This might be a little off-topic, but do you have any idea how I can find the cause of the engine stalling after 5 seconds, or ideally, narrow it down before buying it? The engine currently has about 10,000 km on it.

 

Because there is an aftermarket ecu, you may be limited with what the ecu diagnostic functions can tell.

That means you may have to run through a series of tests until you find the problem, or a series of problems.

This could take significant shop time and likely assistance from a shop familiar with the car.

Despite it being a low KM motor, perhaps start with a compression test. Someone might have overreved the motor and blown out some seals.

Check the fuel pressure.

Check if you care getting spark.

Check if there are any restrictions on air intake.

Enquire about the history of the fuel. How old is it? Perhaps replace the fuel.

Check if the TPS and MAP sensors are in spec.

Check coninuity of the various other sensor or try replacing them one by one

Etc.

 

Sooo, the day finally came and i got to see the car.
Biggest surprise: The car started on the second try. First try was the starter trying for 3-4 seconds without success.
Almost as big a s a surprise: The Garage was soaking wet, holy hell. See the moisture buildup on the engine in the videos.
Cables below the passenger floor mat are a crazy mess. Engine wiring harness and passenger room harness both seemed to be cut up as well as additional cables hanging around. When moving the Adaptronic ECU around the extra gauges would sometimes go out, then on again. White smoke cloud erupted from the exhaust at the start, Idle at 1300-1400 rpm for the first 5 minutes was mostly smooth a small pop like you hear in the video every 5 to 7 seconds or so. After that idle at 2000rpm, a small pop every 10-15 seconds.
It has 5 extra gauges and 4 of them read read reasonable values (boost, temp, etc) but the lambda value shows an error.

Successful start: https://streamable.com/hwgdvs
Idle 2-3 mins after start: https://streamable.com/7mcfez
Small revs, but also sounded and revved clean till 4.500 rpm: https://streamable.com/wj5ec6
Even did a 2 minutes drive on private ground, not faster than 30 km/h since the car has as seasonal plate. Everything seemed smooth.
Does this sound well to you guys?

Fenders and side skirts looked very good and rust free, as well as anything i could see underneath. Some beginning rust seems to surface behind in the upper area of the boot, as well as on the spots where the original mirrors were mounted. Paintjob is pretty bad in general but i hate the grey so it would have gone sooner or later anyway.

Oil leakage under the car (engine) but it seemed to be clear two stroke oil on the floor, probably coming from the hose of the extra oil tank. Everything below the engine was covered in this oily grease, as seen here but the engine was rather dry.
He has a guy who wanted to do the electronics this winter but then the owner decided he rather wanted to sell it. I asked him to check on the guy if he is still in hold of the harness and still willing to do it. Let's see how the following week play out.
The wiring situation is worse than i thought and the moisture is also a concern. Car was a little bit wet at the inside roof part in front of the boot, so above the "rear seats".

 

Jesus, did they pull that thing out of the Atlantic, or what? I've never seen so much standing water in an engine bay of a car that wasn't involved in a flood.

That engine sounds better than mine did when I got it. Which is also the only one I've ever heard, so I can't help there. And, as Chris @ Banzai just told me last week as he tore my old one down, I had an apex seal clean broken in half... so it would probably be a pretty shitty barometer to compare to anyhow. The thought of detonation always worried me, but I've heard that those little 'pops' at idle are normal. I've also heard that they're not.

The build-up of crud is normal -- inasmuch as my car as a comparison is 'normal' anyways. 30 years of leaking and burning fluids and a tight engine bay that's impossible to clean yields a nice layer of goo on everything. My power steering rack had so much crud built-up on it that I had to literally scrape it off and I was truly surprised that the pinion gear housing was painted silver. Here I thought people just painted it that way when doing the refurbs because it looked nice... and then I found out it was silver all along.

I did get my Wiring Specialties harness last week. It looks great. They claim to use OEM connectors and while I cannot verify that for certain, they are definitely a higher-quality than what I've gotten in pigtails before. The labeling on every line is extremely helpful -- I wish the OEM one had that. Everything appear pinned well (can't verify correctness for a while yet) and the loom and shrinking was all neatly done. I'm very satisfied... at least as much as I can be based on visualization.

 

Unusually the relay box that normally mounts on the shock tower has been relocated and the earth zip-tied in a weird and wonderful way.....wow that outlet from the IC must take the cake for creative boy racer plumbing! Roof condensation inside the car would be fairly unusual, at least over in this climate, short of windows left open in the rain.

Hackery to fit the gauges is a bit of a concern too, might find dash removal easiest to remedy that, but pulling irreplaceable early painted plastics with the structural integrity of a potato chip would be nerve racking.

Must the car be a 92 resident in Germany already with a past registration history, or is it any FD of that year?

 

Yeah honestly i have never seen moisture buildup like that in an engine bay but that garage was fucked. Engine sounded pretty ok for me as well, propably defective MAP sensor hence why no AFR reading and/or vacuum leaks.
Steering rack is also a good point, might as well be from there.


Looked worse than a slaughterhouse aftermath to me, but i am not a big fan of cables in cars anyway.
No, the car can be from anywhere on the world as long as the first registration was in 1992. Maybe not Russia, i think we are not allowed to import directly from there. It also must be without a sunroof, i can't fit in the sunroof models. Open for any ideas and i am searching everywhere i can imagine.
As of now, i would propably steer away from it. Moisture and cables chopped up is too much. I also have to factor in the single turbo kit, all the expensive paperwork, bodykit, painting. Don't want this to cost me north of 50k€ that quickly.