1998 Jetta Issues!

[linsChaho]

I have a '98 TDI with the 1z engine. I've confirmed this by the sticker on the timing cover and the March manufacturing date. Previously I was having priming issues but have since sorted those out I think. The car will start and run smooth for about two seconds before shutting off. Startup is rather rough. Sometimes it shuts down smooth like I've turned the key and other times it sputters briefly and dies. I have also noticed that the car WILL NOT start (it will crank but not start) if the glow plug light doesn't come on when the ignition switch is turned to the on position. Below I'll list what I've done and where my mind is at for what's wrong.

What I've done:
- Primed the system. I have a decent mist of fu https://9apps.ooo/ el spraying from the injector lines when I crack them open. It isn't a stream as I've seen in videos but it is quite a bit of fuel and sprays consistently until the car shuts down. This makes me think it isn't a fuel starvation issue.
- The car will run with one or two injectors open but shuts down. This is how I've verified the amount of fuel coming from the injector lines.
- I have the fuel shut off solenoid hardwired to the battery to force it open. I disconnected the factory wire to prevent current flow into the ignition system.
- The electronic throttle is unresponsive once the car starts.

What I'm thinking:
- There is some safety mechanism that is causing the car to shut off after it starts. I'm led to this conclusion based on the consistency of the start up and shut down process.
- The glow plug system could be causing the shut down. The previous owner took a shortcut route when changing the glow plug harness and spliced the wires together rather than properly installing them in the harness.
- I ran a VCDS scan and received an airbag code, could this cause the system to prevent the car from running?
- Also threw "00532 Supply B+ 07-10 Signal too low - Intermittent"
- Could it also be the immobilizer? I've seen mixed answers as to whether or not this car has one.

 

[garciapiano]

No immobilizer on these models.
Check for fuel in the supply line. Incorrect timing can also create running issues.

 

[burpod]

Sounds like you have a relay 109 problem, or wiring issue between ignition switch, ecu and or 109. Glow plug light not coming in means ecu isn't getting power. Will crank but not start

 

[turbodieseldyke]

the car WILL NOT start (it will crank but not start) if the glow plug light doesn't come on when the ignition switch is turned to the on position.

Sounds like you have a relay 109 problem,

Locate the 109 in your fuse/relay panel down by the brake pedal. When that light fails to light up, turn the key off, then wiggle or tap on that relay, the key on again. Repeat a few times until it finally lights up, then start it up.

 

[Steve Addy]

Get rid of the black 109 relay and replace with the grey 109 relay. They can be found on many mk4 cars at the JY too.

Steve

 

[Mongler98]

while there is no immobilizer so to say on these older cars. they DO have a security box that if it goes bad it must be jumped. its behind the driver left side vent off in the back to the right. jump the 2 big red wires with the same gauge wire and some stakeon connectors.
also same advice on the 109 relay.

 

[Abacus]

That box (the convenience module) has nothing to do with the glow plug light.

TDD is right, push in on the relay to make sure it's seated. I've seen quite a few that come loose, especially when the fuse box isn't put back right and is tilted down.

Steve is also right in that the early black 109 relays had internal soldering issues that would break the connection at varying times. Never had an issue with the grey ones.