Engine Start Weird

[BigD]

Sorry guys, time to stop lurking and ask another question.

'85 Golf 1.6L.  Cold start or hot start doesn't matter and not all the time.
Turn key, wait for glow plug light to go out, start engine.  Engine will start, but will stall when I let go of the key and the starter is no longer engaged.  Attempt start cycle again. same result.  In order to get the engine started, I have to keep the starter engaged feed the fuel to her until she keeps running on her own.  This most often works, however, if I let off the accelerator too quickly, she will stall again.  Once running, however, she runs great, no smoke, rough idle, nothing.

This "start-stall" cycle can last up to 20 minutes and, as I said, is intermittent.  Not a clue.

I will admit that I am not too genned up on diesels and how they work, so here I am, asking for the experts to help.

[motomike33y]

I had similar problem on an old jetta-problem was in relay to injection pump.  I fixed it by running a switch and hot wire to the IP so I could turn it on to run, and turn it off when I shut off vehicle.

[BigD]

you mean to the fuel stop valve?  Because my pump is mechanical and the only wire to it goes to the fuel stop valve.

[motomike33y]

yes.  On mine, the only time it was getting power(and holding the magnetic switch open)was via the starting circuit.  Test it by running a small jumper to the IP stop switch from your battery and see if it will start and stay running.  May want to also check that the stop switch is working right with that jumper.  It should click audibly when you touch the power lead to it.

[smutts]

motomike33y is on the money.
Most likely the ignition switch is on its way out, (they all do that Sir!), it can be swapped, but need to look up on the Mk2 forums for it somewhere as it is a while since I lost the only key for the car on the day that I bought it....DOH! and had to swap the entire set of locks with a scrap car.

[bajacalal]

The ignition switch on these cars often fails, when you replace it you will see why, it's made of plastic and about the size of a U.S. quarter.

You don't need to replace the lock cylinder (unless it is bad, does it feel loose?) the electrical part is separate and goes behind the lock cylinder. I've done a few, you have to take off the steering wheel and switches on the column but IMO it's easy, a 1 hour job with time for a snack/beer.

From what you described, it also sounds like you may be getting air in the fuel line while then engine is shut off.