Passat stalling

My sisters 4 cylinder 1992 Passat dies and then will start right up, sometimes run for a few minutes and sometimes will go for a couple of days. We replaced the fuel filter and the fuel pump in the gas tank.

The mechanic replaced the ignition switch and the rubber boot that connects the air filter to the engine. It acts like something is stopping up the fuel line. I looked in the tank when I replaced the fuel pump and didn't see anything

Last night she turned it off at the store and now it won't start at all. I checked the fuses that I thought it might be but all were OK. I didn't have time to check anything else, just towed it home, so I don't know if it has spark, but the exhaust did not smell like raw gas while we were turning it over.

I'ver read a lot of old posts most are a couple of years old. Anyone have any new info or ideas?

Could be the manifestation of a ratcher well known and easily solved problem in these cars: There is a relay in the fuse box which controls current to the ECU when ignition is on. And this relay frequently is faulty (broken contacts on a small circuit board), resulting in sporadic releases -> motor dies, but can often be restartet w/o problem. Replacement ic cheap, you just need to find out which of the relays is the culprit. Numbers and placement in the fuse box change with models, number "109" is frequently mentioned.

Wolfgang

compression fuel ign Your engine is lacking one, or more, of the above.

I have seen new ign switches go bad in less than one week. It even happened to my 91 Passat, so I rebuilt my old switch. Listen for the MAIN fuel pump running (right rear side of vehicle) as someone cranks the engine over. (Maybe fuel pump relay) Carefully check for spark as someone cranks over the engine. Might be ign. coil, distributor, Coolant Temperature Sensor (unlikely in your sister's case), or many other things. :-(

later, dave (One out of many daves)

One thing you don't mention is the mini-filter in the fuel distributor (it's in the banjo bolt that connects the stainless steel feed line to the side of the fuel distributor). To check it just unbolt the line and check the inside of the banjo bolt, you should see a small screen inside which may be clogged. I remember having a problem with my GTI years ago and it turned out to be this filter. VW installs them at the factory to catch any crap that may be in the fuel tank during manufacture and are supposed to be removed at the dealership before sale (at least that's what I've been told).