1,9 TDI PD hard to start - what´s next?

lindahl

Member
Joined
Dec 29, 2013
Location
Denmark
TDI
1,9 PD 101
Hi
Though this is my first post in here, I have been reading and searching this forum a lot for the past time, but haven´t found anything conclusive regarding my "hard start" issue.
So we have this really annoying problem with my wifes car (2001 1,9 TDI PD 101 ATD, 390.000 km). It began early this autumn, where it at first could be hard to start if left for a couple of days. The engine would initially fire up, but then die after only a second or so. Afterwards it needed around 10 seconds of cranking, before it would, reluctantly, start up. It seemed to help if you turned the ignition on and off 3-4 times before trying to start the engine at first (I would hear a remarkable squish when the pump primed the system). Later the problem got mere frequent, and the best way to start the engine would be to press the accelerator pedal simultaneously with the cranking. This meant that the engine would, typically, start at once, though idle could be a little rough for the first couple of seconds. The last month the problem worsened, which meant that even though the accelerator pedal was activated during start, the engine wouldn´t catch on immediately. When ever the car runs, it runs great, and mileage is spot on. Before autumn it fired up with out any problems, even in the coldest of winter. I replaced the fuel filter just before we went on summer holiday, and at the time I noticed that most of the fuel lines were very brittle.
After the starting issue began, I replaced all the rubber fuel lines in the engine compartment, the o rings on the fuel filter T (didn´t do this when changing the filter at first), and the tandem pump.
None of this improved starting noticeably. 3 weeks ago I then fitted a non return valve in the fuel feed line between the fuel filter and the tandem pump, and all of a sudden the starting problems were gone. Even when the car had been left for 5 days in a row it just started instantly. But unfortunately my luck was short lived. A couple of days ago after a Christmas visit, the issue was back even worse. The car had been parked on a slope, with the front facing up. It was a real pain to get started. Then today I went to my dads garage to clean the EGR valve (small holiday project I had planned), and it started just as bad as the other day (didn´t even fire up shortly as it used to, just cranking for ~10 seconds before it would slowly rise from the dead ).
I also noted that the squish sound didn´t appear any longer.
3 hours later when I was going to head home it would once again not start. Earlier on the car would pretty much start instantly, if it had been running within the last 12-24 hours. So it seems that the issue all of a sudden has worsened. When cranking the engine for extended periods of time it doesn´t seem to smoke or smell more than normal. Having a full tank or facing the front slightly downwards doesn´t either seem to change anything.
So where to go next? I guess it could be injectors seals (but then why would it recently start immediately after 5 days of standstill in a row)?
Lift pump (seems to work, as it pressurized the fuel system hard enough to shot off an unclamped fuel line when doing a diesel purge a couple of weeks ago). Or can a lift pump that is working still leak air?
I have a gut feeling, that the problems began after I replaced the fuel filter (Bosch), but I don´t have any proof supporting this. Should I just start off with replacing the fuel filter and thermo T?
Are there any non return valves in the fuel system on a PD that could go bad?
Every advice and suggestions will be very appreciated, as this cranking is making me cranky!
 
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LNXGUY

Top Post Dawg
Joined
Jan 10, 2004
Location
Barrie, Ont, Canada
TDI
'05 Jetta TDI Wagon
Could be the bad CPS (Crank Positioning Sensor). Are you getting RPM's on the tach when cranking? These tend to fail in the PD's quite commonly. you could also have a dying liftpump. On my '05 BEW (PD as well) starting got worse and worse until it wouldn't start at all. Or you could have a massive air leak like you mentioned :)
 

lindahl

Member
Joined
Dec 29, 2013
Location
Denmark
TDI
1,9 PD 101
Could be the bad CPS (Crank Positioning Sensor). Are you getting RPM's on the tach when cranking? These tend to fail in the PD's quite commonly. you could also have a dying liftpump. On my '05 BEW (PD as well) starting got worse and worse until it wouldn't start at all. Or you could have a massive air leak like you mentioned :)
Yes, I see rpm on the tach. I guess the lift pump would be a good place to start as it is rather cheap, and as I understand there are two non return valves on this that can go bad too. I just purchased the two o rings for the thermo tee. I will start with replacing the fuel filter and inspect the tee for cracks, and then use vaseline on the new o rings when I put it together again. I would also like to add a bit of clear fuel hose to keep an eye on air bubbles in the fuel lines. What sort is recommended on a tdi pd?
Would it be stupid to fit a non return valve on the return line, and if not are there any special requirements?
 

