Engine suddenly stops running?

I have a strange problem in that my 96 passat has had the engine die on 2 occasions, both times about 3 miles from my house on the first drive of the day.

The first time I noticed that there was some air in my fuel line going to the filter. (I'm running biodiesel and put in a prefilter with some clear fuel line) It seemed that a line was slightly loose and I tightened it up. It ran fine for over 100 miles then this morning it suddenly quit again. But this time the fuel lines had no air in them, so I don't think it's a filtering issue and if it was I don't think it would start up and run perfectly normal at highway speeds.

It seems to be something electrical, but there's no CEL and nothing else obvious.


When it dies, it's been when I'm driving down the road about 30 mph and the engine suddenly stops, oil pressure light is flashing, I pull over and it won't restart. After about 5 minutes of waiting. It restarted and ran fine, for the next couple drives of over 150 miles of highway driving.

I replaced the 109 relay about 2 years ago with the grey one as a preventive measure, and I'm thinking maybe I should try putting the old one that worked back in for a while or get a new one?


Any suggestions?

If the glow plug light does not come on when it doesn't start, try the relay 109. Try the old one, if it was good when you took it out.

If that's not it, I'd clean the grounds.

I hooked up my Vagcom and came up with the following codes, which I cleared and they haven't come back yet. But I don't know if there's really any connection.

Controller: 028 906 021 GQ
Component: 1,9l R4 EDC G40SG 1420
Coding: 00002
Shop #: WSC 10001
1 Fault Found:
00575 - Intake Manifold Pressure
17-00 - Control Difference

Can't imagine it would cause the car to stop. When the Relay 109 cuts power, the computer doesn't set a code, since it's, shall we say, cut off from power.

Modulating piston movement determined by G149
To check the quantity adjuster and to calculate the
fuel quantity, the control unit requires feedback on
the actual quantity of fuel injected. Sender G149 is
permanently linked to the eccentric shaft of the
quantity adjuster. It signals the position of the shaft
to the control unit, and thus the exact position of the
modulating piston.
Substitute function
If the sender fails, the engine is turned off for safety
reasons.

Click to expand...

This is from the industrial engine technical manual. Perhaps you have a sporadic open or short to the g149 quantity adjuster or you could even have it getting stuck...

What are the symptoms upon restart? Glow Plug light, crank or no crank, trying to start and not catching, etc.

Hi,
Pull the ecu and open it. Replace the vaccume hose inside it with a piece of hose similar to the fuel return lines on the injectors.
Jeff

???? I think that's the wrong size hose, and a problem there wouldn't cause the car to stop running. Throwing boost codes, limp mode, yes. Total shutoff, no.

This is electrical. 109, bad connection, really loose ground.

I had the same problem this summer. Replaced the relay 109,
cleaned up the grounds and greased them a little bit.
No problems since then.

I checked all the hoses and they were seemed OK. Also it was sudden stoppage. And when it did restart everything was perfectly fine. No lights, smoke...etc.

Yesterday I replaced the 109 relay, (even though I put in a new one 2 years ago for good measure) and I removed and cleaned the battery terminals. I've driven it now for about 200 miles running around and it's been working fine.

So I'm assuming it was probably the 109 relay was failing. I bought a second one to keep in the car. Or use it on my other Passat when it dies!

Thanks again for all the suggestions!