My '84 pup has just had the top end rebuilt, head recast after blown gasket and cracked head, new valves, injectors rebuilt, the injector pump itself was rebuilt about 9000 mi ago, and a new fuel filter & housing, but it won't start. I'm assuming the pump's ok, having been rebuilt so recently, but there's very little pressure at the fuel line that connects to the injectors. I'm thinking it has to do with the fuel cutoff switch on the injector pump. My question is this, where can I get a new cutoff switch? I'd like to try that before I send out the pump to be rebuilt again.

I'm not familiar with the Isuzu cutoff switch, just going by memory of my old Land Rover diesel - Could you remove the fuel cut off switch and try? You'd probably have to stop the motor by putting it in gear and letting the clutch out with the brakes on. Possible test without buying a new switch.

If it's an electrical switch like I'm familiar with, have you verified it's getting voltage?

Again, I'm not familiar with that motor, just throwing ideas out hoping they might be helpful.

Paul

Have you checked with Jerry Lemond to see if he has one?
He can still get at lot of new Isuzu diesel parts when we can't find them. I was just at his place earler this week and got some really nice stuff for my Diesel I Mark.
In case you don't know, Jerry used to teach the US Isuzu Mechanics how to work on them. So if anyopne knows Isuzu, he does.
His E Mail is jlemond@Bellsouth.net

Curtis

I guess you already checked the fuel supply
Always go for the cheaper fix first.
A plugged fuel filter will make low pressure too. I always put a lift pump in the equation to troubleshoot fuel delivery issues. Add the electric pump back at the tank that way you know you have good fuel supply out of the filter(s)
Google "Facet pump" I use the low pressure (3-5 psi) pump so I don't add stress to the injector pump. Once the extra pump is in the circuit you can eliminate all air leaks and clogs