car turns over but won't start after sitting for 4 hrs

Scenario:

Driving back from Nova Scotia. My 1997 1z TDI Jetta decided to have some issues. I pulled into a parking area to rest my eyes for a few hours. After 4 hours, I turned the ignition and the car cranked like it would start but didn't. It was cranking pretty fast. Started was cranking the engine, engine was turning over.

I was able to jump start the car. It got me back to Toronto. 10 hour drive. I even stopped for lunch for an hour. The car started up like normal. Problem with no start seems to happen when car is sitting for 3-4 hours or longer.

Note:
While driving on the hwy on the way back, car would feel like it was going into limp mode. As soon as i hit 120, it would not accelerate. I would coast until speed was at 80km and then i could accelerate again.

Things i've tested and tried:

relay 109=working, swapped with 2 working spares
timing belt checked=not broken, missing teeth etc:
all drive belts good
I.P not leaking
Battery voltage good
fuel is getting to injectors, squirts pretty high
battery connections are clean and tight
ground points are clean and tight
starter/alternator connections clean and tight
fuel shutoff tested=working
I was able to jump start the car and make the drive back to Toronto, which was around a 10 hour drive.

When i arrived in Toronto, i swapped the starter with a used one from a wrecking yard. Exhibited same no start issue.

If anyone has any tips, please advise. I'm totally stumped right now.

Thanks

It sounds like it maybe getting air in the fuel line. Look for a slight leak.

Joe_Meehan said:

It sounds like it maybe getting air in the fuel line. Look for a slight leak.

Click to expand...

Hi, I rechecked for leaks, still dry. Could a faulty coolant sensor create a problem like mine?

edit: I also used an alternate fuel source when i was stuck in Quebec. I ran power service straight to the I.P from a bottle. I was trying to see if it was bad fuel. This was all before i jumped start the car.


thanks

problem almost solved....

small update....

After reading numerous articles and going back to the original tdi faq. I unplugged the engine coolant sensor harness. Cranked over the car and it started within a few seconds. It was smoking but running (a tad rough). I've ordered the sensor (2 actually). I'll keep one as a spare. After i install it, i'll test/check the car and post what i find.

Seems like this sensor was my problem. If so it's an inexpensive part and will allow me to drive again.

I now have a spare Starter motor that works good. I plan on getting a spare alternator too. For future road trips.

close maybe, but no cigar.....

update.....

Installed new coolant sensor, still same problem. Car would not start with sensor connected to harness. I unplugged the harness and car started up right away. So i'm stumped once again.....

Note: i let the car run for about 5 min with sensor connected. I then turned the car off and restarted. It started up right away. So it seems when the engine is cold and the sensor is connected. The car won't start and run.

The only other thing i can think of is that maybe might foot might have kicked some wire or something under the dash/fuse area. When i was stretching out to rest my eyes. I've checked the fuses and glanced at the wires. Everything seemed good.

Timing

I see you have adjusted your timing according to your profile. Consider the timing & temperature are related. Maybe you should check your timing with new CTS installed.

2004STARWARSTDI said:

I see you have adjusted your timing according to your profile. Consider the timing & temperature are related. Maybe you should check your timing with new CTS installed.

Click to expand...

Looks like i'll have to get a VAG scan to get the timing checked. I was hoping i didn't have to.


So far i've based all my diagnostics on a multi-meter, test light and SG2. I don't have any codes on the SG2. When i unplugged the ECT sensor. The code 1256 popped up. I cleared it.

I'm trying to explain as best as i can. I hope i'm not confusing anyone, cause i'm starting to get confused. After checking everything i can find. I'm still stumped.

bump.....for any other ideas....while i wait to get a scan on the vehicle....

One possibility is the shaft seal on the injection pump. When shut down, the pump body goes to a slight vacuum and seal can introduce air. Fuel then drains back to the tank. No external fuel leak there. Once running, fuel pressure causes the seal lip to seal to shaft. Again no external fuel leak.

On one ve pump engine, I put an outboard squeeze bulb on the inlet to the fuel filter. If engine would not start, I would sqeeze it a few times and then it would start, although sluggishly. I eventually put a new shaft seal in (pump installed, its do-able) and never had the problem again.

If cranking and it is not starting, is white smoke coming out tailpipe? If not, no fuel is being injected.

You can also put a clear fuel liine on the injection pump discharge (return line). If when it does not start there is air in that line, you've got an air leak.

