TheSamba.com :: View topic - '84 Rabbit Diesel..Won't Run..Where To Start?

Sun Jun 03, 2012 12:29 pm

Just bought a '84 Rabbit L Diesel yesterday. Here's the info.

~250K
-5 Speed
-Diesel

It had been sitting for 5+ years, at least.

Previous owner said he "thinks" the injection pump jumped a tooth.

Yesterday, I drug it home and immediately tried to get it running. I did the rough check of the pump timing, by lining up the cam with the gasket surface, checking for TDC on the flywheel, and then checking to see if the pump pulley hole lined up with the bolt.....it was spot on, or certainly VERY close.

I then proceeded to prime the IP as best I could....I pulled off the line from the fuel filter and manually filled up the IP with fresh fuel. I then stuck the inlet line for the pump into a fresh jug of diesel. I unplugged the return line to the tank and ran it into an empty jug, to see if the pump was pulling fuel when I cranked it.

Threw a brand new battery in it and cranked over for awhile......no fuel was coming out of the "return" hose that I had running into a jug.

I then proceeded to crack open the injector lines a little, one at a time. When cranking, they all spit out fuel with moderate pressure.

I have not checked the glow circuit, I assume they are all junk but, in the summer, would this cause a no start?? I was thinking it would at least sputter.

Also, I suppose the injectors could be junk as well.

Is there a way to check the IP for the correct "pressure"....to figure out if it needs a rebuild?

I know I should prob do a compression test, too, but I'm going to wait to spend the $$ on the tester. What else can I dive into??

Thank you,
Mitch

Mon Jun 04, 2012 8:31 am

Maybe the injectors are plugged from sitting so long. You could unscrew them and soak them in solvent for awhile.

These injection pumps are a PITA to prime. I have (very carefully) used a tiny squirt of starting fluid while cranking to get some activity. Don't squirt to much or it'll blow up the motor! I have also used WD-40 to aid in priming.

Mon Jun 04, 2012 4:42 pm

Thank you for the reply, Shadd.

I am going to pull the injectors tonight and bring them to my local diesel shop for testing.

Mitch

Wed Jun 06, 2012 8:28 am

Alot of people prime them with atf if they have been sitting dry for awhile. Glow plugs do need to be working, also try using the cold start pull

Fri Jun 22, 2012 5:53 pm

Well, eventually found that the Cam was off a tooth. Tried to loosen up the belt and back it off a tooth but ended up making it like 5 teeth off....I didn't have the cam locked and it rolled back when I tightened it up. Just got a new belt and tensioner and am going to try putting a new one on tomorrow, utilizing a cam lock & IP lock. Wish me luck.

Mitch

Sun Jun 24, 2012 12:22 am

If you don't have any fuel coming out of the return lines the most likely problem is the banjo bolt is plugged. That's the bolt holding the fuel return line fitting on the top of the injector pump. It's a hollow bolt and will have very small holes in it. It also has a fine mesh screen inside that clogs easily and with fuel that has been sitting a long time, algae has surely grown in there. The quick fix is to drill it out and run without a screen until you can get a new bolt. With the right size drill, the screen should twist out. Make sure you get any shavings out of it, it needs to be clean, clean, clean as with all of your fuel components. The key to the VW diesel is that constant flow of fuel to the engine and returning.