Hard start, then die...Help!

00 Jetta TDI 5spd with 104k miles now. Only mechanical mod is the CAT fuel filter. In the morning before work (5am or so) I try to start, it will start very rough and idle for a couple seconds and then die. I will start it again and it will start even rougher, fluxuate idle and then will be ok. Any ideas? I have tried cycling the glow plugs three times, no dice either. Ambient temp is around 40-60 degrees F in the mornings here.

Please help!

THX!

Jason

I assume you checked and eliminated air leaks when you did the CAT filter install? Your problem is consistent with possible air in the lines...


Keith

How many miles on the CAT filter?

Probably 1500 miles on the filter? I can see bubbles randomly go through the clear fuel line, is this normal? Should I get a regular filter and switch back? The banjo fittings had barbed ends, I put them in the hose AND used the factory spring clamps over them. If I give it a tiny bit of pedal in the morning, about 1100-1200 rpm it will studder up and down but wont die. If I give it no pedal, it WILL die every time I start

I changed my hose clamps on a OEM filter, those clamps it comes with are crap.

You did check the anti-shudder valve.?

As long as you: 1) securely tightened the 19mm banjo bolts on the fuel lines, 2) used the O-ring on the center stem where the filter screws on, 3)and used good O-rings on the thermostatic T, there shouldn't be any air ingress into the fuel system.

I recently installed a CAT filter for someone else. We had a problem with the supplied, slightly oversized O-rings on the thermostatic T. The bottom one would go into the filter head, but the top one would roll up/deform and not go into the head. Solved the problem by using factory O-rings. Perhaps could be drawing air here if your case is the same. Try using the old O-rings if you still have them.

I also recommend altering the stainless steel clip that holds the T in place. If you look, it slides under the T, and holds it slightly elevated above the filter head. Top O-ring is barely in the filter head. Take a dremel tool w/ grinding stone, and hog out the clip opening until the T sits securely against the filter head. O-ring is now seated better.

Also, excellent suggestion was made to check you EGR/antishudder to see if it is mostly gunked close.

The banjo bolts are tight, and I bent the aluminum bracket "down" some so it would apply a slight pressure to the T fitting because it was just sitting there, nothing to hold it down. I changed out the orings that came WITH THE CAT KIT. I am noticing there is NO fuel in the main clear line to the pump upon startup, like it is draining back/out of the filter for some reason...

I will get some Orings from the dealer tomorrow if that might help. I can't smell/see any fuel anywhere.

Thanks for the progess so far, I would really love to fix this.....!!!!

Jason

The dealer wouldn't sell me bulk orings...any ideas on what size to look for elsewhere?