Ski in NC said:

One possibility is the shaft seal on the injection pump. When shut down, the pump body goes to a slight vacuum and seal can introduce air. Fuel then drains back to the tank. No external fuel leak there. Once running, fuel pressure causes the seal lip to seal to shaft. Again no external fuel leak.

On one ve pump engine, I put an outboard squeeze bulb on the inlet to the fuel filter. If engine would not start, I would sqeeze it a few times and then it would start, although sluggishly. I eventually put a new shaft seal in (pump installed, its do-able) and never had the problem again.

If cranking and it is not starting, is white smoke coming out tailpipe? If not, no fuel is being injected.

You can also put a clear fuel liine on the injection pump discharge (return line). If when it does not start there is air in that line, you've got an air leak.

Click to expand...

Thanks for the reply. That's a great tip for the shaft seal.

I've been getting fuel for whole duration of this problem. I think i dismissed the fuel issue when i got stuck on the road in Quebec. I first checked the injector lines and then roll started the car. It cranked over and ran for 10 hrs on the drive home.

With the ECT disconnected, car starts on first try and runs a bit rough. I've driven it lately, it seems to cut out and restart itself while driving at different speeds on the roads. It doesn't stall out completely, where i would have to turn the ignition again. It also lacks power.

With ECT connected, car cranks(engine turns over at a fast rate) but does not start. Lots of white smoke comes out of the exhaust (rear tailpipe) and from the flex leak i have (which seems to be getting bigger).

While the car was running i checked the N75 which i replaced last year. It's still clean and ticking away at a fast rate.

Anyone know what the glow plug relay number is? Is it 167. I went to VW today to see what it cost. I almost fell over when i heard about the price for this little plastic relay. CAD $177.00. It seems that the relay i have in the car is an aftermarket. I'm not sure how to test it yet. I'll need some instructions for that.

So far, what i know is that the glow plug circuit is getting voltage, the glow plug ohm test is good. However, when i turn the ignition to power the glow plug system. The light comes on and goes out real fast. It's really warm here, over 9*C. I don't hear any relay clicking. The other thing i know is that by disconnecting the ECT. The glow plugs stay on for 20 seconds and the engine fires right up. So it seems that the glow plugs are not staying on long enough with the ECT connected to get the engine started.

There is a relay under the hood area with high voltage fuse. This i've read is for the aux glow plugs that are used to heat the coolant. Is this relay tied into the main glow plug circuit. I don't hear it making any noise or anything when i power on the car.

Another thing that i see happening is. After i get the engine started and running. It drives like crap and sometimes idles rough.

I'm going to check the fuel sending unit check valve tomorrow. I don't really get this problem. One minute it's driving excellent and the next it won't start. I've read so many no start threads and low power threads trying to get tips and stuff.

That is where i'm at right now.

Forget about the shaft seal at this point.

If you cheat the glow plugs into turning on, and then it starts, sounds like late injection timing.

Normally, tdi's require NO glow plug to start unless down to a few degrees C.

I'm thinking late timing, which could be a loose crank bolt/sprocket. Sprocket runs loose and wears on crank and timing slips.

Check crank pulley center bolt for tightness. If loose, you found it.

Ski in NC said:

Forget about the shaft seal at this point.

If you cheat the glow plugs into turning on, and then it starts, sounds like late injection timing.

Normally, tdi's require NO glow plug to start unless down to a few degrees C.

I'm thinking late timing, which could be a loose crank bolt/sprocket. Sprocket runs loose and wears on crank and timing slips.

Check crank pulley center bolt for tightness. If loose, you found it.

Click to expand...

Thanks again for the reply. I'll check that bolt. I noticed that while the engine is running. It's a bit wobbly around that pulley section. I thought it was normal. I think it's been like that since i purchased the car last year. I've read that the AAZ engine had a problem with this, but the 1Z didn't.

From what I've read, the AAZ was worse about the crank snout problem. 1Z is better. ALH got it solved.

If the bolt is loose, DO NOT TIGHTEN IT. It is a one time use / torque to yield bolt.

I would make preparations ASAP to replace the timing belt, crank seal, and new bolt. BTW...replacing the crank seal is a PITA. I'll let you do some searching...interesting reading.

Tony

TonyJetta said:

From what I've read, the AAZ was worse about the crank snout problem. 1Z is better. ALH got it solved.

If the bolt is loose, DO NOT TIGHTEN IT. It is a one time use / torque to yield bolt.

