Diesel RV Club, an FMCA Chapter

Technical => Engine Diagnostics => Topic started by: español on February 12, 2018, 01:55:27 PM

Title: does not start my cat 3126b
Post by: español on February 12, 2018, 01:55:27 PM
good afternoon and
   sorry for my english
I bought a boat with 2 cat engines 3126b 450 hp and loscar engine engines were disassembled, we recostruido cylinder heads, segments, injectors, turbos, etc.
now the motors are mounted and it is very difficult to start in cold.
all the injectors are recon, the diesel pressure is at 2 bar, and the oil pressure without start is about 85 bars and when it starts it is set at 125 bars at the minimum speed. I have changed valve and IAP sensor and the problem is the same, the engine turns well, the injectors are heard, it smokes but it does not start and when it starts it seems to have little power.
what problem can I have
Title: Re: does not start my cat 3126b
Post by: David.e.atherton on February 12, 2018, 04:52:35 PM
Hi, two things you will need to look at. First of all go to the rear of the engine and on the
rear of head there is what is called a injection return fuel regulator ( comes off rear head
on elbow than turns downward with fuel line connected on back.) Disconnect fuel hose and
put pan to catch any fuel, turn engine over you should have a good stream of fuel without
any air present. Engine may startup than put fuel line back on regulator. Next step you
Need power to your injectors to start engine. Pin 70 on the engine ECM J-1 facing down
on bottom ECM lower left corner red wire. Make sure you have power going to jnjectors.
Ask Dave Dave Atherton Retired Cat mechanic
Title: Re: does not start my cat 3126b
Post by: Ken Carpenter on February 15, 2018, 02:24:42 PM
elspanol replied:

The problem persists, the engine starts well in cold, but now when it warms up a bit, and I stop it, then it does not want to start, it turns to 25oce h0 revolutions when it starts, it smokes (it is injecting) but it can not start.