lindahl

Member
Joined
Dec 29, 2013
Location
Denmark
TDI
1,9 PD 101
So

After I took the car for a ride just around New Year, where I ensured that the engine reached full operational temperature, there has not been any starting problems, with the exception of one single morning, for the past 3 weeks, even though the temperature has been dropping. Then yesterday I got around to fitting another check valve (also a spring loaded type) to the return fuel line between the tandem pump and the thermo-T. I took it for a spin, and all felt good. Then this morning when the wife was going to work, it died and wouldn´t start again. Luckily she didn´t go far, so we switched cars and I tried to switch the ignition on and off several times before trying to start the car. After cranking 3-4 sek. it fired up, and I took it for a spin. Car ran fine. Then a 4 hours later I tried to start it again, fired up immidiately, but after a couple of minutes idling it starting to run rough in idle and hesitated some when I tried to rev it a bit. I shut it off, and tried to start it again but absolutely no luck in that. I then removed the check valve from the return line, as this was my prime trouble suspect. After having cranked the engine for 5-6 sec. it fired up, and idle seem better, but not perfect.
I´m going to take the car for a spin later this evening, just to see if there are any immediate problems, and will also scan it with vcds for any logged errors.

I´m still puzzled. When switching on ignition the lift pump is audible if you put your ear close to the rear seat. The tandem pump has been replaced with in the last 3 months, and last I checked the injectors and timing belt was well within spec.
 

coachgeo

Veteran Member
Joined
Mar 5, 2006
Location
Dayton OH area
TDI
99 Blue Bug.. new top end
Sorry maybe you mentioned it in the opening message and I missed it........ but when was last time you redid the timing? How far from time to change your timing belt are you?
 

30_Yr_Dsl_Veteran

banned Ric Woodruff alias account and troll
Joined
Dec 20, 2013
Location
Lake Placid, FL
TDI
2009 Jetta
Sorry maybe you mentioned it in the opening message and I missed it........ but when was last time you redid the timing? How far from time to change your timing belt are you?
If the timing was off, it would run badly and/or put out lots of black smoke. Is it, once you get it running? :confused:
 

lindahl

Member
Joined
Dec 29, 2013
Location
Denmark
TDI
1,9 PD 101
Sorry maybe you mentioned it in the opening message and I missed it........ but when was last time you redid the timing? How far from time to change your timing belt are you?
The timing belt was changed around 10.000 mile ago. The Torsion value says 0,8-1,0 at idle, so I think it is within recommended spec, although slightly to the high side.
 

lindahl

Member
Joined
Dec 29, 2013
Location
Denmark
TDI
1,9 PD 101
Intank liftpump working? Any other drivability issues once you actually get it running?
Not completely sure. If I put my ear close to the rear passenger seat it is audible for a short moment when ignition is switched on. When I installed the check valve on the feed line a couple of months ago it made enough pressure to make a huge squirt of diesel when I turn on the ignition with the line open.
It is the early design PD lift pump, so it should be able to run without the pump functioning I think. Can the lift work be the problem, when it is audible (not loud or anything) Would the next step be to verify that the fuel quantity from the lift pump is correct (dirty job)...

My wife uses the car for semi long commuting, so it is really annoying that she can´t rely on it :mad:
 

LNXGUY

Top Post Dawg
Joined
Jan 10, 2004
Location
Barrie, Ont, Canada
TDI
'05 Jetta TDI Wagon
The CPS is cheap, if you've exhausted all your other options you might wanna swap it.

Also, have you tried to clamp the fuels lines the night before? If you've got an air leak at the fuel filter, this is a simple test to verify if the thermostatic T is letting air into the system.
 

