter starting trick but I shared it with you here, even though winter is not yet here, as a test to try to determine if your injectors are not clean and tight. If this test works for you I suggest you try a diesel purge to clean out your injectors. You can read up on that in the How To's forum.

One more note: In most cases TDI's don't let you do this trick because they tend to start before you get a chance to stop cranking. And certainly with PD TDI's, because they have much faster glow plug preheating times nowadays, you will likely seldom see this trick work the way it does on a Lister Petter engine.
 
Last edited:

bf1967

Veteran Member
Joined
Mar 19, 2007
Location
Burlington, Wisconsin
TDI
2005 Golf
Carl Ulli said:
Yes, my father-in-law thinks they did replace it and the problem went benign for only a short time and then came back. (VW cancer!? eh?)

And Yes again, I studied DanG144's post with great interest before doing my post. It looked to me like the check valve in the lift pump unit is a kind of fragile little rubber thing which maybe doesn't differ much from the flap valve in a toilet -- and you know how good they are. That is why we should all watch with great anticipation how these PD's do using the in line check valve I used. Also, in my experience with Moffett forklifts and their Kubota engines, when the electric fuel pump quits nobody is ever the wiser until the day they let it run out of diesel and can't get it going again. I am really really curious as to whether my post could be the beginning of the end of a constant replacing of these lift pumps. If you don't lose prime, the engine will run; that's all there is to it.

Best of luck, Carl
Yes, the flapper (check valve) in the lift pump is a glorified toilet flapper. I'm not sure how tightly those seal over a longer period of time. I know my pump was full of fuel when I pulled it recently, but who knows how long the fuel would stay in there if the tank level was lower.

Since your theory is that the seal in the tandem pump is leaking ( if I'm following this) resulting in the fuel draining back, do you know if that seal is replaceable?

Bob
 

Geomorph

Veteran Member
Joined
Oct 17, 2007
Location
Sacramento, CA
TDI
2005 Golf and 2002 NB
Thanks for the reply Carl. I think I might have had an air leak in the fuel line that goes into my injection pump. I was just now looking at it and noticed that the spring clamp that attaches the line to the pump was bent so that it did not wrap all the way around the hose. It looks like someone tried to pry it off. I took it off, pulled the hose, put a new spring clamp on it (I actually had an extra one lying around) and put it back together. The hose came off much easier than when taking a hose off the fuel filter, so it did not seem to be clamped very tightly. We'll see if this fixes it. Either way, thanks for the information and I will keep your injector recharging trick in mind. I may need it tomorrow morning since a little bit of fuel dribbled out of the hose while I was pulling it off.

I'll be following this thread with interest as my other car is a BEW and I may have to deal with a failed lift pump some day. Thanks again.
 

Carl Ulli

Well-known member
Joined
Feb 19, 2009
Location
Oshawa, Ontario
TDI
2005 Jetta Wagon TDI (My Daughter's now); 2012 Highline Jetta TDI; 2012 Golf Wagon
Geomorph said:
...Either way, thanks for the information and I will keep your injector recharging trick in mind. I may need it tomorrow morning since a little bit of fuel dribbled out of the hose while I was pulling it off.
Umm, I 'm not so sure you can use the trick successfully in that way. Here is why: When a "dirty" injector body leaks down into the combustion chamber the body of the injector drains off only a bit. The tip of the injector nozzle has a fine little valve which the very high injection pressure must overcome to squeeze the fuel charge by it thus causing the fuel to atomize. When I say some fuel leaks by there, it is such a minute amount that you could hardly measure the quantity. The result of that is that the precharge pressure inside the injector body is lower which means the next injection charge will be missing a small portion of it's charge so you would see less of a spray of atomized fuel. This might not be enough to start an engine. Your situation is different because the airlock you introduced into the line is a), much bigger, and b), it is on the upstream side of the injector "circuit", for lack of a better word. I have to admit I'm groping about in the dark a little bit here. I imagine there would have to be two valves in an injector body kind of like a toy squirt gun. An airlock in a fuel supply line upstream of an injector is still outside of the injector. These are very hard to get rid of without opening the high pressure fitting at the injector - because air is compressible, elastic, "bouncy" making it hard for an injection pump to overcome that; especially since it only pushes such miniscule amounts at any one time. A microscopic airlock inside an injector body can be easily "pushed through" because of the squirt gun effect that you have in the injector.
 
