98 Jetta TDi Hard Start

I had 98 Jetta TDi come in a couple of days ago that the owner was having no start, or long cranks before starting. Once started, the car would run just fine. He took it to a local shop in the Gainsville GA area, but they didn't have Vag-Com to read codes or really didn't know what to look for.

So after a couple of glow plugs and no help getting it started, I suggested that he needs to get the car scanned to see what faults he might have. He brought me the car and I found the car faulting the N109 fuel shut off and the N108 Start of fuel commencement faults.

I noticed his fuel return lines were wet, so I replaced those. The IP pump looked ok. I proceeded to draw fuel back to the injectors, bleed the injectors, and start the car, no problem. I proceeded to check fuel draw to the filter, and noticed as soon as I removed the vacuum, the fuel flow back toward the tank. So I went to the tank unit, and drew fuel from the supply line connection on the tank unit, and fuel flowed freely.

Next I went to the fuel line coming from the tank unit. There is a check valve located about 3 inches upstream of the tank unit. I removed the check valve and inspected it. The rubber seat in the check valve was dislodged, allowing the fuel in the supply line to drain back into the tank. I reseated it and checked its operation with a Mighty vac, reinstalled it, bled the line to the filter, and leak checked. No more retreating fuel when shut down.

Has anyone replaced or bought these "check valves"? I am looking for a part number. I am also looking for anyone closer to the Gainsville GA area that has a Vag-Com that might be able to help out from time to time?



Thanks, Ed

I just noticed your post on the long crank/no start. I am experiencing somewhat similar problem on my 99 beetle... and I did also what you did,pulled fuel from the hose going to the filter, and as soon as I let the vacuum go, it seems to drain right back to the tank. I didnt know if this was normal or not. Did you repair fix this issue, and if so were you able to locate a new check valve?

Howdy neighbor!!
I just posted a thread about theses check valves and the problem I had. I completely removed mine and havn't had any problems and have talked to others who have done the same without issues. Also I posted the part numbers for both check valves but they apply to the mk3 jetta, I don't think the NB has the same ones and might have them built into the fuel sender/pick up. Hope this helps

good repair

mrpat2 said:

I just noticed your post on the long crank/no start. I am experiencing somewhat similar problem on my 99 beetle... and I did also what you did,pulled fuel from the hose going to the filter, and as soon as I let the vacuum go, it seems to drain right back to the tank. I didnt know if this was normal or not. Did you repair fix this issue, and if so were you able to locate a new check valve?

Click to expand...

Yess, this repair did fix the issue, and no, I have not located a new check valve. Your Beetle may have the check valve in the tank unit. There are some write ups on removing the the tank unit and inspecting the pickup and check valve.

Let me know what you find.
Ed