MK 1 Rabbit wont start

[TyeGTI]

My 1980 with a 84 GTI motor wont start. When I turn the ignition on, the fuel pump runs but when I turn the ignition to start it cuts out. The PO has bypassed the fuel pump relay and it runs constantly when the ignition is on. So it not cutting out like a stock system when it gets up to pressure. As soon as turn the key to crank over the pump cuts out.

Any thoughts on this

[WaterWheels]

Did it run before or did you buy it "as is"? The problem sounds like a splice was made into the X-mode power supply instead of the ignition power. Either one is wrong in my book as it makes the car dangerous in a way that is really not required, but hey . . . This power supply is what runs things like the rear window de-fogger or the heater fan or windshield wipers. Things that are not required for the engine to start, so more power can be directed to the starter on cold days. These things lose power when the key is switched to the cranking position and power comes back when the key is released to the run position.

[TyeGTI]

Did it run before or did you buy it "as is"? The problem sounds like a splice was made into the X-mode power supply instead of the ignition power. Either one is wrong in my book as it makes the car dangerous in a way that is really not required, but hey . . . This power supply is what runs things like the rear window de-fogger or the heater fan or windshield wipers. Things that are not required for the engine to start, so more power can be directed to the starter on cold days. These things lose power when the key is switched to the cranking position and power comes back when the key is released to the run position.

I did run i drove it from were I store it to the garage to work on it. Went to put it back and it wouldn't start. I didn't do anything to the electrical or fuel system.

[cuppie]

It sounds like you have a bad ignition switch. Very common failure mode:
X contact (hot in Run only) works; terminal 15 (Run power) works; term. 50 (Start) works. But, term. 15 drops out when turned to Start.
Get yourself a quality new switch (I'd only use one from the dealer, or from GAP - nothing else.)
(and, if you don't still have the original, get a fuel pump relay, too. Hell, even if you do, get a new one for a spare! Same suppliers recommended.)
New switch in hand, just drop the column plastic, unplug old switch, and plug in new. Carefully operate with a screwdriver. Car start? Tear into the column & replace the switch.

[Esevw]

Also check your grounds, even though you didn't touch them they could've been loose or corroded from last owner... Never know. Check.

[TyeGTI]

I going to guess water in the fuse box because I found holes in the rain tray right above it.