glow plug light problems

hello i own a 1990 model 2.4td hiace and i have a problem with the glow plug light
when you turn the car on the glow plug light comes on then goes off but when you start it a relay clicks then it comes back on and is very sluggish any help would be great thanks

Could be one of two problems that I have come across.

1 There is a sensor underneath the air manifold that controls the glow-plug initial power-up. When the engine is warm the time on is minimal i.e. the dash light comes on briefly. Check with a test bulb - earth to the engine and pos to the glow plug tip - How long - if any does the plug take power?

2 The relay has packed up!

Sounds like your glow plugs aint cutting the mustard!!If the engine is sluggish for a while-- does it improve when the temp creeps up?

Initially you need to confirm power to the glow plug tips.

some times it runs fine but when that light is on its sluggish

i disconnected the 2 relays and the glow plug rail and the light still comes on what else controls this light it only runs bad when the light is on

Sounds like an earthing problem if the light is still coming on. If its sluggish there is no power and heat at the glow plugs.

Have you checked if there is power to the rail and for how long ?10-20 secs?

Are the glow plugs intact - sometimes the tips erode.

does any one have a workshop manual the lifgt stays on constantly it may mean something

I'd guess that the light staying on while the engine is running likely means some system is not functioning properly. If the vehicle is starting the glow plugs are doing their job. This is just a guess though.

You might want to try and post the same question here:
http://www.toyotadiesel.com/forums/
There are some fairly experienced mechanics on that site.

Good luck and keep up posted when you figure this out.

it seems not to be selecting 1st you have to put it in low then move it up to drive this is only when the glow light is on does this light do anything else