Odd torque loss when driving near redline

[Stand-in]

For what ever reason my engine doesn't produce the power I would expect north of 3800 rpms, it has that initial grab, and doesn't sound off, and nor do I suspect that its a fuel issue. I have redone everything with regards to the fuel, and have a good ear for it, its a smooth entrance into low power.
Spark plugs also say that the fueling is optimal, and I don't have any issues with compression. However I do note that the car gets very loud very rapidly past around 3800 rpms. 1-2 seems fine, 3rd shows signs of a problem and then 4th gives up entirely at exactly 4 grand.
While I should not probably be going these speeds I suspect that either I am horsepower limited (Are these cars supposed to be able to reach 5800/6000 rpm in 4th? M10b20 for reference) or more likely the springs are too lose and are giving me all the advance at a lower rpm.
I am going to get some distributor springs and play around with them as no one offers recurve services where I live, much less has a tool for bosh dizzies. Any thoughts before I start playing pin the tail on the pony with regards to curves? I will also be reading up in my BMW workshop manuals.

I also have a issue with my alternator right now, the bearings are not happy after 10 years of sitting and sound like the devil incarnate when getting on it/riding above 3000 rpms. So that might just be the issue there, unlikely as it may be. In any case I will be messing with that prior to anything else.

[Jeroen]

Well at least the engine should be able to go well beyond 4k rpm, probably will run out of power before reaching redline in top gear, but it should be able to come close. But, so many options! Firstly, does it drop dead, or loose power dramatically? If it drops dead it may be the mechanical rev limiter kicking in too early.

I expect if to be the 2nd option, and you don't have any funny air flow obstructions it can prolly only be one of two, ignition way off, or a fuel delivery problem. Can you do an exhaust gas analysis? Perhaps running dangerously lean?

[Jeroen]

Well at least the engine should be able to go well beyond 4k rpm, probably will run out of power before reaching redline in top gear, but it should be able to come close. But, so many options! Firstly, does it drop dead, or loose power dramatically? If it drops dead it may be the mechanical rev limiter kicking in too early.

I expect if to be the 2nd option, and you don't have any funny air flow obstructions it can prolly only be one of two, ignition way off, or a fuel delivery problem. Can you do an exhaust gas analysis? Perhaps running dangerously lean?

[Stand-in]

Well at least the engine should be able to go well beyond 4k rpm, probably will run out of power before reaching redline in top gear, but it should be able to come close. But, so many options! Firstly, does it drop dead, or loose power dramatically? If it drops dead it may be the mechanical rev limiter kicking in too early.

I expect if to be the 2nd option, and you don't have any funny air flow obstructions it can prolly only be one of two, ignition way off, or a fuel delivery problem. Can you do an exhaust gas analysis? Perhaps running dangerously lean?

It doesn't drop dead, it just tapers off in power and stops accelerating. I don't currently have a mechanical rev limiter installed, so I can just float valves all day. It might be the spark coil as its just a coil for a vw bug, and its slightly higher ohmrage, and I had let the key sit in ignition back when I didn't know that was an issue. If I add any more fuel at idle it starts to seek, I could do an exhaust gas analysis but I would suspect it would be a problem at higher load, and I don't know if that's an option. I just tune my fuel ratio to the best vacuum at idle. More than 1/4 screw richer mild seeking, in the other direction pops in the exhaust, and rough idling as the fuel injectors stop accurately partitioning fuel. In between these is about 2 inches of mercury that I can extract in efficiency.
I will take a video today, in about 9 or so hours, showing it at idle and also how it gets up and goes.

[Stand-in]

Ok well the video was a moot, my friend got into a car accident, and needed help to "skin" his car. Though I did have some odd symptoms that queued me into realizing I needed to get crud out of my warm up regulator again, and I managed to fix that. That improved things, I beat my friend in a drag race (I have been chasing him for months now, its a good reference as to if what I am doing is actually changing anything); same friend that crashed today too....
The warm up regulator helped out a lot with the power loss, and fixed most of the blue smoke I was experiencing when getting away from a stop. Still I should do my valve stem seals at some point. But I also noticed a slight leak from my fuel pressure accumulator, so perhaps that's pushing things in a weird direction too. Now in second it falls on its face close to redline, but that might just be intentional. Its like a power cut almost, though doesn't sound like any rev limiter I have ever heard. I also have found a source for used alternator parts near me, so I can build my own and avoid the dreadful cost of 300 for a known good one. (That's ridiculous for a 60 amp piece of kit, and they're all old stock too).
Poor Celica.... at least you were the econobox version..... Its sad you've been crashed at least 10 times in the last year.....

What's really wild was that was a fully paint prepped front bumper, worth 800 big ones. Now he's looking at a 1000 dollar hood, will this guy ever learn?

[Stand-in]

Further reading, the car has been off the road for 6 months of the last year, as I was helping him rebuild his motor in my spare time. Oh well, at least he's having fun.

