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wheel loader 988f series II Not starting

abedsunna

Well-Known Member
Joined
Sep 13, 2020
Messages
90
Location
Oman
dear friends

i have wheel loader 988f cranking but not running , power to injectors not reach , fuel is reaching good

any suggest where to look and where i can find the crank sensor and how to check it
ecu have power 24 volts in 3 places for input socket
 

Nige

Senior Member
Joined
Jun 22, 2011
Messages
29,377
Location
G..G..G..Granville.........!! Fetch your cloth.
This machine has a HEUI fuel injection system in the engine. It depends on hydraulic pressure to activate the injectors. Leaks in the hydraulkic system (pump or injectors) will cause a no start situation. The electronic system will not activate until sufficient hydraulic pressure (about 3,000psi) is produced during cranking.

Follow the tubes from the high pressure oil pump to the cylinder heads. Observe where the tubes connect into the cylinder heads. If you then look at the opposite end of the cylinder head in the same location you should find a blank plug. Install a 5000psi gauge on one of the cylinder heads, crank the engine on the starter and record the pressure.

Also you should be aware that these engines are very sensitive to cranking speed. Good batteries and starter motor are very important. A cranking speed of 150 RPM on the starter is an absolute minimum, over 165 RPM is preferred. With a cranking speed around or below 150 RPM it is highly unlikely that the engine will start even with the injection system in perfect condition.
 

abedsunna

Well-Known Member
Joined
Sep 13, 2020
Messages
90
Location
Oman
This machine has a HEUI fuel injection system in the engine. It depends on hydraulic pressure to activate the injectors. Leaks in the hydraulkic system (pump or injectors) will cause a no start situation. The electronic system will not activate until sufficient hydraulic pressure (about 3,000psi) is produced during cranking.

Follow the tubes from the high pressure oil pump to the cylinder heads. Observe where the tubes connect into the cylinder heads. If you then look at the opposite end of the cylinder head in the same location you should find a blank plug. Install a 5000psi gauge on one of the cylinder heads, crank the engine on the starter and record the pressure.

Also you should be aware that these engines are very sensitive to cranking speed. Good batteries and starter motor are very important. A cranking speed of 150 RPM on the starter is an absolute minimum, over 165 RPM is preferred. With a cranking speed around or below 150 RPM it is highly unlikely that the engine will start even with the injection system in perfect condition.
thank you dear

can you also drop the electric schematic to my email please to check the power
and also the batteries wiring are not in place so how to connect the batteries please
abdulla_sunna@hotmail.com

i have + and - in both sides with 4 batteries
 

Nige

Senior Member
Joined
Jun 22, 2011
Messages
29,377
Location
G..G..G..Granville.........!! Fetch your cloth.
I need a machine Serial Number so as to locate the correct schematic.

Here is the battery wiring diagram. It needs 4 batteries in good condition plus a starter motor in good condition to get the correct cranking speed.
 

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