Loss of Prime or Something Else?

Austin01

Member
Joined
Mar 25, 2017
Location
IL
TDI
2000 Jetta
Hello All,

I have been reading around for the answer to my problem and seem to have pinpointed it but want to get the more professional opinions before I pull the trigger on purchasing ANOTHER part!

He is the synopsis; I have a 2000 VW Jetta ALH Automatic, I just had the head rebuilt, put a new VNT 15 on it, performed a full timing belt job, installed a new radiator, oil cooler, rebuilt injectors with new nozzels, replaced the battery with a more beefy 900 CCA one and installed an EGR delete. I checked the timing after installing the new timing belt and the timing is just slightly advanced.

The car starts like a dream majority of the time. I have recently been encountering an occasional hard start problem. It can be cold or warm and it doesnt make a difference. Prior to performing all the work listed above I could not get the car to turn over so I pushed it into the garage and began all the work listed above prior to installing the new battery. At that point it was a cold day and I figured something of the massive amount of work I was about to do would fix it. That was my first encounter of the problem. I performed all the work and it fired right up no issues. Drove it for roughly 300 miles with the remaining fuel in the tank before filling it up. Went out to start it one cold morning and it would just crank, no start but sounded like a slow crank. Figured maybe the fuel was bad since I had just filled up the tank the prior day so i threw in some diesel 911 filter and tank. No help. Tried a shot of starter spray and a jump and it fired up after a little bit of a crank. So I replaced the battery. Had been starting like a dream. Today I came out from work cranked no start. Tried a couple times with no luck. Finally I decided to just let her crank in hopes eventually it would turn over prior to draining the battery since it is such a new battery. After a long crank it slowly sputtered to life. Today it is warmer out (about 27F) rather than the 16F it was last time I had the issue. Prior to all the work performed above I had just installed a newly rebuilt alternator. The previous owner had already had a new glow plug harness and plugs installed about 10,000 miles ago he had also replaced the starter about 4 years ago when the last time was he replaced the battery. It has a newer crank position sensor and speed sensors as well as the newer gray 109 relay.

The times the car just cranks the glow plug light comes on as normal and stays for quite a few seconds as normal before turning off and me attempting to turn the car over.

With all this said, I am thinking about throwing a lift pump in the tank in hopes of this solving the problem but wanted to get opinions on it before throwing close to another $400 bucks at the car. It has 300,000 miles on it but I was hoping to have a reliable ALH in the end... Does all of my ranting sound like a loss of prime issue or is there somthing else I should be looking at or taking into consideration. Additionally, I started it this morning in 2F no issues, glow plug light came on turned off cranked and instantly fired right up. So why in the afternoon would it take a roughly 15 second crank to sputter to life?! Once getting home I looked at the clear line from the fuel filter and there was no signs of bubbles while the car was running.

I should mention the previous owner had taken it to the dealer roughly 6 years ago for a new injector pump. So I am hoping to safely rule that out of the question as there appears to be no sign of leaks around the pump at all and is not making any noises. Additionally the car is throwing no codes other than the ones from the EGR delete.

Any help is appreciated! Thank you in advance!
 

KLXD

Top Post Dawg
Joined
Aug 22, 2009
Location
Lompoc, CA
TDI
'98, '2 Jettas
Sounds like loosing prime is the first thing to look at.

Have you checked the filter tee, fuel lines, etc?

An electric pump isn't the fix for a leak.
 

RallySport

Well-known member
Joined
Apr 5, 2017
Location
Washington Twp, MI
TDI
2002 Golf TDI ALH
About 2 months ago i had to get my I/P resealed as it lost its prime(and wouldnt prime period). After it got resealed my crank, no start condition went away.

Replace the fuel return valve(tee fitting) at your fuel filter to eliminate this as being a possible point of entry for unwanted air... Its only like 2 bucks..

Also, have you tried pulling fuel through the injection pump at all with a mightyvac?

If you're getting fuel through the injection pump- crack 2 of the injector lines at a time and crank until you see fuel AND AIR bleed out of the injector lines. Repeat this as necessary to get the air out of the lines, its easy with the help of someone else in the car, just make sure you have ssafety glasses on and some towels.

