S54B32
New Member
Hi guys,
Wondering if anyone can shed some light on this situation on a mates boat.
Twin KAD32's - during a trip he noticed the port engine RPM had dropped to 2900-3000RPM under WOT, with the starboard at 3600RPM. The RPM starts to differ at about 2000-2500RPM, hard to tell exactly.
He has switches fitted that lets him manually switch the superchargers on and off, mostly the same behavior with it on or off on the port engine (nnce already at WOT), with revs climbing ever so slightly (not 100%) with it off, maybe 50RPM (I'm think as it's reducing a bit of load) and the turbo is then able to make the boost anyway?? The switches definitely work as huge difference getting on the plane with them off.
He's cleaned/replaced every fuel filter he can see and also tried running the engine on the other tank - no change
He's checked the turbo for play and there's virtually none and it spins freely, he's going to check it against the other side to be sure, but we're 99% the turbo is fine.
To me it seems like a fuel flow issue, and without a wastegate, I'm thinking the boost is only really limited by the fuel input, so a fuel issue would appear as low boost too, thoughts?
He's checked the diaphragm on the injection pump and it all appears fine (think it's called a smoke valve on these), I was almost sure this would be broken thus limiting the fuel flow.
He did find that that the lift pump was broken, when he manually pumped it nothing happened and when he pulled the old one out, it literally fell to pieces, replaced it and the problem is exactly the same.
We're now thinking of swapping the injection pumps from side to side, to isolate the issue.
Has anyone had anything similar and is there anything that usually goes wrong in these injection pumps?
Much appreciated,
James
Wondering if anyone can shed some light on this situation on a mates boat.
Twin KAD32's - during a trip he noticed the port engine RPM had dropped to 2900-3000RPM under WOT, with the starboard at 3600RPM. The RPM starts to differ at about 2000-2500RPM, hard to tell exactly.
He has switches fitted that lets him manually switch the superchargers on and off, mostly the same behavior with it on or off on the port engine (nnce already at WOT), with revs climbing ever so slightly (not 100%) with it off, maybe 50RPM (I'm think as it's reducing a bit of load) and the turbo is then able to make the boost anyway?? The switches definitely work as huge difference getting on the plane with them off.
He's cleaned/replaced every fuel filter he can see and also tried running the engine on the other tank - no change
He's checked the turbo for play and there's virtually none and it spins freely, he's going to check it against the other side to be sure, but we're 99% the turbo is fine.
To me it seems like a fuel flow issue, and without a wastegate, I'm thinking the boost is only really limited by the fuel input, so a fuel issue would appear as low boost too, thoughts?
He's checked the diaphragm on the injection pump and it all appears fine (think it's called a smoke valve on these), I was almost sure this would be broken thus limiting the fuel flow.
He did find that that the lift pump was broken, when he manually pumped it nothing happened and when he pulled the old one out, it literally fell to pieces, replaced it and the problem is exactly the same.
We're now thinking of swapping the injection pumps from side to side, to isolate the issue.
Has anyone had anything similar and is there anything that usually goes wrong in these injection pumps?
Much appreciated,
James