I would make preparations ASAP to replace the timing belt, crank seal, and new bolt. BTW...replacing the crank seal is a PITA. I'll let you do some searching...interesting reading.

Tony

Click to expand...

It's been pouring here all day. I disconnected the ECT, started the car and took a look at the crank pulley. It has a slight wobble, just like when it did when i first got the car. I tried wiggling the crank pulley and it seemed solid. I didn't make it to the bolt yet as it was too soaked to crawl under the car. Is it safe to say that if the pulley is not loose, wobbling like crazy the bolt might still be ok?

edit....forgot to mention that i took another look at the Timing Belt. All the teeth as far as i can see are intact. The belt is very snug, no major play detected. I also cleaned out the soot from the glow plugs, still no go.

What i might know now........ By unplugging the ECT, the glow plug time is extended to 20 seconds. Does unplugging this sensor also advance the timing?. After i wait the 20 seconds, the car starts up right away but drives like crap.

honda_vtec2 said:

What i might know now........ By unplugging the ECT, the glow plug time is extended to 20 seconds. Does unplugging this sensor also advance the timing?. After i wait the 20 seconds, the car starts up right away but drives like crap.

Click to expand...

That seems to indicate timing is retarded. Think of the injection pump like a distributer in a gas engine; it controls when combustion occurs. Only the IP is MUCH more complex.

Does it drive better when warmed up?

Do you have VCDS (was vag-com)? There's a sticky at the top of TDI101, 'VAG_COM LOCATER', if you don't have access to one.

Tony

TonyJetta said:

That seems to indicate timing is retarded. Think of the injection pump like a distributer in a gas engine; it controls when combustion occurs. Only the IP is MUCH more complex.

Does it drive better when warmed up?

Do you have VCDS (was vag-com)? There's a sticky at the top of TDI101, 'VAG_COM LOCATER', if you don't have access to one.

Tony

Click to expand...

Thanks for the reply tony.

That was the answer i was kind of hoping to hear. How does the timing go retarded?. I had it advanced 3 degrees last year via adaptation. The static timing was set right in the middle of the graph in basic settings and then adapted via software to +3 degrees. I haven't touched or changed anything since. I don't see the timing belt stretching or loose either. So that kind of puzzles me.

The vehicle when warm has a smooth idle of 903-905 rpms. Driving it around it seems to stumble at all speeds from time to time. Like it is going to stall out, but never does. When it loses power, i step on the gas, but engine does not rev up. After 5-10 seconds, it re-gains power. I've driven it with the MAF disconnected and connected, same symptom. I've also tested this with the EGR connected/disconnected.

I don't have VAG yet. I've msg'd a current member who is an expert with the TDI and lives close to me. If he has some time, i'll be able to pin point where the issue is.

Do you see a lot of air in the fuel lines?

I know Passat's are prone to this: There is a check valve in the fuel tank pickup assy that can get clogged when fuel gels in cold weather. It is also prone to plugging with really bad fuel.

Tony

TonyJetta said:

Do you see a lot of air in the fuel lines?

I know Passat's are prone to this: There is a check valve in the fuel tank pickup assy that can get clogged when fuel gels in cold weather. It is also prone to plugging with really bad fuel.

Tony

Click to expand...

I see a bit of small bubbles in the feed line while the car is idling/throttled. I pulled the fuel sending unit yesterday while it was rainining. I didn't see a strainer or check valve. I think the sending unit was revision D. Maybe this is an updated Canadian version. It just had a plastic mesh grill built into the bottom (like a rice strainer). It was all clean.

honda_vtec2 said:

I see a bit of small bubbles in the feed line while the car is idling/throttled.

Click to expand...

Do you get more bubbles as the rpm increases?

You may have more bubbles under a load. Kinda hard to see, unless you are on a chassis dyno.

How old is the fuel filter? The seals on the 'T'?

It may be of value to pull a vacuum on the fuel filter, into a catch can that comes with a mity-vac setup. This will give you an idea of how much vacuum is required to pull fuel from the tank, indicating if there is a restriction the fuel line.

Tony

TonyJetta said:

Do you get more bubbles as the rpm increases?

You may have more bubbles under a load. Kinda hard to see, unless you are on a chassis dyno.

How old is the fuel filter? The seals on the 'T'?