Let us know
 

Austin01

Member
Joined
Mar 25, 2017
Location
IL
TDI
2000 Jetta
The fuel filter is rather new within about the last 5000 miles but I'll try a tee first. Not sure the best way to go about looking for leaking fuel lines as they in the frame it seems on the passenger side. Also I was reading last night of some people using the Mitty vac to test the system. I am still a little unclear at what exactly I am testing when I do that. I saw I should try connecting it to the return on the IP and if it will not suck fuel through its likely the pump seals?

Additionally worst case it is seals, is that something I can do myself or its just best to send it out?

Thank you all for the help!
 

jokila

Vendor
Joined
Dec 3, 2004
Location
Houston, Texas
TDI
2003 Jetta GLS, Manual
The fuel filter is rather new within about the last 5000 miles but I'll try a tee first. Not sure the best way to go about looking for leaking fuel lines as they in the frame it seems on the passenger side. Also I was reading last night of some people using the Mitty vac to test the system. I am still a little unclear at what exactly I am testing when I do that. I saw I should try connecting it to the return on the IP and if it will not suck fuel through its likely the pump seals?
Additionally worst case it is seals, is that something I can do myself or its just best to send it out?
Thank you all for the help!
When the seals are partially bad it can cause you to not be able to pull fuel through BECAUSE there is air entering the fuel system (lines and/or pump) in some way that keeps the miteyvac from maintaining a vacuum pulling of the fuel. The seals can act temperamental at times because they will hold but release and then your lose the prime in the pump.

My theory is the heat of the pump keeps the marginal seals working and as it cools down the seals can let air in, fuel siphons back to the tank and you have a no start condition. Once you start getting these symptoms of priming/losing prime it's only a matter of time before they give up the ghost and will need a seal change out.

The kit is cheap from idparts.com. There are about eight Youtube videos made by runonbeer from this forum that shows you everything you need to do it correctly. If you are person who doesn't follow directions exactly, or likes to improvise without understanding fully what the implications are, or perhaps weak with turning wrenches, then don't do it. You can ruin a critical part of the engine. However, the videos show you everything and it is very doable.

You likely will need to enlist the aid of someone with a VCDS for final tuning, but it's not 100% needed to get it running.
 

Austin01

Member
Joined
Mar 25, 2017
Location
IL
TDI
2000 Jetta
I appreciate you guys help. Do any of you have a good website as to where you get the Bosch Viton Seal kit? In looking around it seems most kits are not Viton...
 

UhOh

Top Post Dawg
Joined
Dec 24, 2014
Location
PNW
TDI
2000 & 2003 Golf GLS (2005 Mercedes E320 CDI)
Lots going on here, so kind of hard to really trace the problem...

BEFORE you did all this work how did the car start?

Can you elaborate on this:

I had just filled up the tank the prior day so i threw in some diesel 911 filter and tank

New filter?

I'd go for the low-hanging fruit first. Check Themo-T, maybe temporarily bypass or replace. One could first look to try resealing it.

Do you have a clear input fuel line (to IP)? Bubbles?

What happens when you crank w/cracked open injector line(s)? Strong fuel flow?

Look for ANY signs of fuel leaking. If you're not seeing any I'd think that any IP issues wouldn't be, yet, sufficient enough to be the only source of problems here.

Slow cranking with a new, 900 CCA battery? (not likely ASV) Check battery cables, grounds. 109 relay?

Are you sure of the static timing? I don't think that things would be partially erratic if the cam is off.
 

Genesis

Top Post Dawg
Joined
Feb 26, 2003
Location
Sevier County TN
TDI
'03 Jetta Wagon
Check and (probably necessary) fix the leak first.

My ALH, which does NOT have any sort of lift pump in the tank, has NO air bubble in the clear line after being shut down. It has no air leaks in the fuel system. It is not at all impossible to get an ALH to have a "tight and clean" fuel system without air leaks, but it may take some effort. The good news is that it usually doesn't take much money -- just time and effort.

