Glow plugs troubleshooting

[addautomotive]

Ok, I'm on my second set of glowplugs in 8 months, and the car (1996 1.9 AAZ) is starting poorly in the cold again. Last night I pulled the easiest glowplug; it glowed but it's already starting to look pretty bad, after only 4 months.

Last night I ran a wire off the glowplug "bus bar" to a light on the dash, so I could see how long the glow plugs were staying on.

Here's what I found:
-If I turn the ignition key, but don't actually start the engine, they stay on for 10-15 seconds.
-When I start the car, they are staying on for about 2 minutes... even today which was relatively mild (8* Celcius).

Is this normal?

[wyldman]

Yes,it's normal.The glow plugs will stay on for a few mins after startup to help it run better.These plugs (if you have the correct ones with the tapered tips) are designed for this purpose,and should hold up just fine.Is it possible you got the wrong glow plugs ?

[addautomotive]

Thanks for the reply, Wyldman.

Yes, I have the correct tapered plugs. I guess I'll have to pull them all to see if one is burned out completely.

[wyldman]

You don't have to pull them out to see.Either disconnect the bus bar,and check them individually with a test light or ohmmeter,or do an amp draw test on all of them together.If one (or more) is bad,the total amp draw will be too low.

[addautomotive]

Good plan... they should be drawing about 8 amps each, correct?

If I get into taking off the bus bar, I'll pull the injectors first... makes it much easier to access everything, and I can check for coking etc..

As for taking off the bus bar... if I do that I think I'll wire each plug individually... that will make issues like this much easier in the future.

[wyldman]

I never take the injectors out.It's tight,but you can get in there.Use an 8mm ratchet wrench on the bus bar nuts.

Current draw is usually around 50 amps for good plugs (it will surge higher at first).If it's lower,you have a bag plug(s).

[commuter boy]

After dropping the first few leetle glow plug nuts behind the fuel pump, I've taken to pulling the injectors to test the glow plugs.

But then I've got the proper Hazmet wrench to undo the fuel lines, so it's a pretty painless procedure for me.

A poor injector pattern can wear out the glow plugs pretty quickly I'm told.  Maybe get them pop tested while they're out?

[addautomotive]

A poor injector pattern can wear out the glow plugs pretty quickly I'm told.  Maybe get them pop tested while they're out?

Did that in the fall... had Smog do up a set of injectors with GTD nozzles. I did that because I figured I had leaky injectors, causing the GP issues.

[addautomotive]

OK... an update:

The light that I have wired directly to the glow plugs is just TOO COOL.

I noticed something very strange last night after work. I open the door, get it, then close the door.... THE LIGHT COMES ON, and stays on for 1 minute! At this point, the key isn't even in the ignition!

Thoughts?

[QuickTD]

I noticed something very strange last night after work. I open the door, get it, then close the door.... THE LIGHT COMES ON, and stays on for 1 minute! At this point, the key isn't even in the ignition!

This is normal. All 95 and up 1.9TD's have this feature. The glow timer starts when the drivers door is closed. The timer will run for about 15 seconds or until you start the car. Often you won't see a glow plug light because the glow time will have already elapsed before you turned the key on. If you wait longer than 15 seconds to start the car, the timer will restart and you will see the glow plug light when you turn on the key.

 The glow plugs will only come on via the door switch on the second opening/closing of the door after the engine has been shut off. If the door is subsequently opened and closed without starting the engine the glow plugs will not come on. This prevents the battery from draining if the door is repeatedly opened and closed. If the door triggered cycle has been "used" already, the glow timer will function normally and start when you turn on the key.

[addautomotive]

My head is spinning.

Quick TD... you da man!

So, the question remains... why is my car starting so hard??

[addautomotive]

After reading through some old posts... I think I may have the wrong glow plugs. That would explain why I'm burning them up so quickly. Th elocal VW guys told me to use the same ones as the 1.6 diesels... but they're not duraterm GPs, are they?

I can't seem to find the part # for Bosch glowplugs for the AAZ. Anyone know what it is?

Also, has anyone ever used VSP (energy plus) glow plugs? I have some that say they replace Bosch #
(BOSCH):0250201004/015/021/032
(BOSCH):0250201001/008/005/006/009/019/027
(BOSCH):0250201012

and Beru#
(BERU):601MT/0100221105
(BERU):603MJ/0100221107/607MJ/633MJ/609MJ/0100221 114/613MJ/0100221118/636MJ/0100221133
(BERU):657MJ/0100221141