Last edited:

Carl Ulli

Well-known member
Joined
Feb 19, 2009
Location
Oshawa, Ontario
TDI
2005 Jetta Wagon TDI (My Daughter's now); 2012 Highline Jetta TDI; 2012 Golf Wagon
bf1967 said:
...Since your theory is that the seal in the tandem pump is leaking ( if I'm following this) resulting in the fuel draining back, do you know if that seal is replaceable?

Bob
I don't know the answer to this. My gut feeling is that because the world has become a throw-away society, and a remove-and-replace do it quick 'cause time is money kind of society all in one, you can only get the whole tandem pump as a complete unit. I like the way you think though. I sure would prefer to replace the little seal than to spend the big bucks on a whole pump. Since I don't pay myself wages, I'd rather spend the time in order to save money. That's how I grew up too.

The in line check valve works very well. A mechanic friend of mine shared it with me and his customer never had a problem again, and my father-in-law is happy his problem is now resolved, so that is two successes that I can refer to. I believe when a few more TDI club members try it, and find it works, it will become the standard way to resolve the issue.
 
Last edited:

Colorado_Al

Veteran Member
Joined
Oct 11, 2007
Location
Boulder, CO
TDI
2005 Jetta Wagon MK4 5SPD
Carl,
I'm going to try your check valve mod once I get the part, hopefully this weekend. I have had hard starting in the morning with my 05 Jetta TDI PD. I thought it was due to the Glow Plug recall, but I'm testing your theory tonight with some vise grips. I'm also putting a manual switch on my fuel pump so that I can run it without cranking the engine to see if I can get it to prime.
Will let you know how it goes.
Thanks!
Al
 

Carl Ulli

Well-known member
Joined
Feb 19, 2009
Location
Oshawa, Ontario
TDI
2005 Jetta Wagon TDI (My Daughter's now); 2012 Highline Jetta TDI; 2012 Golf Wagon
Hello Colorado Al,
Sounds good to me. Your car and your starting issues are exactly like my father-in-law's were. When you get to your glow plugs and the diagnosis for them be sure to read up on all the threads regarding that. Dad had the bad luck that the dealership put all new glow plugs into his and they were the wrong ones. For that year car there was an update and you have to know which glow plugs you actually have, the 5v or the 7v ones. Then you have to get a Vag Com to reflash the ECM to correspond to your new set of glow plugs.

And now back to the fuel side of hard starting. I received the following email from dirtyexhaust who is dealing with the same starting issue. He learned something significant for all of us to take note of.


Carl - I think you're on to something with the check valve. I stopped at the dealer last night that I purchased my lift pump from (I had to buy it from them I saved 70 bucks) and we looked up the illustration for the fuel assembly. The parts guy could not find anything that called out a check valve so he called over a mechanic and this guy said there was a built in check valve in the rear fuel line assembly. The Mechanic said to fix the same problem on a different car the Tec support said to replace the rear fuel lines because there was a check valve inside that went bad. He said when he got the part in he couldnt see the valve but he could only blow air one way thru the line - and it fixed the starting issue. He printed off a "Tandem Pump, Checking" procedure and one of the lines says that "The check valve in the fuel supply hose must be ok" So this proves there is one there its just not called out on any illustrations. They want $150 for the fuel line assembly so I'll be trying your idea first. Thanks a lot for your help. I'll let you know if this works. - Dennis.

I wrote something above in error. Nate, thank you for the correction.

PDJetta vbmenu_register("postmenu_2782020", true);
Veteran Member



Join Date: Nov 2003



Take note:

"Then you have to get a Vag Com to reflash the ECM to correspond to your new set of glow plugs" [voltage change from 7 v to 5 v].

Vag Com (VCDS) scan tools CAN NOT recode the ECU. This takes a chip tuner, or the official VW equipment to do this.

--Nate
__________________
2004 Jetta GLS TDI 5M Plat. Grey w/ Leather. RC Stage 2, G60/VR-6 clutch, steel skid plate, TDIHeater, CAT 2um fuel flter, Phat Noise, and VDO boost & volt guages.
 