(Note that one of the places you need to check -- closely -- is the *return* lines from the injectors, the thermal T, etc. Since that "T" is there and goes back into the fuel filter if you have air getting into the return side it can easily wind up in the FEED side of the pump -- and cause starting problems. The T itself -- due to either poorly-sealing O-rings or hidden cracks -- is known to be a somewhat-notorious cause of said trouble.)
 

Austin01

Member
Joined
Mar 25, 2017
Location
IL
TDI
2000 Jetta
Uhoh:

Prior to starting all the work it started great, never had a problem. If it makes any difference, it was this past summer when I bought the car from a private seller and therefore this is my first winter with it. All the way up until literally the day I was going to pull it into the garage to start all the top end work, it started fine. It had sat for about a week prior to me then attempting to start it to pull it in the garage to start the work that I then experienced it not wanting to start. It was a cold day and like I said, had been sitting so with the slow crank on the battery I figured that might just be the issue or maybe something with the fuel. Therefore I proceeded to just push the car into the garage and begin all the head work without trying to diagnose that problem much since it had never done the no start thing before.

When I put the diesel 911 in the car, I put some in the tank and the fuel filter separate as per the directions. I did not put a new filter on as the previous owner had it changed before I bought the car as I have a whole book of all his receipts and service records. The new filter he put in was done roughly 5,000 miles ago. This time when it did not start I put a Mitty Vac on the fuel line and was able to pump a nice stream of fuel in. I also cracked the lines on the tops of two injectors and cranked till fuel came out, and then did it to the other two. Tried cranking and still would not catch. Since I had not replaced the battery I tried jump starting it and even though it cranked faster, it still would not start. It was the time I put the forbidden shot of starter fluid in it and jumped it that it caught.

After the second time it occurred is when I put the new battery in that is 900 CCA. I had the previous battery tested at batteries plus and even though it was rated at 640 CCA it was only producing 500 something when tested. It had been starting like a dream just as it had been before I even had the issue. It starts perfectly fine anytime the issue does not occur. One short crank everytime and it fires up. A little white smoke typically on the cold start as expected in the cold but thats it.

The time between the 2nd time the car did it and this most recent time the car did it was about 2 weeks.

Today I ordered up a Fuel Tee and will hope that it is that simple of a fix. As i have tried checking the fuel lines for cracks but with them running in the frame for some of the way I cant physically see the lines.

I do have a clear input fuel line and see no sign of bubbles. I have been checking occasionally when it is running for any sign of bubbles but see none.

Fuel flow seems to be strong with cracked open injectors. The time I had done that when I put the diesel 911 in the fuel system, it would soak the paper towel I had wrapped around it.

I see no signs of leaking fuel on the injector pump. Went out again last night to check and I see and feel no signs of fuel. The pump is still pretty clean with no dirt and grime sticking to it in any of the areas where it might be leaking from a seal.

Sorry for the confusion, the slow cranking was with the old battery that was rated at 640 CCA and tested at 500 some CCA.

I have not tested the 109 relay as it is the new gray 109 relay and the glowplug light is coming on and staying on for sometime when the engine is cold. I had read that if it was a 109 issue that the glowplug light will not display? Additionally, I have no check engine light on for anything but the N18 valve that is non existent with the EGR delete.

I used the timing graph to check the timing and it is slightly above the center line when warm.

Like I said, I ordered the fuel tee off IdParts and will report back should the problem occur/not occur again.

It seems the fuel sending unit in the tank should not cause an issue like this unless the check valve is plugged correct? If you all have any other suggestions of tests I can perform I am more than happy to give them a shot as I have VCDS.

Thank you again!
 

burn_your_money

Veteran Member
Joined
Oct 16, 2012
Location
Missouri
TDI
99 Beetle, 96 B4V, 05 Passat wagon
To me it sounds more like a cranking issue than fuel. Do a voltage drop test on all the starter cables and see where that leaves you. You could also try starting with the car hooked up to booster cables or a charger on a high amp setting to see if that makes any difference.
 

maxmoo

Veteran Member
Joined
Jan 19, 2011
Location
Lakefield, Ontario, Canada
TDI
2000 golf, 2001 golf, 2000 beetle, 2003 wagon, 2004 golf, 2004 jetta, all diesels
Are you 100% sure that your glow plugs are really working?
Just because the plugs test good and your gp light comes on that still does not necessarily mean the plugs are glowing.
 

