6shooter
Member
Hey guys, got a question on an IT28B I went out on the other day that's been racking my brain. 3204 engine in it, can't remember s/n prefix off hand so sorry for that. Customer stopped it the night before, (shutdown is by pulling up on the governor pedal in the cab) and the next day it wouldn't start. Pedal felt light in the cab when I got there, like it wasn't pushing any linkage around in the governor/fuel pump and it may have been stuck on "no fuel" position. I tested fuel pressure going into the filter inlet on the pump, spec is 6 psi while cranking, I had 9-11 psi, and I could hit 20's plus when using the hand primer. I held the linkage both on low idle and high idle while cranking over with all 4 injector lines pretty much opened up on the fuel pump and not so much as a few drops came out after 6-10 seconds and longer of cranking. I know the pump has the potential to get fuel through it, because with the 4 injector lines opened and using the hand primer pump, I got flow out of all 4 of the fittings after a few pumps. I know these older units use engine oil pressure for something inside the governor, but I wasn't clear on exactly what even after reading up on it in systems op. The few questions I have are 1) the manual specifies to bleed air by hand priming with the pedal in the fuel off position, so should I have been getting fuel out of all the injector line fittings while hand priming with the linkage in fuel off position? 2) With the governor linkage in "fuel on" while hand priming, shouldn't I have been getting fuel out of whatever cylinder line was "open" depending on engine position, not all 4? It didn't seem to matter, fuel off, fuel on, low idle position or high, when hand priming, all 4 injector line fittings were dumping fuel out. I checked the drive gear on the pump, it wasn't spun/spinning on the pump shaft that I could tell without disassembling it, so I have to assume it's turning with the engine. I have adequate fuel pressure in the low pressure system, nothing is clogged as far as fuel lines to the pump inlet, and the pump is turning. Barring an engine oil pressure issue not doing whatever it's supposed to do (I did have flow of oil when removing the governor linkage side cover and turning the engine over), there's really nothing else it could be but the pump internally, right?
Also, the customer was asking me this, and I had no idea. Why are there fuel passages in the injector line bulkhead fittings at the valve cover that are drilled to empty into a channel that runs along the valve cover base just under the gasket and just ends at the rear of the engine? Apparently he had a valve cover gasket not seal before and he said he had fuel just running out the back of the valve cover down the engine block and had to replace the gasket.
Sorry for the long post, I'm a "youngin" and get very little time on these older engines, so the complicated governor linkages, flyweights, governor oil pressure systems throw me for a loop sometimes. Any help is greatly appreciated!
Also, the customer was asking me this, and I had no idea. Why are there fuel passages in the injector line bulkhead fittings at the valve cover that are drilled to empty into a channel that runs along the valve cover base just under the gasket and just ends at the rear of the engine? Apparently he had a valve cover gasket not seal before and he said he had fuel just running out the back of the valve cover down the engine block and had to replace the gasket.
Sorry for the long post, I'm a "youngin" and get very little time on these older engines, so the complicated governor linkages, flyweights, governor oil pressure systems throw me for a loop sometimes. Any help is greatly appreciated!
