Hard Starting Sometimes

Anyone have a suggestion for me:

2003 VW Jetta TDI 105k miles. Fuel filter replaced 10/2012. Buns only Cenex Roadmaster XL fuel with nice clean 100% biodiesel added per tank, about 3/4gallon, and a biocide also per tank 1 ounce. Engine runs smooth, and great no problems.

I had the same problem a year ago, and replacing fuel filter seems to fix the problem. NOw it's back again.

One day engine starts and runs fine, next day, I will roll engine several times,a bout 10 seconds per crank try and then finally starts.
I'm guessing loss of prime on Injection Pump, but I see no leaks anywhere from pump to injectors or back to fuel filer. No diesel anywhere, nice and clean. Hose clamps on filter filter replaced long time ago with radiator hose clamps. Hoses look good, no air bubbles in lines to IP.

So is it the fuel filter or IP? I put a touch of grease on the blue and black O rings on fuel filter before installing, as they slide on better and stay sealed better. Just a touch now, not alot. I know better.

I do not have Vag Com at this time, lost my cable and saving to buy again.

Thanks for all the help on this in advance.

coullee

Pinch off the feed line one day after you've parked the car for the night. If it starts right up the next day, you're getting air into the system (Most likely at the fuel filter)..

I think credit for this little trick goes to whitedog, he's mentioned it before.

Feed line

LNXGUY

Thanks, I'm guessing you mean feed line from the fuel filter to the Inj. Pump. I'll try that. May have to replace feed line between the filter and IP or maybe it's just the fuel filter. I know others have complained of this.

thanks much,

Barrie, Ontario not to far from my cousin in St. Catharines, Ont. visited her last August. Beautiful area. She took me to Kitchener, her home town, and then to Whitby where my ancesters came back to the US about 1833. Toronto is huge for small town Wisconsin guy. thanks again.

Funny you mention St.Catharines, that's where I grew up

And yeah the feed from the filter to the IP is what I was referring to. Goodluck! I hope you get it sorted out.