It may be of value to pull a vacuum on the fuel filter, into a catch can that comes with a mity-vac setup. This will give you an idea of how much vacuum is required to pull fuel from the tank, indicating if there is a restriction the fuel line.

Tony

Click to expand...

I changed the fuel filter and checked the T fitting. It has a steady stream of small air bubbles when i rev the car up. I'm getting a scan courtesy of P2b tomorrow. So i'll have more info then.

I read a post on here that the pump might have some a stuck cold start plunger valve. I'm hoping it doesn't.

honda_vtec2 said:

I read a post on here that the pump might have some a stuck cold start plunger valve. I'm hoping it doesn't.

Click to expand...

Try this post. The case pressure relief valve.

Tony

TonyJetta said:

Try this post. The case pressure relief valve.

Tony

Click to expand...

Hey thanks for the link. I remembered having it adjusted last October/November. I've put around 20k since on the car. Does it loosen up in such a short period of time?

car was scanned

Little update......

I had the car scanned today. No code errors

Ignition timing adaptation was reset to defaults. It was advanced +3 degrees.

When going into basic settings, the car would idle like crap and emit a lot of white smoke. In normal idle state car idles smoothly at 901 rpms with no smoke.

We checked group 4 settings. Ignition timing hovers all over the place from 2.2-8.6.

I don't know the numbers; it should be between the middle line and the upper line in the graph.

Tony

I wasn't aware that the timing could be adjusted by adaptation. Most people adjust the timing by loosening the injector pump and rotating it (like a distributor on the old gasoline cars).

The values you put up sound more like injection quantity.

For timing go to group 0, then click basic settings, then click tdi timing graph. Go to the pull down menu and pick your car. Engine has to be warm.

Injection quantity should not bounce around the range you listed. It should stay steady within a few tenths. Mine did that (97 passat). It stopped after running a few cans of diesel purge through it and bumping the adaptation value up to 3.5 or 4.

Go here to see how to use vag com o0n a tdi.

http://www.ross-tech.com/vag-com/cars/tdi.html

TonyJetta said:

I don't know the numbers; it should be between the middle line and the upper line in the graph.

Tony

Click to expand...

Static timing was set in the middle of the graph last year, via mechanical adjustment. When we checked it today. It shifted towards the bottom of the graph. At idle, ignition timing was sitting at 0 (no fluctuation. When checked in basic settings, it started to fluctuate like crazy with tons of white smoke coming out of the tailpipe. So it seems like the ECU is trying really hard to keep the adjustment within range, but can't.

Check mechanical timing. Rotate engine so injection pump sprocket pin hole is aligned. Check flywheel and see if tdc marks are aligned. It is sounding like your timing has slipped to retarded setting.

Ski in NC said:

Check mechanical timing. Rotate engine so injection pump sprocket pin hole is aligned. Check flywheel and see if tdc marks are aligned. It is sounding like your timing has slipped to retarded setting.

Click to expand...

I talked to a local guru and they will diagnose and repair the car. I'll be dropping it off tomorrow. This diagnostic and repair is out of my scope. So i had to give up. I've thought about checking TDC yesterday, but decided since i lack the knowledge, software and tools. I'd stop there.

Thanks for all the tips guys. I'll keep you posted on what the outcome is for this problem.

Ski in NC said:

Check mechanical timing. Rotate engine so injection pump sprocket pin hole is aligned. Check flywheel and see if tdc marks are aligned. It is sounding like your timing has slipped to retarded setting.

Click to expand...

This is a good suggestion - we should have done this when the car was here today. Actually, we should have done it several times - starting the engine in between - to see if we got the same result each time.

The car needs glow plugs to start if it's been allowed to cool for more than 15 minutes - otherwise it just cranks and blows white smoke. Cranking speed is well over the minimum required.

Once started, the engine idles nicely, no smoking, and all measuring blocks are well within specifications - in particular IQ is 3.6 and rock stable. No DTCs stored.

As soon as you go into group 0 basic settings, the engine starts to idle erratically and blow white smoke. The timing graph bounces rhythmically every few seconds from slightly retarded (but within spec), to off the chart advanced. and back to slightly retarded. Idle returns to normal and smoking stops as soon as you exit basic settings.

In group 4 basic settings, start of injection also bounces rhythmically every few seconds from around 2 degrees BTDC, up to around 8, and back again.

I was thinking the problem might be a loose crank sprocket causing the mechanical timing to move around, but it seems too rhythmic for that. Maybe an N108 problem?

Simon