Hard start problem, still after going every hard start thread

Hello, guys, I've been going trough the forum for the last months trying to find some thread with a solution to my problem. I have tried many tings but did not prevail yet.

Here it is:
The Problem : My 2000 1.9 ALH jetta has been giving me hard start problems for almost the last year, The problem seem to have come gradually but I’m not really sure about that since I realy started noticing in last sept (warm weather going in colder weather). Cold or warm (-20 to +30 DegC) it takes 5 to 10 seconds of cranking to start. I’ts worst during colder temp but probably due to lower Cold Cranking Amps available from the battery.


Wats been checked:
- Fuel filter changed for a new one since the start of the symptoms, fuel flow restriction problems checked with Mighty Vac, * it needs about 2 inHg to pull up to the pump.
- Glow plugs changed, everything seems fine in this area *resistances and amp draw are in specs.
- Fuel lines replaced with clear diesel proof tubing * No air in the supply and return side ( aside from really small bubbles sometimes
- Intake manifold * cleaned the propane/compressed air way about 50k ago and partially cleaned by my local trusted garage in fall 2012 (trying to cure my hard start problem)
-Compression test done on all 4 cylinders with values all close to 500psi
-Injectors tip (205’s) changed and pop tested twice (after suspecting dripping nozzles), last time from Kerma TDI about a week ago.
- Anti-shudder valve working correctly (not closed)
- No apparent external fuel leak from the IP/injector hose/injectors/return lines
- New battery in spring 2012 * Amperage draw at start up was within specs according to the local garage
- New starter in winter 2012 * Starter speed higher than the needed 300 RPM
- Timing (from VCDS lite) I’ve played a bit with it and now it’s a bit advanced but within specs
- IQ is now at 3.8 - 4.2 at idle * curiously it was at 2.4 when I installed the new injector from Kerma and when I readapt it to 4 it takes more time to start.
- MAF was changed in spring of 2012 and cured an unregulated idle problem at that time.

Whats suppected now:

- The car seems to drink a bit of coolant * maybe 500ml per 2-3 months. It smells a mini bit like burnt coolant when I crank and finally start the car. No air bubbles are apparent in the coolant reservoir and no noticeable coolant in the oil (since last oil change in November). Smoke is not colored appart from when very high rev situation occur (black smoke)

-It seems some of my glow plug treads are leaking a bit of cylinder pressure. When I recently purged the metal fuel line to get the new injectors in, diesel had puddle around the glow plug hole/threads, I could see some bubbles coming from the glow plug sides. It really was not much and the car runs flawlessly once its started. Although compression numbers where fine, I remember I used the glow plug holes to take the compression numbers. It would be a bit weird considering the small amount of air that seem to leak that this would be my problem.

- Pump case pressure valve (or whatever it's called) with the little plunger and spring on the passenger side of the IP * I've taken it out a first time and it was in pieces, reassembled it tried the car (no change). took it out minutes after that and it was still dissasembled. I re-reassembled it and didn't touvch it again since it did'nt change a ting. What's this valve for ? I could not find much info on this one.

- Could a vaccum problem cause a hard start situation ? My vaccum lines are a bit old and I get the dreaded limp mode when I realy step on it (wich I suspect is caused by my sticky vanes turbo)

- could an internal leak in the IP give me the hard start problem, Would I sea air in the fuel stream on the return side ?



- Any more advice would be appreciated, I can provide data stream from VCDS lite

Thanks guys

Are you running WVO?

I have been in the past (last year and for about 50K prior to that) but the clear fuel lines show that it's not WVO coming in and out of the IP since the start of my problems a year ago.

Ive notice this wknd that the car takes longer to start when at full operating temp

WVO might have gotten the QA gummy??

Do you get a big puff of smoke once engine fires off after a long crank? If not, there was no fuel being injected during the long crank. Either qa sticky or air is getting into pump body. You can put a clear line on the outlet of IP and see if there is more air coming out than going in.

I think i'll disassemble thé pump cover. I read on à différent post that à seal replacement might not be totaly needed. I can still adjust qa via vagcom and it seems to be working fine (iq is changing). As for air in thé lines there seems to be only tinny little bubble that come and go every 5-10 seconds in thé return line when running. I have not noticed à tremendous smoke output when starting. à bitt of blue smoke but realy not much even after 10 sec crank time. When thé fuel injector nut are cracked open while cranking I get fuel streams right away when cranking

Could it be suspected that fuel stream at thé nits while cranking might not necessarly meen high enough pressure is built up for injection ?

snowboardphil said:

Could it be suspected that fuel stream at thé nits while cranking might not necessarly meen high enough pressure is built up for injection ?

Click to expand...

Yep, with air in pump, lines will still spit, but will not build enough pressure to actually inject. Spit from the lines is not proof that all is well.

thanks for thé idea, from my understanding if thé qa is gummed up, it would then prevent thé stary stroke iq (20-30 mg/s ) to be reach for proper initial injection ? Is there à way to check that with vcds (addaptation of some kind to see if starting gets better pr worst)

sorry for thé bad orthograph im on à smartphone keyboard here.