long cranking time

I am the new owner of a 96 passat 150k
it has a new injection pump and timing belt 1100miles on it,
2nd new battery in a few months(previous owner had start problems i guess )
first i had a MAF sensor problem, (no power, no rpm) I cleaned it and it was good, then after about a week, it developed a hard start 10 seconds of cranking
I adjusted the timing(it was advanced above specs) no improvement
replaced coolant temp sensor,fuel filter
starter sounds strong, no air bubbles in fuel, no smoke
i ordered new glow plugs, because they are all bad, but temp has no effect on starting
i don't know where to go next i have been reading on here for days
any help for a tdi newbie?

Scmeone's going to ask: where'd the pump come from.

KLXD said:

Scmeone's going to ask: where'd the pump come from.

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Well it's hard to know without calling the mechanic in question(PO work), looking at the price ($95.00 r&r) i assume they just did the basic seals, but i guess i should talk to them(not on your list of mechanics)

Did you only adjust pump timing, or did you check cam/crank/pump relation all at once?

Does the pump have any markings? Is it an OEM pump?

fase2000TDI said:

Did you only adjust pump timing, or did you check cam/crank/pump relation all at once?

Does the pump have any markings? Is it an OEM pump?

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I only adjusted the pump timing, i figured since it worked before they at least put the belt on right.

the pump is a bosch and looks pretty new or at least very clean.
maybe the PO bought it elsewhere and the $95 was for installation?

if the belt was off wouldn't it show up on the vag-com reading?

If there's nothing on the invoice about the pump, then you don't know if the replaced unit was new, rebuilt, or used from some unverified source.

If the timing is indeed set correctly (and since you can't/didn't verify that with a known good mechanic) then all bets are off.

You must have the timing set with the cam and crank in agreement, the injection pump set correctly, with belt tensioned, the engine turned over by hand twice, then the timing rechecked. This is so you can really check things over before starting so you have a known quantity when the engine is cranked.

If it still starts hard, then you have other things to check. For example,

1) what is the compression on all cylinders?
2) are the glow plugs functioning well?
3) does the MAF really work within proper parameters?
4) is the fuel filter new (i.e. does it flow fuel easily because it is not clogged)?

The hard starting could be a lot of things. Maybe the compression is bad, maybe the MAF isn't working well, maybe the glow plugs don't warm the cylinders, maybe the injection pump isn't building internal pressure sufficient to operate the advance solenoid. Lots of maybes. A good TDI mechanic can sort these issues. An independent VW shop that only sees 1 TDI every 18 months won't know anything.

does this mean anything?

could it be injector problem?

Also the MAF sensor is reading a bit above parameters while at idle until the engine warms
starts at like 382mg/H then settles down to 370mg/H after some use

i haven't done a compression test,
the glow plugs are bad, but hopefully will replace them today(same problem w/engine warm)
MAF seems good, except for above issue
fuel filter is a new bosch filter

i don't want to mess with the belt, unless i have to, it does start and the timing is good with the vag-com, after i did a slight adjust( belts do stretch)
It was starting fine when i first got it, so that also tells me the belt was installed correctly.(i hope)

i put in new glow plugs, no change
it cranks about 5-8 seconds then starts
same if maf is disconnected or if coolant temp sensor is disconnected
i found a post that says the vag-com reading is normal for no value on #4
maybe i'll try some diesel purge and clean my injectors
my starter sticks sometimes now, guess it doesn't like that extra work
any other vag-com stuff i can try?

Check cam to crank timing to pump timing.. Vagcom isn't magic.

belt timing checked out fine...

SCMountainDiesel said:

belt timing checked out fine...

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Using cam lock tool and verifying TDC on flywheel mark and pump pin engaged?

SCMountainDiesel said:

...
i don't want to mess with the belt, unless i have to, it does start and the timing is good with the vag-com, after i did a slight adjust( belts do stretch)

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Maybe, but you'd be hard-pressed to be able to measure it.

SCMountainDiesel said:

It was starting fine when i first got it, so that also tells me the belt was installed correctly.(i hope)

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What it doesn't tell you is whether the IP pulley bolts were torqued correctly or if the tensioner was done correctly to prevent movement.

If you set up VCDS to basic and see that the graph is showing timing hitting the correct region on the graph, then you might have a bad injection pump. If the vane pump inside the injection pump takes a few cranks to build sufficient pressure to operate the advance solenoid, or if fuel is draining back to the tank when the car sits for a sufficiently long period of time, then either of those might cause the symptoms you describe.

i had a similiar issue with it cranking and cranking but no start until 10 or 20 seconds, no i was not cranking the whole time, and replaced the crankshaft sensor and walla.

fase2000TDI said:

Using cam lock tool and verifying TDC on flywheel mark and pump pin engaged?

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yes, i had the tools from my old rabbit

Powder Hound said:

Maybe, but you'd be hard-pressed to be able to measure it.
What it doesn't tell you is whether the IP pulley bolts were torqued correctly or if the tensioner was done correctly to prevent movement.
If you set up VCDS to basic and see that the graph is showing timing hitting the correct region on the graph, then you might have a bad injection pump. If the vane pump inside the injection pump takes a few cranks to build sufficient pressure to operate the advance solenoid, or if fuel is draining back to the tank when the car sits for a sufficiently long period of time, then either of those might cause the symptoms you describe.

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well the advance solenoid sounds possible, but fuel drain back isn't likely because if i shut off the engine and restart it still takes the same amount of cranking

I found the problem, fuel tank isn't venting. PO had the cap on loose and of course I tightened it after I filled up. Well I loosened that cap and it fired right up.
Is there a vent on these tanks or is it just in the cap?

found it vents in the rubber area around the cap, hose was full of dirt, also did vent button mod while i was there