92 Bighorn 3.1 TD timing advance

[dtreid]

Can anyone tell me if the 3.1TD is suppose to have a timing advance that is activated when the engine is started cold? If so, mine isn't working as it smokes like a freight train for a few minutes when cold.

[geeves]

How cold are we talking about? Where are you
we need a little more info

[dtreid]

I'm in Canada. I'm talking temps below 0 degrees C.

[guythorn]

Hi you should have a cold start button on your truck which you push in it will turn it shelf off when your truck has warmed up GUY

[dtreid]

Are you talking about the 'fast warm-up' button? Is that one suppose to advance the timing? I always thought it just raised the idle and closed the flapper door in the exhaust (which I removed).

[geeves]

For Canada I would of kept the exhaust flap although I don't believe it makes a huge difference.
Diesels do smoke when cold but a description of "like a freight train" suggests a problem.
The whole cold start system operates as one unit and the only real way to tell how its working is the length of time the glow plugs glow for. This should be close to 20 or 30 seconds at that temp and if you try and start before that and succeed a lot of smoke will occur. A bad glow plug could also be the fault but the engine would run rough for the first few minuites.
The 3.1 is indirect injection and will not start without glow plugs even in moderate temperatures.
If you want the workshop manual there is a copy for download in www.gmail.com Login as isuzunz pass 4jb1turbo
Download the attachments from the 11 ubs emails (120 meg) put them in a folder and unpack useing izark which is available on most freeware sites.

[dtreid]

I've also read that the glow plugs stay on for only 5sec if the engine is cold or 0.8sec if warm. Is this correct or should it be longer the colder things are?

[geeves]

True for the older 4jb1 engine but that will start in sub 0 temps even without glow plugs The 4jg2 has a more refined system

[dtreid]

What controls the glow plug on time? My glows never go for more than 5sec no matter how cold it is, so something must be knackered.

[mulover]

There is a little box in amongst it all with a timer in it for the glow plugs.

Even in the hardest southland nz frost (quite a few below zero) or in snow my glow plugs only come on for a couple of seconds.
I took off that cold start thing as it only closes a flap in the exhaust to hold the hot fumes in a liitle bit and increases the engine rev's a little.

Is it blue smoke or black??

If its blue smoke, then bare with me as i try to explain::
the tappet cover breather is connected to the air intake pipe which is connected to the turbo which is connected to the inlet manifold which is connected the motor. Isuzu's are well known for blowing a bit of oil out of the tappet cover breather and hense through the system, so when you park up there is a film of oil coating your inlet manifold.
Whilst your motor is sitting idle the oil runs into the combustion chamber and pools on top of the piston.
When you start the engine up the oil gets burnt off slowly and causes a nice cloud of blue smoke out the exhaust.

Hope that helps, this is what muy truck did before i put a catch can on. It still does it a little bit but no where near as bad.

[dtreid]

It's white smoke. I just think that if the timing was advanced a bit while cold it wouldn't do it. I've got quite a bit of experience with older VW diesels and it acts like they did on a cold start if the cold start/timing advance handle was not pulled out.

[dtreid]

It looks as though there is a plunger on the timing advance lever. It has 2 small coolant lines leading to it.
How is this system supposed to work?

[geeves]

There is a good description in the manual that you can get from the gmail account described in my earlier post. This apears to be the factory manual
Are you sure they are coolant not vacuum

[dtreid]

The manual that I have shows coolant lines to the CSD. Unfortunatly, there is no further description or way to test it.

[geeves]

There is a thorough test in the manual above but no good pictures. Unfortunately I have a 2.8 which is a sufficianatly different beast in this area to be unable to help more help more

[MattMU]

Mate there are a few things incorporated into the Isuzus for helping with the cold starts. A few already mentioned...

The preheat you sound familar with..the CWS has a wax pellet inside that nudges the throttle when cold but that is for idle compensation not timing.

The last is the VE pumps have a small diamond plate on the bottom connected to the injection plate inside and is rotated slightly to advance the timing the same principle as the breaker plate in an old dizzy.

This mechanism is controlled by the glow plug timer and uses fuel pressure from a solenoid in the fuel inlet to direct pressure to advance the timing when cold.

Matt.

[dtreid]

Where is this solenoid located on the fuel pump. There is the CSD on the lower outside of the pump, seemingly activated by coolant temp.

[MattMU]

Ahh ok, if you definately have the Wax pellet (coolant) type CSD then you dont have the solenoid one. The solenoid is in the return line above the fuel shut of solenoid on non-coolant CSD VE pumps.

Have a look at the link for the information you are looking for.

mebonty.monobasin.net/vepump.html

All the best

Matt.

[Roger]

My MU is 12/95 build. My rpm will drop automatically when certain conditions are met. Don't know what though.
I'll be sitting there and the idle will drop a little. I think it's a temp thing. I can have 2 different rpms @ 60kph in 4th- even though it's a small difference.
I think I've got what Matt said about timing advance.

[pig75]

Jan 8, 2009 11:33:07 GMT 11 Roger said:

I can have 2 different rpms @ 60kph in 4th- even though it's a small difference.

Not possible unless your clutch is slipping. The difference is your taco is giving a false reading some times