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1998 Jetta Starts But Doesn't Run - fouled plugs

My wife’s 98 Jetta missed from time to time, especially (it seemed) when raining. A mechanic told her she needed to replace one spark plug. Then it sat unused for about 6 months or so. Battery was dead, so jumped it. It started but wouldn’t stay running. I changed all 6 spark plugs and cables. Noted rusty-looking dust around one of the plugs I removed, some of which I’m sure made its way into the chamber upon removal. Replaced battery. Car still will start, but not stay running. Checked plugs and found them covered in gas and/or oil. Cleaned plugs, tried to start once, started right away but still did not run and plugs again fouled with gas and/or oil. Should I call a tow truck or is there something else I can try? Thanks.

Again clean the plugs, but this time before you start the car, hold the accelerator to the floor. Keep it there and start the car. When it starts, take your foot off of the accelerator and see if that helps. Most fuel-injected cars recognize when you are starting them with the accelerator floored and assume that means you are manually clearing a flooded condition. That might help.

If it doesn’t, you may have a coil or spark plug wire problem (the “especially when raining” comment makes me thing this), or you may have a stuck injector or faulty fuel pressure regulator. At worst, an ECM problem.

Don’t worry about the rusty stuff getting in to the cylinder, it was blown right out of the exhaust as soon as you hit the key.

Best of luck.

Is there too much fuel, or too little spark? The engine computer controls fuel injection amount based, partly, on what the engine coolant temperature (ect) sensor tells it. The ect can be checked (resistance values), or simply changed outright.
A dirty air filter can cause an engine to choke and run rich.
Weak spark can be caused by the ignition coil, or the ignition module. Again, there are checks for those. The spark rate can be checked, visually, with clip on test lights, or a timing light.

Thanks for the suggestion, I’ll try to start it with the pedal floored after work.

I had already changed the wires, so hopefully that isn’t the issue.

Not a car guy, and lacking in tools here, so if clearing the flooded condition doesn’t work, would it be with my powers to check the injector or pressure regulator?

Noooot really, unfortunately.

This is a VR6 Jetta, isn’t it?

Yeah, VR6. I’ll just do what I can and keep the towing number handy.

Thanks again.

Dirty air fillter, eh. Sat for six months? How about a mouse nest in the air cleaner box or elsewhere in the intake tract?

Did you ever solve this? It sounds like the problem we are having with our 1998 Jetta.