Bean Posted July 18, 2022 Report Share Posted July 18, 2022 Hi guys, I’ve been fighting my ‘86 505 TD sedan trying to get it running. Had a crazy ordeal replacing the filter head and spent a ridiculous amount of time finding and fixing air leaking into injection pump - cliff notes summary: Original primer diaphragm was ripped inthe glass jar filter head from a 504 (?) - So I replaced it with a NOS filter head with a used alloy canister and new filter. Loaded it up with Liqui-Moly Diesel Purge. Liqui-Moly Diesel Purge melted the NOS filter head diaphragm. Bought a replacement diaphragm and installed - still leaks air. Replaced all lines with clear vinyl to see where bubbles are coming in. Found cracked fitting - swapped all fittings from original filter head - still leaks air into fuel. Test with a different vacuum set up. Canister drain leaks air into fuel under vacuum - install new alloy canister - still leaks air. Wrecked new diaphragm testing trying to find the leak - too much pressure? Too much vacuum? Replaced diaphragm again with 2nd kit I bought - still leaks air. Try yet another vacuum test set up on the IP return to pull diesel through and still find bubbles entering. NOS filter head itself is the only thing I haven’t replaced - Moved all fittings and primer diaphragm to the old filter head and no leaks - finally! But now the heartbreaker - the Bosch VE pump is stuck - they normally start fully open, but once it fires it should immediately idle back, and it’s not doing that. It starts and goes full throttle immediately, but thankfully shuts off with the key. Not sure I can do anything to the pump while it’s installed to free it up, but if it doesn’t free up by itself I’ll need to swap in the resealed pump I had built years back. If anyone has some advice or some tips or hints to free up the VE Pump I’d appreciate it! If not I’ll be researching removing and installing the resealed injection pump I have, and praying the resealed on is fine after being stored so long. Rabin Quote Link to comment Share on other sites More sharing options...
Bean Posted July 19, 2022 Author Report Share Posted July 19, 2022 Picture of the final set up - used diesel in a Motive Power Fill to provide pressurized diesel to the filter head. Could then bleed the pump and lines easily. Mucked about with all sorts of contraptions using a vacuum pump, but likely did more harm than good! This was best by far: Line on right is from the power fill bottle with ~5psi. Did a whack more research and I think I can remove the pump top in situ to see if I can free up the governor assembly. Hoping to source the accel shaft and top cover seal locally, and if so I’ll give it a shot. ”While I’m at it” I’ll do the governor mod to the main spring, as well as some off boost tuning of the LDA - if I can fix the pump governor I may as well make it bit more peppy. @Goceand @SRDT @wadehilts - Not sure who else has Bosch VE experience, but any advice/tips on removal/Installing the IP from an xd3t would be appreciated in case I need to pull the pump or replace it. Rabin Quote Link to comment Share on other sites More sharing options...
Goce Posted July 21, 2022 Report Share Posted July 21, 2022 I've been there, my advice is get rid of the clear hoses and that clear fuel filter, run oem rubber fuel lines, and get a primer bulb. You may have better luck looking for a fuel priming bulb for a boat. One thing i've had happened is the bosch VE fuel pump to get gummed up from the bad quality of the diesel that is now. Best way to deal with that is to add some diesel fuel cleaner in the fuel, and push or pull start it, got a friend to tow you in 3rd or 2nd gear. It pushes the air out and fired up. After 2-3 trips on the high way the pumps clear up. You can see the primer bulbs on my 605, i have 2 of them one before the filter one after. Quote Link to comment Share on other sites More sharing options...
Bean Posted July 21, 2022 Author Report Share Posted July 21, 2022 Thanks Goce! Vinyl lines were for troubleshooting bubbles in fuel supply only, I have proper fuel lines. The plastic pre filter is a filter recommended on the Mercedes IDI forums. I did test and make sure it wasn’t the source of any issues, and I like the idea of having one but not married to it. I’ve removed the plastic filter while focusing on fixing the IP, and if it gets fixed then all lines will get return to proper fuel line. The orange plastic line is fuel grade fuel line between the injectors. I also want to update the stock filterhead to something more modern, and the bulb primer could be part of that, or an electric lift pump. I spent HOURS on returning the car yo that stock Purflux filterhead and it was a MAJOR pain in the ass to get it leak free. I like the idea of pulling the car in gear, but do you do this to start the car or to free the pump with fuel solenoid off? Car current starts great but goes WOT immediately, so it’d start quick and surge forward with full acceleration without the fuel solenoid disconnected. Rabin Quote Link to comment Share on other sites More sharing options...
Goce Posted July 21, 2022 Report Share Posted July 21, 2022 Sounds like gummed up pump, did you check the inlet mesh filter on the banjo bolt on the pump, check the outlet banjo bolt too it has a restrictor and can cause dieseling on engine it has too much fuel in the pump. Pulling it in gear has two purposes, saves the starter, battery and more importantly spins the engine at higher rpm that generates more heat and allows the diesel sistem cleaner to work. I've also had all 4 glow plugs fail at the same time and simulate air pocket in the fuel system, so it's worth checking them. Quote Link to comment Share on other sites More sharing options...
SRDT Posted July 22, 2022 Report Share Posted July 22, 2022 I don't know that much about Bosch pumps because Peugeot in it's infinite wisdom choose to fit Lucas pumps and nothing else on the 309 and 205 turbo diesel. Quote Link to comment Share on other sites More sharing options...
Bean Posted July 22, 2022 Author Report Share Posted July 22, 2022 I’ll check the mesh inlet and outlet filters, just for preventative maintenance, but the car starts up great - it just revs immediately once it fires. So I’m curious if you’re pull starting it, or pulling it to spin the IP? Only way I could pull it would be with ignition off so fuel cut solenoid didn’t have power. @SRDT - No worries, we never got any of the smaller cars, so had no idea they switched. The 405 had the ve pump so assumed all the little diesels did too. I’m fairly confident I’ll be able to fix it as long as it’s repairable. Definitely a lack of experience, but I’m learning quick and have a much better understanding of how it works and how to tune them. Rabin Quote Link to comment Share on other sites More sharing options...
SRDT Posted July 22, 2022 Report Share Posted July 22, 2022 The 405 and BX had either Bosch or Lucas pumps and it was the same for turbos with Garrett or KKK units. The 205/309 parts are not exactly the same so I guess they went with only one supplier. Quote Link to comment Share on other sites More sharing options...
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