[Jeroen]

Pity about the Celica, but I guess you guys are determined to get it back on the road again?

Aaaaand, small steps... but WUR and a leaky accumulator could make a huge difference already. Perhaps more leaks? Any fuel smells around the car? Dirty fuel tank or pick up?

Funny what happened close to redline in 2nd, with no mechanical limiter installed... don't know what else could cause this.

[Stand-in]

Pity about the Celica, but I guess you guys are determined to get it back on the road again?

Aaaaand, small steps... but WUR and a leaky accumulator could make a huge difference already. Perhaps more leaks? Any fuel smells around the car? Dirty fuel tank or pick up?

Funny what happened close to redline in 2nd, with no mechanical limiter installed... don't know what else could cause this.

Lol, we just removed the outside of the car and put her back on the road, I think we are going to turn it into a parts car after we drive the piss out of it. He's looking at another one, this time a manual and a better engine.

The WUR made it damn near perfect, but after cruising around a few days it clogged (propped open the diaphragm )again, the screen is perforated and failing apart, so I think I'm just going to remove it. My fuel system at this point is clean and doesn't have little specks floating through it, its very visibly metal in it.
As for the 5800 rpm cut off I think its just valve float, sounds kind of funny and pulls strong up to that point, or its a ignition issue. Almost like its breaking up. I am running a higher resistance coil and I do have a few weird drains on the battery so that is a consideration.
Edit, its possible the fuel relay is not receiving a signal at that high of an rpm. Also it doesn't turn on unless I start cranking the engine, was that a later model feature?

[Stand-in]

Link to photos of the wur issue.
https://imgur.com/a/Y1D1Cbg
The 5800 rpm fuel cut problem has resurfaced, this time as a load based surge issue. Even after I reline my tanks the filter somehow manages to clog. What the hell. I haven't had issues with it for while so perhaps I will have more time on the next one. And here I thought I had everything sorted.

[Jeroen]

Can't see that clearly but apparently something is clogging your fuel system. What kind of material is the dirt? Like rust, rubber, or?

[Stand-in]

Can't see that clearly but apparently something is clogging your fuel system. What kind of material is the dirt? Like rust, rubber, or?

The material in the wur is metal from the disintegrating screen that keeps crap out before it. I just took a drill bit and hand reamed it out. Otherwise everything is clean. I no longer have rust and sediment, with regards to the clogging, what will really be telling is what I find in my filter and then failing that the pick up screen. The WUR isn't clogging, its just the metal is propping open the diaphragm. So if anything its doing the opposite. It causes a rich burn condition, and sounds like you have a stuck choke when you get on it/poor performance before that. I am not experiencing that right now.

[Jeroen]

Clear!

[Stand-in]

Ok, I have some further developments. It turns out you need to put the lock washer on after the flat washer, and you need to give the nut a good torque on the WUR. That stopped my fuel starvation. I think my car had been dumping a crazy amount of fuel into the chamber, enough at its worst to foul the plugs. I have leaned the car out a bit and it pulls harder, and I don't think its the wur doing the problem at this point.
As I understand the mechanics of the part, it doesn't set a pressure, it rather sets the difference between two pressure, IE stepping up or down a pressure to a given ratio. SOOOOO, with that in mind I think the part in this diagram, https://www.realoem.com/bmw/enUS/showpa ... Id=13_0124 is leaking or letting too much fuel by. Causing a rich condition on acleration/load.
I also had a chance to get on the freeway today, I ended up going to "Germany" in the manor of but five minutes, enabling me to do a cruse with mustang that lasted for forty minutes. The reason why this is important is because we got up to in excess of 100 mph, and I found that the car kept pulling past that 4000 mark. (Glad my cooling system is mint, I was very surprised to see my temperature gauge at near the red mark.)
So problem solved, but not yet fixed.
Further, I went to a large city near me as part of said cruise and absconded with quite a haul of parts for a meagre 80 dollars; looks like I am now in the parts business.
Kjet symptoms are weird and seem to have many overlays of symptoms. After I mess with this last part on the fuel system everything in it will be new or made new by me at this point.
(EDIT)
Further further, shame I bought a fuel filter, erm rather four of them, but at least they were 67 cents each on clearance special.

[Stand-in]

Ok I put an additional spacer behind the spring in the diagram, and my butt dino says I gained some horsepower. But I have a really bad rich condition on first start up, kind of like a stuck choke, and I end up just reving it for a couple seconds so it doesnt die. This isnt new however, I think the end of the plunger may be leaking. So I will be removing the spacer and swaping in a new oring.
My only question at this point, is should there be alot of smoke when reving it agresivly or when geting on and off the throttle in 1st? Theres no issue when idling or with smooth pedle operation, or when in a higher gear, or when crusing. I am begining to wonder if the dianamic load is just getting away from the inherent limitations of kjetronic.

[Jeroen]

If it's black smoke that is a lot of unburnt fuel.