[Corsa B 1993-2000] turbo diesel engine tuning

[corsakid]

I have a 2000 w reg corsa b 1.5 turbo diesel i dont know if its the izuzu engine or not it says diesel on the top and what performance upgrades can i do to it

[Hardcore]

All the diesel engines in the Corsa B were Isuzu.

There's a few things you can do for more power.

Straight through exhaust system
Remove cat & centre box. If you have money, get a turbo back exhaust with a larger diameter pipe.

Front mount intercooler
Keeps the intake temps down so less chance of melting engine on bigger power. Needed for anything over 1.1Bar of boost and / or 95bhp.

White ring mod
Removes the white ring on the diesel pump boost plunger. This means when the car comes onto boost, more fuel is delivered and the power comes in a lot stronger

Max fuel screw adjustment
On the diesel pump, the anti tamper cap gets removed so you can access the max fuel screw. Adjust it to inject more fuel into the engine. You might need to adjust the cold and hot idle control screws afterwards though. Too much fuel will get too much black smoke as well so be weary. Too low fuel means it will run lean on higher revs and cause overheating.

Increase the boost
With the fuel mods above, increasing the boost with a manual boost controller / bleed valve will give more power as well.
1.6bar seems the max on this engine, but the turbo and head gasket reliability might be dodgy at this pressure. 1.1bar is safe.

There's more you can do. Bigger turbos, different gearbox ect.

If you have a front mount intercooler. exhaust mods and the boost and fuel done you should see around 105bhp or more @ 1.6bar.
Without the front mount intercooler and without the exhaust mods and just fuel and boost done you should see around 90-95bhp @ 1.1bar.

Results vary on health of the engine

[Rob]

use the search button

[DieselPower]

Max fuel screw adjustment
On the diesel pump, the anti tamper cap gets removed so you can access the max fuel screw. Adjust it to inject more fuel into the engine. You might need to adjust the cold and hot idle control screws afterwards though.
Results vary on health of the engine

I am not sure there is such thing as hot and cold fuel adjustment. I discovered that the 700 rpm on cold engine is due to the glow plugs working the first 3-4 minutes. When they turn off, the rpms go to 910.

[DieselPower]

I have read too, that this engine is easily tunable, with virtually no cost. BUT, the thing with the 1.5 TD engine is, in factory stock form, the coolant temperature rises above 100 degrees after only 3-5 minutes of trashing, after that you should raise your foot off the gas pedal. Yes, the engine can easily be tuned to 95hp with no money involved, but can you really use that power? I am afraid not, you will melt the engine.

[Rob]

I am not sure there is such thing as hot and cold fuel adjustment. I discovered that the 700 rpm on cold engine is due to the glow plugs working the first 3-4 minutes. When they turn off, the rpms go to 910.

glow plugs work for a max of 20 seconds then turn off. they are only there to help start a diesel not to run it. id suggest your cold start enrihment on the pump isnt working.

I have read too, that this engine is easily tunable, with virtually no cost. BUT, the thing with the 1.5 TD engine is, in factory stock form, the coolant temperature rises above 100 degrees after only 3-5 minutes of trashing, after that you should raise your foot off the gas pedal. Yes, the engine can easily be tuned to 95hp with no money involved, but can you really use that power? I am afraid not, you will melt the engine.

they dont melt. ive set 4 of these up for friends, all making 90+bhp. yes they get hot on the guage, but they cool down pretty quick. engine coolant wont boil until 130 deg as its pressurised, it takes around 300 deg to melt an engine wilst running. and the reason they get hit is that the turbo is behind the rad so the air is heated at both sides of the rad. - fit bigger fans.

[DieselPower]

glow plugs work for a max of 20 seconds then turn off. they are only there to help start a diesel not to run it. id suggest your cold start enrihment on the pump isnt working.

I am about 50% sure that the glow plugs are working the first 4-5 minutes. I plugged in digital voltmeter at the lighter socket, so I can monitor the voltage all the time. After the cold start and for the first few minutes the voltage is much lower than desired 13.8V. It sits at 12.4V at idle, or varies between 11.7 and 13.3 during driving. After the plugs switch off (you can hear the clicking sound), the voltage immediately changes to 13.8V. There is only one thing that can pull out that much current. It happens every time when the engine is cold.

Also the sound of click is exactly like the sound of the glow plugs shutting off. This wouldn't be the first engine that uses the glow plugs to support the cold engine.


I will be 100% sure after I make the direct test: ampere-meter on the glow plug after engine start, to see if they are working or not.



About the engine melting or not, it was a figure of speech. These engines are running hot when trashed, so I would guess its not a good idea to use that extra power on high temperature. But, I'v never done it, so I wouldn't know. You have experience on this subject so your word is more valid here.

[Hardcore]

I know the click you mean, but not sure what it is personally.

I'm quite sure though that on these old diesels the glow plugs are only on for a few seconds before starting the car. I know modern diesels they stay on a bit longer.
I could be wrong though

They deffo do have a hot and cold idle screw. I seen a few threads from people tuning them where they were adjusted after the max fuel screw was turned up as it messed up the idle fueling as well.

When i had mines, no matter how hard i drove it the temp gauge never went over half way. I'd even done 114mph in 5th at approx 5000rpm for a good 20 seconds before and it still didn't rise. Scotland is quite cold though.

Any more boost than 1.1bar of pressure then the extra heat generated will cause power loss.
I seen people drive them at 1.9bar before, with no intercooler and the engine still runs ok years later.

The reason they overheat is at high boost pressures the diesel pump can't provide enough fuel at higher revs so it runs really lean and hot.
As long as the boost isn't up too much without an intercooler and there's enough fuel and don't red line them every gear change it should be fine.

[Rob]

I am about 50% sure that the glow plugs are working the first 4-5 minutes. I plugged in digital voltmeter at the lighter socket, so I can monitor the voltage all the time. After the cold start and for the first few minutes the voltage is much lower than desired 13.8V. It sits at 12.4V at idle, or varies between 11.7 and 13.3 during driving. After the plugs switch off (you can hear the clicking sound), the voltage immediately changes to 13.8V. There is only one thing that can pull out that much current. It happens every time when the engine is cold.
the click is the glow plug timer (a relay) it times out after a set time dependant on the temp reading from the engine temp sensor. they do draw a decent amount of current. if i was you id be checking the temp sensor. sounds like its reading over cold.
Also the sound of click is exactly like the sound of the glow plugs shutting off. This wouldn't be the first engine that uses the glow plugs to support the cold engine.


I will be 100% sure after I make the direct test: ampere-meter on the glow plug after engine start, to see if they are working or not.



About the engine melting or not, it was a figure of speech. These engines are running hot when trashed, so I would guess its not a good idea to use that extra power on high temperature. But, I'v never done it, so I wouldn't know. You have experience on this subject so your word is more valid here.

as said by nhardcore they only run hot if there is a fault.

[DieselPower]

Hardcore,

In cold winter days like these, I can drive at maximum speed (170kmh) for 20 minutes and temperature of the coolant sits at 95. (92 is normal). But in summer when the temperature gets high 30's, or even past 40 degrees centigrade, you can only go for 5 minutes before the coolant temperature rises from 92 to 100. I don't want the car to run at 100+ degrees, although, maybe 100 degrees is not that bad...who knows.