UhOh

Top Post Dawg
Joined
Dec 24, 2014
Location
PNW
TDI
2000 & 2003 Golf GLS (2005 Mercedes E320 CDI)
Austin, thank you for that last post, it was a great example of how folks should provide a comprehensive picture of what has happened.

I'm wondering whether the injectors are just crappy. Have fuel. Timing is OK. Everything had been operating fine (and no notes of any "events"). As maxmoo mentioned, it's a good idea to rule out the GPs: I'm figuring it's pretty cold there. You mentioned your pulled the car in to your garage; is the garage heated? If it's heated then GPs are probably not the issue: your car is warm enough.

Not having any air in the clear part of the fuel line would tend to suggest that air incursion is not the problem (thermo-T probably not going to do much).

What's the cranking speed like? A slow starter speed will be problematic: this is a start issue, not a battery issue. Check to see what kind of voltage drop you're getting when you crank. And... now that you have that new battery, how well is it holding up when cranking? If it's being drained down fast then this might be telling of a struggling starter (or connections).

Reports on what's happening at the tailpipe are helpful. Smoke (color)? Smell (raw fuel)?

This might come down to a compression issue. If you can get the car running and warmed up you might want to look at injector deviation (Group 013) as injectors will be commanded to vary fueling to make up for imbalances in compression between cylinders. It's just a kind of quick and cheap way to see if there might be a problem. An actual compression test is far more telling.
 

Austin01

Member
Joined
Mar 25, 2017
Location
IL
TDI
2000 Jetta
Well all, here is where it stands:

I put the new Fuel Tee on last night, car fired up good yesterday after putting in the Tee and fired up great this morning. I came out from work this afternoon and had another long crank to a sputtering start. Today it is about 40F so not all that cold... Yesterday when I had the Tee off, I unplugged the fuel lines from the sending unit and plugged them with a rubber end and put a mitty vac on both lines under the hood before they go into the fuel filter. Both lines held a vacuum so I am hoping to rule out any leak in the fuel lines.

As I said before they are rebuilt injectors with new Bosio DLC 520 nozzles. I purchased the upgraded complete injectors from IDparts. It sounds like they send them to Bosch to have the new nozzles mounted and calibrated. So I dont think those would be an issue. My Measuring block 013 numbers are as follows:

1) 0.45
2) -0.87
3) 0.24
4) 0.12

I rechecked the timing on the graph and it is just above the blue line right about 110 and 50.

I had ohm tested the glow plugs the first time this happened and they all checked out at 1 ohm a piece. Any other ideas to test these?

I have not had a chance to do the voltage drop test as I am hoping the problem will occur again sometime when the car is at home so I can run those tests on it.


I am thinking once I rule everything out electrically that it could be, I will order up injection pump seals as a last resort.
 

UhOh

Top Post Dawg
Joined
Dec 24, 2014
Location
PNW
TDI
2000 & 2003 Golf GLS (2005 Mercedes E320 CDI)
OK, so injectors are probably fine.

The IP was replaced six years ago doesn't necessarily rule IT out. Leaking IPs will leak IN air well before you see signs of fuel leaking OUT: and it's air entering that's the problem. As your car is an automatic I don't believe it has a clear section of fuel line to the IP: still don't know why VW did this! This makes it hard to determine if you are getting air in the fuel system. Really, this seems like that's what's happening here.

Perhaps disconnect the input fuel line, tack on a clear section of line and then drop it into a separate bottle of fuel (or diesel purge). Don't believe that you need to run the return lines to this separate bottle: others can say whether it would be a good idea- note, however, that bad fuel return lines can also be problematic, can pull in air, though this seems less of a problem than from the fuel filter to the IP. If after sitting a while you see air in the [clear] fuel line then the IP is sucking in air.

