Glow plug issue and some general questions

[tbones]

Hi gang,

I'm still troubleshooting issues with Sunny, my 1Z powered syncro Westy.

I'm troubleshooting the glowplug relay system, need a little advice. I'm asking here, since the 1Z motor came in the passat and Jetta. I'm including some pics, also

Here's the info I have:

THE ECU code is 028 906 021 ED

GLOW PLUG RELAY: KAE 2.400.210 (the relay APPEARS to be ok, and after removing cover, the points were not very pitted, and everything is clean, bright and not burnt-smelling. (see pic)

the van starts (relatively) easy IF I have someone crank engine over WHILE I'm manually closing the glow plug relay (with the plastic cover off, and me squeezing the contact points closed just before, and while cranking)

It's late, so I can't diagnose further tonight, but i'm ASSUMING that the glowplug is not getting power to close the loop when cranking. can someone tell me:



1. do I have a correct ECU (or what IS the 021 ED model out of... (I've only seen the -021FE and 021GQ previously in my 1Z motors)

2.am I correct to assume that the glow plug system is working, and that I just need to find out WHY the relay contact points are not getting the needed 12 volts to close?

3. Where would you recommend looking to find the culprit of no power to the glow plug relay while cranking?


Sorry... can't upload pics at the moment

 

[BigAndy]

From what I know of the glow plug system - they are powered on if the temperature is below a set threshold and the lower the temp, the longer the plugs are receiving current. I am not aware of the glowplugs continuing to get current while the engine is being turned over though.

 

[Steve Addy]

Anything above 40 the system will not pre-heat, the light should flash but then go out. Below 40 the system will glow properly.

The ED ECU is the first that was used for the US imported Mk3 Jetta with the 1Z engine, so basically in 1997 only. The JB ECU followed the ED and was considered to be more robust although I have a car with ED (and have since 2002) and never had a problem with the ECU. I believe it's safe to say that the JB ECU came with the switch to the AHU engine in the Mk3 in 1998.

The failing GP system will require some information to understand what's going on. First, is your GP relay marked 180? Also, is that relay remote mounted away from the fuse block in a separate relay holder that also has in line with it a maxi-fuse of 50 or 80 amps? Further, where is the large red wire that services the GP system installed in your fuse block? Finally, is your wiring harness in the Westy originally from a B4 Passat or a Mk3 Jetta TDI? There are differences in the B4 Passat cars for glow plugs between 96 and 97, and also between the B4 and the Mk3 cars. Knowing what you have will facilitate a resolution I think.

My first thought since you said that the system works properly when you close the contacts of the GP relay is that your coolant temp sensor isn't working right, but I thought you said in a prior post that the CTS was replaced or something so I'm only going to mention that just to get more info about it.

Steve

 

[tbones]

Hi All,

OK., I now know the glowplugs don't work until it's below 40F, and it's notthat cold here yet... so that's interesting.

This 1Z is in my Vanagon, and it's in a separate little box i the engine compartment

IS there a way to reprogram the relay/system so work at a higher temperature?

When I hooked up the VCDS, I. getting 01050 Glow Plug Monitoring- Intermittent (see pic)

Thanks all for your help in this matter!

Regards,
Steve

 

[Steve Addy]

Well there is a glow problem you need to track down and fix first, but if it's not below 40F you shouldn't need to have glow if the motor is in good shape and there's good battery and fuel present.

I can't tell you if that relay is correct, it is not a number I recognize and nor is it like the 180 relay used in the Mk3 and late B4 cars.

Steve

 

[tbones]

thanks Steve.

I'm still wondering where the glowplug relay gets the signal to turn on... is there a thermostatic sensor somewhere i shoulld ckeck?

thanks
Steve