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doktordubbs

Noob with 505 STI TD

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Hi everyone. As of today I'm the proud owner of an 85 505 STI turbodiesel. I'm the second owner, the car is immaculate, and also apparently hasn't run since '97, when it was garaged after failing to start. Looking for any advice on how to take caution as I resurrect this beauty. I'm quite familiar with mechanical diesel engines, having owned so many W123s that I've lost count, a W201 (190d), as well as VW and Ford Diesels and currently drive a Chevy Cruze 2.5 TD. 

I know the basics (pull glow plugs and heavily lube cylinders, drain/replace all fluids and filters, new belts) but wanted to know if there was any Pug-specific advice from forum members. For example, are head gaskets an issue on these cars, especially if they have sat for extended periods like this one? 

I'm really excited to dive into this project. The car came with a new intercooler that hasn't been installed, maybe I'll get there, but for now I just want to get it up and running. Also it is missing its air filter box, any advice on a replacement (seems originals are impossible to find) would be appreciated.

Thanks in advance,

20191216_100250.jpg

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Apologies as the site would have gone offline shortly after you posted this!  

Car looks amazing, and I'm very glad it's fallen into an enthusiasts hands.  Have you made much progress?  Once we touch base on where you are now, I'd be happy to spit ball ideas.  

Talk soon!

Rabin

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It's no worries, just glad the site is still active at its new home!

Here is where I'm at - repaired a wiring loom that appeared to have been mouse-chewed. I now have electric in the whole car except for no taillights. Brake lights are working, but no taillights. All other electrical is ok so far. I'll be looking for further guidance on this once I have a running motor. 

As far as getting the car to start, here is the situation. Replaced questionable glow plugs with some new Monarks I had sitting around that happened to be the right part, and they are receiving power. I cleaned the fuel filter (it was actually in very good shape) and primed it. Can get the car to crank but not turn over. I cracked the lines at the injectors and after a few cranks I have fuel at the back two injectors. However, I see nothing coming from the front ones, even after a long time cranking to bleed air through. If there is something I'm missing on bleeding air, I'd appreciate some advice. My next move is going to be to remove the banjo fitting on the rotofilter (I think that's the housing name for the fuel filter) and top off the canister if it is low with some liqui moly diesel purge. I'll also run some down the fuel line if possible. My thinking is that perhaps the Bosch lifter pump has varnished up a bit after not running for 22 years, hence fuel at 2 injectors but none at the other two. I hope some diesel purge will loosen things up a bit in the pump. If there is a better approach here, I'm all ears. 

One question for the forum - the primer on the rotofilter has a very short stroke. It is a black button on top that feels spring loaded. Is there a way to release this and increase the travel and hence the primer's efficiency? I have had some like that in the past where you make a half turn for a fuller stroke on the prime, but this one doesn't seem to be made that way and I don't want to damage it by tinkering too much.

Thanks in advance - this will be a great 505 once I get it back on the road. I believe the color is "claret" with a gray leather interior that is pretty flawless. 

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I’m not experienced with diesels, but I just love them!

What have you done with the diesel in the tank?  I’d drain and fill with fresh with some diesel additive before you start with anything.

What I do to prime / test the system is to put one of those transfer / suction pumps on the injection pump return line.  I then draw diesel from this line which pulls diesel through the system.  If you use clear vinyl line between the injectors you can see them purge.  Not only does this draw fuel through the whole system - but it also ensures there’s no leaks in the primer assembly.  If it leaks it won’t feed the IP.

If that checks out I’d connect the fuel filter outlet to the diesel purge can so that you pull diesel purge through everything.  Let that sit in there for a day or so, then retry.

I assume you’ve got power to the fuel solenoid?  And fuel solenoid is working as it should?