Last edited:

Carl Ulli

Well-known member
Joined
Feb 19, 2009
Location
Oshawa, Ontario
TDI
2005 Jetta Wagon TDI (My Daughter's now); 2012 Highline Jetta TDI; 2012 Golf Wagon
Carl Ulli said:
... He printed off a "Tandem Pump, Checking" procedure and one of the lines says that "The check valve in the fuel supply hose must be ok" So this proves there is one there its just not called out on any illustrations. They want $150 for the fuel line assembly so I'll be trying your idea first. Thanks a lot for your help. I'll let you know if this works. - Dennis.
This is very interesting indeed. I think a check valve in the tank-to-filter line, if it is so streamlined that you can't even tell it is there must be pretty small and also it would be vulnerable to the dirt that might be floating around in the fuel tank. By adding my inline check valve post filter we can ensure that it will not be affected by particles big enough to hold it open. The pre filter check valve is not protected in this way.
 

PDJetta

Top Post Dawg
Joined
Nov 6, 2003
Location
Northern Virginia
TDI
'04 Jetta GLS TDI Pumpe Duce Platinum Grey w/ Leather
Take note:

"Then you have to get a Vag Com to reflash the ECM to correspond to your new set of glow plugs" [voltage change from 7 v to 5 v].

Vag Com (VCDS) scan tools CAN NOT recode the ECU. This takes a chip tuner, or the official VW equipment to do this.

--Nate
 

Colorado_Al

Veteran Member
Joined
Oct 11, 2007
Location
Boulder, CO
TDI
2005 Jetta Wagon MK4 5SPD
Yay! Carl!!!

Carl, you are right on on this one!!!
Again I clamped the fuel hose overnight, and when I started it this morning at 25 degrees (even without my frostheater plugged in) it turned right over!
I had suspected that it was losing prime for a while, but had not gone this far to troubleshoot.

I will be adding a check valve this weekend!
I wonder how many people have been talked into a new fuel pump and labor (and talked out of $400) by the VW dealer just because their check valve failed?

A 10 dollar part and 5 minutes to fix...

Thanks again Carl!!!
 

dirtyexhaust

Active member
Joined
Oct 21, 2008
Location
Waterford, Michigan
TDI
2010 Jetta TDI
well i put my check valve in the supply line from the tank and it helped a lot - but didnt totaly cure the starting problem. it starts then stalls but it starts up after just a few cranks. i might try adding another valve on the return line. i went with the larger 10mm size so it wouldnt restrict flow that much so i think 2 of them will be ok.
 

MkVer

Veteran Member
Joined
Oct 18, 2010
Location
NM
TDI
MkV Jetta BRM
So I did the overnight clamp off and my engine fired up easy as can be. Here I thought winter was to blame, but when it started happening in 60F alabama weather on a business trip I knew I had other issues.

So does any one know the longevity of the tandem pump? I worry that putting the check valve in will merely mask the underlying problem of a failing tandem pump.
 

kpiazzisi

Well-known member
Joined
May 11, 2009
Location
tampa, florida
TDI
jetta 2006
I was wondering the same thing myself. I understand half the pump is vacuum and half is fuel, but where does the oil come into the picture. According to the VW manual if the tandem pump fails, fuel can mix with oil. Here is the exact wording from the VW manual. Please explain for those who understand this pump way more then I do.

"The tandem pump must be checked for internal leaks between fuel side and oil side after reinstalling a used tandem pump, for example after renewing or repairing a cylinder head and/or when installing a “short” engine. When leaking it is possible for the fuel to mix with the oil, which may cause the engine to fail. "
 

jasonmichef

New member
Joined
Aug 9, 2010
Location
Owosso, MI
TDI
2002 Jetta
2002 ALH loosing prime

I have a fuel filter T and O-ring on order. Curious about installing the inline check valve on my car? Car start if I drive it regular but sits more than 24 hrs I need to bleed injectors.
 

TdiTaff

Veteran Member
Joined
Apr 19, 2010
Location
UK / France
TDI
2007 Golf TDi 5Speed
Haven't seen this thread before and have been through the GP recalls with little success.
It's definitely worth a try and $10-$15 to install with no down side.
 

kpiazzisi

Well-known member
Joined
May 11, 2009
Location
tampa, florida
TDI
jetta 2006
I just discovered that there is a link between my failed tandem pump and my car producing white smoke. I have had a failed tandem pump for a few months now. I simply just let the car crank for a minute and it eventually starts. A couple of times now the car has started producing white smoke. I realized that changing the oil solves the problem. I drained my oil yesturday and had 5 quarts after I drained the drain pan into a 5 qt container. I figure there was probably another half a qt trapped in the motor. I only put 4 qt in the engine when I changed the oil. What is happening is that I believe fuel is mixing with the oil due to a failed tandem pump. Here is what it says in the VW manual.

