Big update for today. Last night w/ help from my dad, got the fuel system tuned up and re-set the rack/governor. These adjustments were last touched just around August 2011 and done rather hurriedly so we decided to check and adjust under the valve cover.
First off was to replace the faulty fuel pressure gauge. After replacing that, we found that fuel pressure was a little lower than expected. We did a MUCH NEEDED filter change of both primary and secondary fuel filters and got fuel pressure back where it belongs. It appears the primary filter had filled completely with crap from the fuel tank (again).
Next we pulled out the book and started adjusting idle speed, governor gap, and then set each injector on the rack. Turns out that I had the governor gap WAY out of adjustment from the trip down to the burn (me attempting to get more fuel for hill climbs when issue was actually related more to fuel supply issues). Once this was adjusted, we set all the injectors per the book using dad’s ‘magic hands’ to fine tune the adjustments.
There appears to be a very tight tolerance on the shutdown arm that I would eventually like to address (full speed/full rack the shutdown arm touches the rod heading into the valve cover and COULD limit fuel). A little bench grinding on the arm or sourcing some rebuild parts for this could address any concerns. Either way, the final adjustment seems to be much better and the only glaring flaw in my rack setup was one injector slightly off adjustment and I either left off or knocked off the rack return spring (in case of failure, causes rack to default to no fuel position, versus floating and overspeeding engine). This spring being disconnected wasn’t helping the loping idle issue. We also installed some missing washers/clips on the control rod on the governor end.
Idle appears proper now, and the last bit to address is getting a type of buffer screw attached for enable/disable the jake brakes. The stock 8v71 one that I have is too large to fit in the engine compartment (6-71 one is much shorter).
Hopefully between the fuel tank cleaning, the new filters, the adjusted governor, and the re-running of the rack; I will have a little more power to push down the road. The long term goal is to fit a proper turbo and potentially aftercool. This will require modification of the exhaust system, intake, and a bunch of plumbing.
In other news, I bypassed a bunch of brake system stuff that was a source of leaks and was only used for transit service. Fortunately the plumbing didn’t require anything other than capping one line, and moving another directly to the foot valve. Now system air pressure holds for many hours (though there is still a leak or two in various places). The suspension system needs the new leveling valves installed however I likely won’t get to those before departing.