Glow Plugs Don't Stay On

[Scottcore]

I recently replaced the head (as I'm sure many of you have) on my surf (93 SSR 2L-TE). It is going good, except the glowplugs don’t stay on long enough.

I checked all the glowplugs and none of them are open circuit, and they are getting the right amount of voltage, just for a very short period of time. I think there must be something wrong with the water sensor, or switch. But can’t find where either are located.

Could anyone advise if they have had a similar problem, or they know where that switch is. The damn engine bay is so crowded, can't see anything.

[Koi]

Hi
what are you testing the voltage with as the voltage to the plugs i think is 10.5 then 6.5 volts so unless using a multi meter the lower voltage will not be picked up by test lights etc.

From memory the glow plug relay is situated, off side upper wing

copied and pasted this from a previous post

To help cold starting diesel engines are equipped with a pre heating system, which comprimises of four glow plugs, a pre heat timer a dash mounted warning light, relays and timers.
The glow plugs are positioned directly in line with the incoming spray of diesel, when the plugs are energised the diesel passing over them is heated to its optimum combustion temperature allowing easier starting.
The length of the pre heating period is determined by the pre heating timer, which monitors the temperature of the engine via the water temperature sensors and alters the length of time accordingly.
Pre heating is started when the ignition is turned on, the light goes out on the dash but the plugs continue to heat for a bit longer, until the engine is started. If the engine is then not started within a certain time the power to the plugs is cut, preventing batttery drain and plug burnout.
After the engine has been started the plugs continue to heat the incoming diesel for a further period of time. This helps to improve cold fuel combustion whilst the engine is warming up, this improves cold running, which results in quieter, smoother running and reduced emmisions (the black smog). Again this length of time is measured by the water temp sensors allowing the plugs to pre heat the fuel until the required engine temperature is reached.

[Scottcore]

Hello Nigel,

Thanks for your reply. We tested the glowplugs themselves with a multi-meter and then with a mega. The glowplugs are fine.

The voltage drops we measured we correct to (10.5 for super glow, and 6.5 for normal). They just don't stay on for long at all, even when the engine is cold.

We have found the relay (it is over the top of the front left hand wheel up the back of the bonnet). But what I really need to find is eiter:
a) the sensor itself
b) the timer

Thanks again. If I can't work it out soon I might just take it to an auto electrician (although I hate someone else working on my car who's not me (or my old man))

Regards,
Scott

[wishbone]

Should help..

[NiftyNev]

The Glow Plugs rely on a signal from the Coolant Tenperature Sensor. If they are not staying on at the lower voltage until engine starts to warm up then check the sensor in the block. It's above the starter motor and under manifold.

Number 3 in the first pic here -

http://www.toyotasurf.asn.au/forum/v...ic.php?t=14158

Nev

[Scottcore]

Thanks guys,

That stuff is awesome. It looks like all I need to do is take the water pump off and I should be able to get to the sensor.

Wishbone, what manual did you get those images from. The manual I have (I can't remember what book it was from) is fairly useless. Mainly because it tries to cover all the different surf/4runner configurations.

Cheers again, I'll let you know how I go.

Regards,
Scott