Redneck Truck

Gone, but not forgotten
Joined
May 3, 2009
Location
Plano, TX
TDI
2008 Touareg V10, 2001 Audi TTQ Roadster TDI 6-speed, 2005 Jetta Wagon TDI 6-speed
What are your fuel temperatures? I noticed a pattern with mine (possibly different problem) where the car starts fine when cold, but once the fuel temps are around 90°C, the engine won't restart without either a lot of cranking, or a few minutes of sitting. Along with this, after the engine is warm, it makes no power and stumbles/hunts for idle while coming to a stop.

I replaced the fuel and coolant temperature sensors to no avail (still high temps after running a while) and concluded that something is heating the fuel up - either the cylinder head is hot because of a bad camshaft, the tandem pump is hot, or the thermostatic tee is not properly recirculating fuel to the tank.

So, I've purchased the thermostatic tee ($12, can't go wrong), I've got a spare "known good" tandem pump, and I'm tackling the camshaft since it is showing visible wear and my balance numbers are far enough off from 0 that at least one cylinder is suspect.

I also plan to observe cam and crank position sensor outputs, as it is my suspicion that one of these has an intermittent failure and heat soak is what causes the symptom.

Good luck with your search, and please report back if you find a resolution!
 

coachgeo

Veteran Member
Joined
Mar 5, 2006
Location
Dayton OH area
TDI
99 Blue Bug.. new top end
What are your fuel temperatures? I noticed a pattern with mine (possibly different problem) where the car .... one of these has an intermittent failure and heat soak is what causes the symptom.
Redneck....... dont want to hijack this fella's thread so I'll be brief. Time it take for yours to develop issues could very well be heat BUTT....... it also could be a very tiny vacuum leak that takes time to build into a noticiable issue. Afterwords it takes time for air issue to get resolve enough by what ever built in bleed mechanism with in MK4's fuel system. Sorry don't know the MK4's design well but every diesel has a way some air automatically bleed out during running. Problems arise when this some is to large a volume for it to handle
 
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EXrider

Well-known member
Joined
Mar 31, 2008
Location
Lawrenceburg, IN
TDI
04 Jetta TDI GLS 5 Speed
What are your fuel temperatures? I noticed a pattern with mine (possibly different problem) where the car starts fine when cold, but once the fuel temps are around 90°C, the engine won't restart without either a lot of cranking, or a few minutes of sitting. Along with this, after the engine is warm, it makes no power and stumbles/hunts for idle while coming to a stop.
I replaced the fuel and coolant temperature sensors to no avail (still high temps after running a while) and concluded that something is heating the fuel up - either the cylinder head is hot because of a bad camshaft, the tandem pump is hot, or the thermostatic tee is not properly recirculating fuel to the tank.
So, I've purchased the thermostatic tee ($12, can't go wrong), I've got a spare "known good" tandem pump, and I'm tackling the camshaft since it is showing visible wear and my balance numbers are far enough off from 0 that at least one cylinder is suspect.
I also plan to observe cam and crank position sensor outputs, as it is my suspicion that one of these has an intermittent failure and heat soak is what causes the symptom.
Good luck with your search, and please report back if you find a resolution!
I've always had similar issues (though not nearly as pronounced) with my PD ever since I bought it with 130,000mi on the odometer. Starting takes a slightly longer crank when hot (always starts 1st crank though) and idle occasionally shudders when hot coming off of a highway jaunt at operating temp. I don't experience any no/low power issues though, I don't have any visible crank, lifter or follower wear and UOA's still look good at 230,000mi. The issues are actually less pronounced after I did the last TB change at 200,000, but still somewhat present. I have a new lift and tandem pump, tried replacing the t-stat T years ago, but the replacement leaked so I put the old one back in and rolled with that ever since.
 

LNXGUY

Top Post Dawg
Joined
Jan 10, 2004
Location
Barrie, Ont, Canada
TDI
'05 Jetta TDI Wagon
I've always had similar issues (though not nearly as pronounced) with my PD ever since I bought it with 130,000mi on the odometer. Starting takes a slightly longer crank when hot (always starts 1st crank though) and idle occasionally shudders when hot coming off of a highway jaunt at operating temp. I don't experience any no/low power issues though, I don't have any visible crank, lifter or follower wear and UOA's still look good at 230,000mi. The issues are actually less pronounced after I did the last TB change at 200,000, but still somewhat present. I have a new lift and tandem pump, tried replacing the t-stat T years ago, but the replacement leaked so I put the old one back in and rolled with that ever since.
CPS sensor, ecu grounding issue.. 04 cars seem to suffer from this, the 05+ cars don't. (I am referring to the grounding issue)
 

lindahl

Member
Joined
Dec 29, 2013
Location
Denmark
TDI
1,9 PD 101
The CPS is cheap, if you've exhausted all your other options you might wanna swap it.
Also, have you tried to clamp the fuels lines the night before? If you've got an air leak at the fuel filter, this is a simple test to verify if the thermostatic T is letting air into the system.
First of all thanks for all the replies - they are very appreciated :)

