28/07/2021
I got a call a week ago today from a customer having problems with a 3126B in a Hartl crusher. I told them i couldn't attend till today. They told me the issues they were having with the engine, and what the fitter had done, New Turbo, Heui pump, fuel regulator and various sensors. The same day a post appears on the FB Plant chat asking for advice.
"After a bit of help
Got a 3126b cat engine in a crusher.
Customer has fitted new turbo and heui pump.Intercooler has been cleaned and inspected.
When engine is under load,it drops boost pressure to a minus value and derates to 1800 rpm and black smokes.
Changed boost sensor,checked wiring.
Changed fuel regulator,fuel system cleaned.
Lots of s**t in tank pryor to cleaning
Anybody come across a problem like this ????
Couple of things to the lads who generously try to help these fitters (me included) don't believe any of it.
The air filter box cover was strapped on with a ratchet strap. the air filters both inner & outer wasn't sealing, the Outer filter centre had been cut away to fit the inner inside it. The cover had previously been through the crusher box and been made to fit with the strap.
On running the engine up till is defaulted to its fu**ed state as you see from the graph everything i was monitoring was fine.
I had already checked the Atmop Sensor, fuel etc. cyl cutout boost sensor was all ok.
So after 3 minutes of loading watching the boost sat at the side. The Boost drops off, the ECM sees the drop in speed, and trys to accommodate by increasing the Huei current, the Huei desired & Actual goes up.
By this time the Engine is chocking itself to death, screaming "For f***s sake do something Nick"
I checked the boost was at -3, I dis-connected to see my abnormal signal in ET, which is expected. Re-connect the sensor to read -3 again. Still screaming like a Yorkshire Ripper Victim. the Hose from the Turbo to After Cooler was blown up like a Football. The Hose from the After Cooler to Inlet was getting as thin as a racing snake.
Took the Inlet hose off the engine, and it took a deep breath of fresh air, the boost was now reading 1 psi (normal)
On inspecting the boost hoses the one from the Tubo to the After cooler had been recently replaced, with the wrong hose, they had to use part of the old hose to make the diameter smaller. The old hose had split, probably due to it blowing up too much, The Hose from the After cooler to Inlet was full of s**t & Oil. the turbo passing oil only due to the fact it wasn't getting rid of the volume/pressure of air. On putting the Camera down the hose, It was full off oil.
Good job it was starved of air, had it been clear it would have run on the oil in the cooler and we know what happens then.
The Customers fitter is going to remove the cooler and send it away for cleaning inside & out. They need a new air box & filters, New after cooler hoses to replace to made up ones that don't fit.
There is something in the After cooler which when it boost blocks what flow it had.
It could be a rag a bag, glove thats been left in the pipe, but it be the old hose working as a valve as it wasnt right on the pipe and more inside the makeshift hose. The After Cooler never been cleaned, Air filters & box fu**ed, Full of oil,
It requires a good clean out.
