I have a 1990 VW Jetta that is not firing to start. Both the negative and positive sides of the coil has power

Question

I use a regular bulb as a test light. I connect the positive side of the bulb to the negative side of the coil and ground the other side. When I turn the iginition on; the bulb light up, indicating that the negative side of the coil is getting power. However when I turn the iginition to start the car, the bulb only goes off. I was told to use a test light and the light should go on and off when turning the ignition to start the car. Is the bulb not going on and off indicating that the hall effect in the distributor not working or do I need to use a conventional test light to check the hall effect?

Answer 1

worn dissy sparking plugs us or nackerd leads

Answer 2

Lets check the fuseable link. Open hood. Engine is off.. Disconnect the negative side of the battery and leave disconnected..an accidental short will blow fuses and we don't want to fix more than necessary. The glow plugs are in front of you on the side of the block, tied together to each other by a strip of copper banding which is nutted on to the end of the plugs. At the extreme right plug is where the band ends. Heavy gage Wiring is also under that one nut(probably red/white). This wire if you follow it should take you to a little plastic box on the firewall where it goes into and same wire comes out of and goes to the battery. That little plastic box is a cover. Pop it off. It is OK if you use a metal screwdriver( the battery is disconnected, remember?) Behind the cover you will see the wire that entered from one side stop under a philip screw and the wire from the battery on the other side stop under a different phillip screw. In between the 2 screws there should be a strip of " grey metal" that joins the two screws together. The fuseable link that "when it blows, leaves no connection" If the grey strip is missing what joins wire A to wire B? Now you have to go to dealer to get another strip and install(remember no battery connection while you are inthere with a screwdriver) {I found this rather stupid. Mine blew too, on 2 cars. What if I was in the bush? Took the wires out of the box and used the Phillip screw and nut and bolted the two ends together and used electrician's tape and enclosed that. NOT a problem point anymore. HOWEVER, should there be a real heavy short my car wiring will catch on fire. That is what the fuse was for. } Maybe my story helped you. Orr,If the link is still there, it could be the "glow plug relay" Before replacing the relay, make sure the link is there because even a new relay won't work if it can't get the power and all the power goes thru that fuseable link. It has to do with this area of the car, diesels are simple. Remember to hook the battery back up and you are good to go.

Answer 3

there are many ways to test ie:
contect every think up -remove the king leadfrom the distibutor (the lead between the coil and the distributor) using insulated pliers hold the end close to a good earth on the engine then get a freind to turn over the car if u see a good spark replace the lead bk on your problem lies elsewhere prob the distributor cap or plugs or leads .

Answer 4

take th ht lead from the center of the distributer cap hold it about 1/2" from the engine block and get someone to turn the key to start you should get a HT spark if not then the fault is your coil if yes then your fault could be the carbon contact in the distributer capif point they might need replacing if electronic it could be the air gap on the rotor

Answer 5

If I remember correctly, I had a similar problem with a Passat many many years ago.

It turned out that there was another unit that sat very close to or underneath the coil that had failed - the coil itself was ok. Check your haynes manual if you have one.

Answer 6

A regular light might be too slow. A high speed test light would be better.

Answer 7

have you got petrol in it?