I haven´t tried the clamping procedure, but as I do have check valves installed in both the feed and the return line between the vacuum pump and fuel filter, I guess these should have the same effect!?!
A (intermitten) bad CPS would result in a error code, right? No errors when scanning with VCDS.
Again today the wife called and said that the car stumbled (died) while driving, and wouldn´t start. After having turned the ignition on/off several times and a fair amount of cranking it fired up, and transported her the rest of the way with out any other problems.
Both times it has stumpled/died while driving the car has been nearly dead cold and driving very low revs. She drives ½ mile to drop off the kids, and then continues on her 40 mile trip to work. Both times it died shortly after she left after dropping of the kids, and when she had to overtake a stopped bus, so she thinks she may have had it in the wrong (one too high) gear, resulting in very low revs.
Could a dying lift pump be a cause to this? (When switching on the ignition last night, as I had to inspect a failed bulb, it made the very distinct swooshing sound, so it isn´t entirely dead I think). The engine doesn´t seem to misfire.
 
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coachgeo

Veteran Member
Joined
Mar 5, 2006
Location
Dayton OH area
TDI
99 Blue Bug.. new top end
sounds like it sucks up some crud. Say in the tank? dies....... crud falls away. Scenario repeats as the crud finds its way around the tank and back by the pick up.

Has this happened after filling the tank from a place you normally do not get fuel? Bad diesel?

Also your add in check valves. did this start happening not long after installing them? Is something indiscriminately blocking one of them in a similar scenario to described above
 

lindahl

Member
Joined
Dec 29, 2013
Location
Denmark
TDI
1,9 PD 101
Just a short follow up. The car hasn´t died since my last post (hurrah), but the car still suffers from the occasional hard start, which is easily cured by applying the accelerator pedal just a little, and keeping it around 1300-1400 rpm for the first couple of seconds.
Haven´t got around to replacing the lift pump yet, but it´s still on the to do :eek:

But then yesterday, more by coincidence, I made an error scan of the car with VCDS, and I got the following error:

Address 01: Engine Labels: 038-906-019-AXR.lbl
Part No: 038 906 019 AF
Component: 1,9l R4 EDC G000SG 1110
Coding: 00002
Shop #: WSC 13765
VCID: 5BBFE6C8E43C
TMBGS26Y123388942 SKZ7Z0A1118225

1 Fault Found:
16688 - Cylinder 4: Misfire Detected
P0304 - 35-10 - - - Intermittent
Readiness: 0 0 X X X

I took the car for a short spin, and made a log of measuring block 13, where I could see that at idle cylinder 1 + 2 got values around +/- 0.75, while cylinder 3 + 4 got values very close to 0. Under certain driving conditions the values for cylinder 1 + 2 would increase all the way up to +/- 2.1, while cylinder 3 + 4 would reach around +/- 0.7.

I have noticed that the car suffers somewhat from low rpm (<1.500) judder in high gear (3.-4.-5.). This haven´t really bothered me alot, as it could be cured with a quick downshift. But after having borrowed my parents car one night, which has a sligthly newer version of 1.9 TDI, I found that this had very smooth acceleration down below 1.500 rpm too.

Could a bad lift pump result in crappy injector values (my logic tells me that all injectors should be affected then) and judder at low rpm?

I guess I´ll try and have a look at the camshaft and lifters, and if these turns out to be okay, I guees I´ll try to replace the injector loom if the lift pump doesn´t cure the judder.