Tail lights:  The absolute biggest issue with these cars are unsealed electrical connections, and bad grounds.  Inside the trunk you can access the grounding tree in the inner quarter panel.  Make sure all the connections are clean and wires in good shape.  Tail light circuit boards are also complete crap - you can sometimes “tighten” the plug on the board with a thin bit of plastic (like credit card thin) on the opposite side of the connections to make the board thicker.  Others have cut the ply entirely and soldered the wires to the board.  Connections on the board can also be crap as can the bulb sockets.   
 

There’s also grounding trees under the hood on either side of the rad, and another on the steering column under dash.  Consider ALL electrical connections suspect!  I usually clean and tighten spade connectors, and then use dielectric grease to seal and protect them going forward.

That should give a good start at least.

BTW:  Is this an auto or manual car?  

Rabin

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Unfortunately this is an automatic trans.

The PO's daughter drove the car out of fuel and then it sat, or so I was told. He was a collector with a ton of vehicles so this story seemed valid. The gauge didn't register anything when the ignition was on. As such, I just added 5 gallons of fresh diesel with a double dose of Stanadyne Diesel treatment. The gauge now registers slightly above 1/4 tank. I will drain the tank and clean it if nothing else seems to work.

I wasn't aware that there is a fuel solenoid on this vehicle. My assumption was that it would be an all mechanical fuel injection process. Can you give me a little more info on that and I'll check later tonight? 

Good call on using an external pump. I should be able to rig that up and run some tests plus move some fuel through the lines. 

re: the taillights. That reminds me of the older, mostly 8v Saabs of the 1980s. I have rewired a few sets of taillights on those for very similar issues. And yes, grounds, grounds, grounds! Most of mine appear to be in good shape but will get a once-over after basic things like a running engine have been achieved! 

Thanks for the tips, it's a great help and inspiration. 

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The beauty of diesel is it's oily nature really protects the fuel tank so it shouldn't need much at all to get sorted.  I'd put a pre-filter just before the main filter assembly just to catch any big stuff.

I used one of these hand pumps as it has quite high suction and can surface any leaks in the primer easily:

61j8fvWHOgL._SX466_.jpg

The fuel solenoid is here (6 cylinder but same pump really):

30189448.jpg

Might be worth checking to make sure it's working, and the ignition should be on and this activated before doing the suction trick.  Once you get some diesel purge into the injectors and the pump I'd let it sit a day before trying to get it to fire.

I've also used ether very very carefully just to get them to fire and so it's not cranking for so long.

Rabin

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I am getting power to the fuel solenoid, 11.5 volts which seems adequate. However, I put my hand on it and had my buddy turn the ignition, and I didn't feel anything click or clunk mechanically. Does that indicate failure of the solenoid? 

Rabin, can you or someone else on here provide me with an explanation of how the rotofilter works? I took the banjo fitting off, threaded the bolt back in, primed it, and got no fuel movement out of the bolt. It seems this should have at least produced a dribble of fuel. I'm wondering if I reassembled wrong after I initially removed it to check for blockage. Now there is no fuel at the two rear injectors either. 

I ordered what appears to be a 3-ring bound old shop manual from Ebay covering the 505TD, and it should arrive tonight. I hope it gives me a quick reference, and if it has anything really good I'll share photos with the forum.

Thanks,

Bill

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I'd disconnect and connect 12V manually to ensure the solenoid is working - there'll be silence when you do it and much easier to hear and feel.  Should be easy to unscrew and check that it's working for sure if there's still doubt.

As for the filter with primer pump - if the diaphragm is leaking then that pump won't work, and the injection pump won't get any fuel.  My 86' TD 5sp sedan is doing this now, and I have a new filter head to go on without the coolant heater in it which means I need to do some re-routing to clean lines up.  Car will never be a cold weather car so I'm just going to delete the heater circuit.

I've actually got some great reference material for diesels that JoE has sent me as I'm working on redoing the tech files section on the forum to make them easier to find and download.  Will send you some that will likely help you out as well, but having a printed copy is pretty nice too.

Rabin

 

 

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