I'm having a hell of a time with the throttle and idle on my 3.0L turbodiesel engine (617.016 - apparently a marine engine? All the ancillaries are car stuff)

Quick overview of the car:
240D chassis
4-speed manual transmission
3.0L turbodiesel engine swap
Twin tank WVO conversion

I just replaced the vacuum booster. The front brakes are due for new pads. Both secondary fuel filters have been done since the problems began. All linkage rods have been relubed since the problems as well. On the table for tomorrow is to try and find/replace the primary filter!

Symptoms:
- Car does not idle
---- Car sometimes shuts down, other times experiences engine runaway (without moving the throttle linkage in either case, it will do it at the same setting)
- Loss of power
- Throttle linkage is sticking in an intermediate position
----- Partial disassembly and testing points to the spring end on the idle set screw? (Linkage does not stick if the set screw is backed out sufficiently, but car will not idle at all at that point).

- Front brake warning light stays on intermittently after foot is removed from brake (may be unrelated)

Brief history: The car was running fine until the other day. I had driven a couple hundred miles on veggie, and I switched over to diesel prior to shutdown (since I like being able to start the car again...). The engine immediately bogged and died. I had to manually idle the engine via the throttle to keep it running, but only on diesel - it ran fine on WVO. In order to try and keep the car from bogging and dying in traffic (I was near San Fransisco), I fussed a little with the idle adjustment screw. This is when I discovered the throttle stick issue, as a setting that would work for idle would suddenly runaway on me and other times bog and die. I relubricated the linkage at this point, and tracked the 'stick' issue (the actual linkage will hang up about halfway unless you snap the throttle all the way open and let it rebound shut) to the idle adjustment screw. I tried to work some lubricant into the spring-loaded tip, but this did not alleviate the problem. This has spread the inability to idle to the WVO as well, now. One possibly unrelated point I noticed when replacing the fuel filter is that the fuel intake line is plumbed into the banjo fitting ontop of the filter assembly - does this dump into the filter, or do I need to reroute the lines to the stock filter inlet?

Any help would be appreciated! I'm having the problems on either fuel, though the car is more composed running on vegetable oil. I'm at a total loss for what could be causing this/these issues. The car is a complete frankenstein, so alot of local shops here in central CA probably won't touch it.

bump/update

I'm totally lost on this... noone has any ideas/suggestions?

Turns out there is no primary filter on my car anymore! The diesel filter has been completely bypassed by the looks of it, and instead the system has been rerouted to push everything through the secondary filter that I thought was WVO only. Anybody know if Pollack valves can take pressure as well as vacuum? I'm wondering if I should replumb the system at this point...

Pollack valves are known to fail. Check to see if veg is making it into the diesel tank and vica-versa. I would also liike for clogged lines to the IP, and check for cloggen injectors since your filtration system has been hacked.

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RRGrassi


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