Has there been a scan? How's the MAF? (maybe unplug it and see if that makes a difference when it's being nasty)
 

Austin01

Member
Joined
Mar 25, 2017
Location
IL
TDI
2000 Jetta
Alright, the injector pump seals came in and I finally had time to put them in the other day. I ordered the Viton head pump seal from DieselGeek as well as the Bosch seal kit from them. I replaced the three seals most people suggested and we will see what happens!

It was a good opportunity to cut the fueling back a little bit with the slightly bigger injectors I had put in. Bumped the IQ up to around 5.

I will keep you all posted as to whether the seals solved the issue!

Thank you for all the responses!
 

UhOh

Top Post Dawg
Joined
Dec 24, 2014
Location
PNW
TDI
2000 & 2003 Golf GLS (2005 Mercedes E320 CDI)
Fingers crossed!
 

Austin01

Member
Joined
Mar 25, 2017
Location
IL
TDI
2000 Jetta
Well, it has been a couple weeks since I replaced the IP seals and I have not had the problem re-occur! So I am thinking the new IP seals did the trick!

Thank you for everyone's help and advice!
 

jmodge

Top Post Dawg
Joined
Jun 18, 2015
Location
Greenville, MI
TDI
2001 alh Jetta, RC2 w/.205's 5speed daily summer commuter and 2000 alh Jetta 5spd swap, 2" lift, hitch, stage 3 TDtuning w/.216's winter cruiser, 1996 Tacoma ALh
Are you 100% sure that your glow plugs are really working?
Just because the plugs test good and your gp light comes on that still does not necessarily mean the plugs are glowing.
You mentioned starting fluid? Glow plugs could ignite that, maybe they don't work. We cycle our glow plugs 3 times and it makes a difference on cold starts. Can you put it in a heated garage to see if it makes a difference? just thinking simple to start with here.
 

jmodge

Top Post Dawg
Joined
Jun 18, 2015
Location
Greenville, MI
TDI
2001 alh Jetta, RC2 w/.205's 5speed daily summer commuter and 2000 alh Jetta 5spd swap, 2" lift, hitch, stage 3 TDtuning w/.216's winter cruiser, 1996 Tacoma ALh
oops! missed post #19
 

Austin01

Member
Joined
Mar 25, 2017
Location
IL
TDI
2000 Jetta
Well here we are a winter later and the problem I thought I had fixed is back. I had a couple long cranks in which I got it started but most recently the other day she cranked and would not start. Cracked the injectors and got her goin. So the problem is for sure air in the system but I need suggestions on what to look at or how to rule things out. Last winter I did the injector pump seals except the main one as I do not see any leaks or drips around the pump. I also had bought a new T last year as well. This issue only happens when it gets cold and even then is not consistent in when it has long cranks or may not start at all. I can come out on a morning after a super cold snap and it fires right up. Other times, she gives me a long crank and sputters to a start.

Is there an aftermarket fuel filter any one suggests to get rid of the T?

I have yet to replace the lines between filter and pump.

Any and all suggestions welcome!

Thanks!
 

JB05

Top Post Dawg
Joined
Oct 20, 2005
Location
Il.USA
TDI
Golf,2005,anthracite blue
I wonder if the sending unit inside the tank could cause be a factor from gelled fuel. A plugged check valve perhaps.
 

Brett San Diego

Veteran Member
Joined
Jun 25, 2013
Location
San Diego
TDI
02 Jetta wagon manual
... Last winter I did the injector pump seals except the main one as I do not see any leaks or drips around the pump. ...

Any and all suggestions welcome!

Thanks!
Um, how about considering the pump head O-ring that you ignored? I presume that's the "main one" you're referring to.

You have exactly the symptoms mine had. Occasional random hard start that seemed worse on colder days. Then, one day, it simply wouldn't start at all. I checked everything I could find on the forum regarding a no-start condition and everything checked out OK. I settled on the IP seals and replaced them, 2 quantity adjuster seals and the pump head O-ring. And, my pump never showed any external leaks. My experience is findable on the forum with a little searching.

That was 5 years and 120,000 miles ago. No issues since.

Brett
 
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