"The tandem pump must be checked for internal leaks between fuel side and oil side after reinstalling a used tandem pump, for example after renewing or repairing a cylinder head and/or when installing a “short” engine. When leaking it is possible for the fuel to mix with the oil, which may cause the engine to fail. "
 

sc00byd00311

Veteran Member
Joined
May 31, 2012
Location
KC MO
TDI
04 Jetta (Zubie)
I just discovered that there is a link between my failed tandem pump and my car producing white smoke. I have had a failed tandem pump for a few months now. I simply just let the car crank for a minute and it eventually starts. A couple of times now the car has started producing white smoke. I realized that changing the oil solves the problem. I drained my oil yesturday and had 5 quarts after I drained the drain pan into a 5 qt container. I figure there was probably another half a qt trapped in the motor. I only put 4 qt in the engine when I changed the oil. What is happening is that I believe fuel is mixing with the oil due to a failed tandem pump. Here is what it says in the VW manual.

"The tandem pump must be checked for internal leaks between fuel side and oil side after reinstalling a used tandem pump, for example after renewing or repairing a cylinder head and/or when installing a “short” engine. When leaking it is possible for the fuel to mix with the oil, which may cause the engine to fail. "
Thanks for the post. Mine is also leaking and my guru says that it is a fairly common issue with the PD engines. Are you replacing yourself or taking it to a shop. I hear it's only four bolts but it has vacuum hoses and fuel lines.
 

magna413

Well-known member
Joined
May 2, 2012
Location
Võru, Estonia, Europe
TDI
VW Golf MKV 2.0TDI 4Motion EURO
Hello, any news on this?
Is it possible to fix the internals in pump? I know there are no OE codes for internal seals but i've heard that it is possible to change the o-ring with o-ring from BEW??? oil filter o-ring?
 

hanke

Member
Joined
Oct 1, 2006
Location
Burlington, Ontario
TDI
2006 Golf TDI GLS Automatic BEW
Hello...wondering how the installed Check Valve has been working since its been 2 yrs now. I have a situation in which I have:

Cold Start - No Problem
Warm/Hot Start - Excessive Cranking (wait about 5 mins after hot shut off will cause long cranking)

If engine is restarted within say 1 min of Hot shutdown, it fires up no problem. Usually anything longer will cause excessive cranking.

No leaks exist at the Tandem Pump and I pinched off the line when hot waited the req'd time to cause long cranking, removed pinch and it started up no problem.

Lift pump, Coolant Temp Sensor, Fuel Filter all changed recently and no check engine light displayed.

Thanks
 

hanke

Member
Joined
Oct 1, 2006
Location
Burlington, Ontario
TDI
2006 Golf TDI GLS Automatic BEW
I forgot to mention...I am pinching the return line before going into the Fuel Filter T connection. This allows hot restarts no problem.

If I pinch off the Feed side going to the pump, no change is noticed and cranking exists.

So, I guess pressure is maintain in the fuel system back through to the feed side of the pump by doing this test. It would seem the Tandem pump is not maintaining the pressure with hot engine start yet with cold engine no issue. Perhaps the pump is defective since its not maintaining pressure to the injector pump when hot. (leaking) When cold start there enough fuel present to start!
 

hanke

Member
Joined
Oct 1, 2006
Location
Burlington, Ontario
TDI
2006 Golf TDI GLS Automatic BEW
Problem Solved !

It turns out after all the checks etc....the fuel had gasoline in it. As a result when hot and firing it would not ignite until after long cranks.

Fuel system has been purged and all is working again. Obviously it was a bad fill up of diesel fuel so really cant get around it, it happens, but now the symptons are known if it happens again.

Apparently an easy test is to take a fuel sample, and try to light it with a match, if it burns its has gasoline in it, diesel will not burn in unless in a uncompressed state.

Thanks for any advice that was offered and enjoy reading the forums.
 

PDJetta

Top Post Dawg
Joined
Nov 6, 2003
Location
Northern Virginia
TDI
'04 Jetta GLS TDI Pumpe Duce Platinum Grey w/ Leather
"It turns out after all the checks etc....the fuel had gasoline in it. As a result when hot and firing it would not ignite until after long cranks."

Wow. It must have been vapor locking in the fuel line, but the percentage of gas low enough to avoid detection and allow the engine to run.

--Nate
 
Top