Just don´t hope it´s one or more bad injectors... :(
 

BobnOH

not-a-mechanic
Joined
May 29, 2004
Location
central Ohio
TDI
New Beetle 2003 manual
........
Pumps are easy to diagnose. Remove any of the lines from between the tank to the 'IN' line for the tandem pump. Fuel will come out for a few seconds when you turn the key. We remove the line at the tandem pump and cycle the key until we get fuel.
This test, also if the car ever sits very long, you might check for algae (black slime) or other crd it the tank
 

lindahl

Member
Joined
Dec 29, 2013
Location
Denmark
TDI
1,9 PD 101
On PD's? Not likely..

OP did you test the liftpump?

Also, once you cleared that misfire code does it come back? If so, it's most likely a bad injector harness (Common problem on PDs)... The injectors rarely if ever go back on these cars.
No, I was at a point where I just thought to hell with it, and order a new pump. Replacing a pump that has 250.000 miles on it wouldn't hurt anyway - just never got around to it :eek:

I made a scan today after the wife returned from work, and no misfires had been stored. I suspect the misfire(s) may have something to do with the couple of times where the car has died while the wife was driving it.
I'll try and make a scan next time it happens, to see if the fault returns.
 

LNXGUY

Top Post Dawg
Joined
Jan 10, 2004
Location
Barrie, Ont, Canada
TDI
'05 Jetta TDI Wagon
Gotcha. And yeah, never a bad idea to replace a liftpump with 250,000 miles on it.. Sooner or later, you know it's going to die :)
 

lindahl

Member
Joined
Dec 29, 2013
Location
Denmark
TDI
1,9 PD 101
Just a quick follow up: Replaced the intank pump about a month ago and the hard starts seems to have gone away for now. I also noticed that the "swoosh"-sound, that I would encounter when turning the ignition on has more or less vanquished.
At the moment I'm full of hope
 

vince espinosa

New member
Joined
Jul 20, 2018
Location
washington state
TDI
2006 jetta
2006 jetta tdi with 234,000 miles, drives 150+ miles a day.

I've always had similar issues (though not nearly as pronounced) with my PD ever since I bought it with 130,000mi on the odometer. Starting takes a slightly longer crank when hot (always starts 1st crank though) and idle occasionally shudders when hot coming off of a highway jaunt at operating temp. I don't experience any no/low power issues though, I don't have any visible crank, lifter or follower wear and UOA's still look good at 230,000mi. The issues are actually less pronounced after I did the last TB change at 200,000, but still somewhat present. I have a new lift and tandem pump, tried replacing the t-stat T years ago, but the replacement leaked so I put the old one back in and rolled with that ever since.

I have a 2006 jetta tdi with 234,000 which I put 55,000 miles in exactly two years, new head assembly was replaced including new cams drives like brand new until a month ago, starting to have hard start issue, replaced the battery fixed that for a while..issue came back.. getting harder and harder until it just cranks and no start..yesterday, I finally replaced tandem pump, still would not start, just crank... sucked fuel out of return line from tandem pump, saw air pockets thru clear hose line then started reluctantly. I drove the car for 33 miles, came home and shut down for the day. This morning, temp around 60 degrees..engine reluctantly started.. at least it started..

Before I proceeded to replaced tandem pump yesterday, I checked for lift pump sound with seat off, I heard it but kinda faint sound! not like my previous Mitsu Lancer which is more audible.
Is this a good indicator that lift pump is now the problem?
 

vince espinosa

New member
Joined
Jul 20, 2018
Location
washington state
TDI
2006 jetta
I have a 2006 jetta tdi with 234,000 which I put 55,000 miles in exactly two years, new head assembly was replaced including new cams drives like brand new until a month ago, starting to have hard start issue, replaced the battery fixed that for a while..issue came back.. getting harder and harder until it just cranks and no start..yesterday, I finally replaced tandem pump, still would not start, just crank... sucked fuel out of return line from tandem pump, saw air pockets thru clear hose line then started reluctantly. I drove the car for 33 miles, came home and shut down for the day. This morning, temp around 60 degrees..engine reluctantly started.. at least it started..

Before I proceeded to replaced tandem pump yesterday, I checked for lift pump sound with seat off, I heard it but kinda faint sound! not like my previous Mitsu Lancer which is more audible.
Is this a good indicator that lift pump is now the problem?
 
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