crdi (how to adjust?)

[muÑoz]

how to adjust it?


is there any manual or book or websites that can teach me how to repair,adjust, and troubleshoot the crdi fuel sytem????

[duskylim]

how to adjust it?

is there any manual or book or websites that can teach me how to repair,adjust, and troubleshoot the crdi fuel sytem????

Dear muNoz:

A CRDI system is NOT a job for a weekend mechanic. There is NO WAY an average joe could service it without the proper equipment and training.

Most proprietary systems can't even be serviced by calibration shops unless they have specialist equipment and specs.

Tinkering with the settings of even ordinary older model in-line or distributor-type diesel injection systems shouldn't be done unless you have the right equipment, specs and have been trained to do so.

Leave the professional work up to the professionals. Go to a competent shop or to the dealer's service center.

Its generally a good idea to keep your hands off something you aren't trained to fix.

Regards,

Dusky Lim

[meledson]

the fuel is on a hi pressure level, pag nagalaw ng hindi expert, baka magkaroon ng leak/s.

[Hanren]

Do you have any concern, problem or issue with your CRDi-pwered vehicle? There are many experts here who can help you. Their advise or help might be even better and practical than reading any book or manual.

But of course, they can only give you what they can. A trained professional still needs to do the actual repair work.

[duskylim]

the fuel is on a hi pressure level, pag nagalaw ng hindi expert, baka magkaroon ng leak/s.

The pressures used in common-rail, direct-injection systems are only PART of the problem.

Those pressures can vary from 23,000 psig up to 29,000 psig in the latest systems.

Leakage is a minor issue - even for older, conventional systems.

The real issue is the crdi design itself and the complex electronic control needed to make it work right.

For example - some 5-7 year-old model Isuzu Trooper/Bighorns use an HEUI (hydraulically-actuated, electronically-controlled, unit-injector) design, from Caterpillar.

Here the injection pressure is raised using high-pressure oil from the engine's oil pump and gallery - which was modified to be able to supply/drive the injectors.

The control of the injection itself is via a computer control box with a proprietary interface (special wiring and connections).

You can't plug this thing into your home PC and expect the thing to allow you to change it's settings.

In fact, no one except authorized Isuzu dealerships actually have the equipment to do so.

The same thing generally goes for designs of Toyota and the other CRDi systems.

For argument's sake, let us suppose you were able to acquire the needed equipment.

Do you actually know how a modern diesel engine works?

While gasoline injection control is straightforward - that is, control of fuel supply to the engine means maintaining the correct injection pressure and just controlling the injector opening times - hence the ease of control of systems like MegaSquirt.

Diesel injection control is very different.

The system strives to but DOES NOT maintain constant injection pressures during the event.

There is more than a single injection event - there can be up to 8 separate injections for a single combustion cycle in modern CRDi engines - Robert Bosch systems.

The duration of a single, separate injection event is measured in milliseconds (thousands of a second).

High-speed, high-voltage (for rapid actuation) solenoids or even direct-acting stacked LC's (liquid crystals) are used to control the injector - because of this the injector often has a separate electrical power supply.

The fuel quantities delivered per event vary.

Playing around with the controls also VOIDS the warranty.

Good Luck.

Dusky Lim

[niky]

The multiple injection events and the ultra-precise fuel metering and timing required for each is one reason you can't make a Megasquirt work for CRDis. In fact, so far as I know, there are no commercial standalones available for CRDis yet... just piggybacks and programmers... because it requires a very powerful processor to run a CRDi engine, and the piggybacks and programmers merely adjust the function of the stock ECU instead of replacing it.

There are huge problems with touching a CRDi system without the proper tools. On some systems, if you replace the injectors, you actually have to reprogram the ECU for each new injector, as they are individually calibrated.

-

The best you can do with a CRDi is learn to spot potential problems... possibly learn how to clean the EGR, tighten hose clamps, etcetera... but to actually touch the fuel system? Forget about it.

[muÑoz]

we have here a calibration shop..
we can repair all kinds of diesel injection pumps...
but now,the companies made an electronic injection pumps and
our problem here is how to repair the CRDi..
we have some customers bring their pick ups like hilux CRDi and the rpm doesn't up.
it travels only 50kph max,then we try to get the idle throttle to its max for how many times then we test it again,then it become faster, 120kph.


anybody who can explain me why and how is it happened?


thanks

[robin_micmac]

The pressures used in common-rail, direct-injection systems are only PART of the problem.


There is more than a single injection event - there can be up to 8 separate injections for a single combustion cycle in modern CRDi engines - Robert Bosch systems.




Dusky Lim

this what they call pilot and main injections. this was impossible to do during the era of mechaincal injection systems and was only possible with the help of electronics that control the injectors. this improves diesel combustion by avoiding diesel knock and this is also the reason why crdi engines tend to be more silent than the mechanical ones as the pilot prepares the combustion chamber for the main injection and hence the sudden rise in pressure is more controlled.
i agree with dusky, crdi should be left alone for the trained expert with the proper equipment. its a very complicated system. you cant adjust it as the mapping on the engine ECU are fixed.