Ghost of Kjets past.... (Inexplicable fuel pump death)

[Stand-in]

So at this point I have gone through my original, a delfphi, a bosh, and now maybe will go through a bosh fuel pump, and I am very confused as to why.
For context the car had lots of fuel system problems in the past and I have been fighting to fix the thing for a long time now; at this point I have cleaned the tanks, replaced the fuel filter (every time I have installed a pump, and did not even clog at the end of the pumps life), rebuilt the fuel distributor, and had my injectors cleaned. All of this has helped me and it currently run, but barely. An additonal problem I had found was the fuel return line was crimped for a time but fixing this seemed to help with nothing.
The current pump on the car was finicky and the thing would barely make it up my driveway before attempting to stall out, and would also scream as it idled, that is until this afternoon when I went to move the car its started fine and was idling quietly... until I moved the car ten feet and then it came back. I also then went for a drive and found that it was much better than I had left it and was able to keep up with traffic with no problem (albeit I was not going to get the acceleration I wanted) in the city. It went for a 2 mile jaunt and performed unnotably except when I had to get up the hill to my house, then it "bogged" down and I had to lightly put on the throttle just to move up the hill. I suspect this is because I had a psi "battery" of sorts that enabled me to get away with short acceleration and low load driving with out to much trouble, until the demand for fuel reached bellow what the pump could supply and the psi required for the injection to work. Also I replaced the lines coming up to the fuel pumps and see no leaks coming up to the distributor.

TLDR I have no clue what is killing the pumps, gas is clean, fuel distributor has no filter, filter and strainer before and after the pump is clean. Return line functions and is not crimped. Have blown out the lines before (ran gas through it). Also I replaced the lines coming up to the fuel pumps and see no leaks coming up to the distributor.

[Jeroen]

First possibilities that come to mind. If there is an obstruction after the fuel pump, it will have to work way too hard and break. Clogged fuel filter or line, pressure regulator inside the fuel dizzy, of a hose or line. But most common is a failing pressure accumulator, I think I'd try to bypass that first. If you have the possibility, measure fuel pressure at some points, for example incoming or outgoing at the dizzy. Incoming and return lines not reversed on the dizzy? One other thing, the current Bosch fuel pumps for E21's are Chinese rubbish and fail within very short time periods. Currently having good experiences with QH but Delphi should also be fine afaik.

[nic65]

quoto Jeroen, esegui un test della pressione e portata all'ingresso del partitore

[Stand-in]

First possibilities that come to mind. If there is an obstruction after the fuel pump, it will have to work way too hard and break. Clogged fuel filter or line, pressure regulator inside the fuel dizzy, of a hose or line. But most common is a failing pressure accumulator, I think I'd try to bypass that first. If you have the possibility, measure fuel pressure at some points, for example incoming or outgoing at the dizzy. Incoming and return lines not reversed on the dizzy? One other thing, the current Bosch fuel pumps for E21's are Chinese rubbish and fail within very short time periods. Currently having good experiences with QH but Delphi should also be fine afaik.

Well I did replace my fuel pressure accumulator too, as it had failed prior. I will look at QH in the future but I suppose for now its best to look at lines.
I don't suspect that the regulator is failing, I made no modifications yet and it seems to travel easily when I press on it with my finger, if anything it may make sense to raise the stiffness in my uneducated opinion.
As I mentioned in my prior I don't believe the fuel filters to be my issue as I don't have any past the main one and the main has >5 miles on it (they were broken and required a tear down of the distributor to clean so I might as well just delete them).
I checked the fuel flow chart and I don't believe that my fuel supply and return are reversed.
I will check my fuel accumulator and maybe acquire a tool that allows for pressure testing, but as I had mentioned my return line was crimped and as such may have reduced the function of the pump.

[Stand-in]

Well, I checked my relatively brand new fuel pressure accumulator, I disconnected the line on the in tank pump side and jumped the connection to find as much flow through the accumulator as I see on the return line from the distributor.
I may not even have gotten a hundred miles out of that thing before it failed, oh well. I am going to cap both ends of the line and just run it like that as its only going to give me a hard start. That is until I get a replacement. Hell my last fuel pressure accumulator didn't leak as bad, I might stick that back in for the time being.
How did this even fail? It might be a bad part from the get go but I still have my doubts......
I didn't turn on the car after installing the new pump, but it sounds the same as my newish old one, so maybe its ok?

[Stand-in]

hmm I drove it around the block with the new pump and the deleted accumulator..... the noise is still there. However I did notice that as I was testing the accumulator the line that ran to it was dry, and plugging it seemed to deafen the noise for the most part, perhaps there are more leaks in the line for air to get into than I thought. Hard acceleration seemed to be to much for the pump but with maybe 30 min of run time on it, it cant be the issue. I also noticed that the fuel sending line was pinched a bit running up behind the tank, but that was also not THE problem. I thought the in tank pump might have been the issue, but it seemed to be delivering fuel. So maybe some of the confections are loose in between them.
Its also possible that I had crimped one of the lines when I remounted the fuel tanks.... so I will spend some time looking through there

[Jeroen]

Puzzling indeed! What new pump brand did you fit? We had at least 3 new Bosch units fail here over the past year.

[Stand-in]

Found the problem!

The supply line was 1.3 inches to long, I only noticed it because I was checking for problems with the fixtures, it had been hiding behind the RR wishbone, also it seems I had forgotten to feed it through the retaining bracket. Still some fuel supply issues so I'm not out of the woods yet, how much of that is the lack of a fuel accumulator and how much of that is some other problem IDK. But for now its beyond drivable, it could also just be some timing and valve lash that I need to work out.

[Jeroen]

[Stand-in]

Well it works enough to get to and from work, but not enough to which I am happy with it. I still experience surging and so forth. I went out hooning tn and all was well for a bit but flat out in circles is not exactly fuel efficient and I found myself with a fuel pump on the loosing end of a battle. Though I don't hear any noises from the pump that would raise concern. Thoughts?
Also I am finding that my engine doesn't like to get above 4k, and that it seems to have little in the way of guts above 31/2k rpms

EDIT I suspect that it may make sense to get a braided cable from the fuel tank to the pump, it may be getting distorted somewhere and as the fuel pump has an easier time with the increase fuel consumption it may be collapsing.

[Jeroen]

Bad pumps are often noisy, but not always. Relay and fuse connections not corroded limiting current? Maybe the car needs an exhaust gas test, running too lean?

[Stand-in]

Bad pumps are often noisy, but not always. Relay and fuse connections not corroded limiting current? Maybe the car needs an exhaust gas test, running too lean?

The fuse and relay connections look fine, I also tuned it to highest vacuum, I don't know if that's how you are supposed to but hey. Well more rather I don't know if that's how you meet emissions but I don't have that here. If anything it might be rich bogging. I don't suspect a vacuum leak because I replaced all of the rubber and I disconnected my power brakes bcs they were giving me crap.
also in reference to the prior edit on my post above I did notice some random intermittent but pretty quiet buzzing, I suppose this may be happening under load, but for that reason you probably cant hear it.
Edit the fuel hose doesn't seem to be braided by default, that was just the prior owners doing. That said I think I will poke around in there

[Stand-in]

ok fixed a problem near the distributor, now it refuses to tune appropriately, looks like I tore an oring again, and will now have to rebuild the distributor....

edit the distributor was fine, had a little bit of sediment in it so I'm 90% certain its the injector, I suspect the higher flow rate caused something to become dislodged, anyways I have a tool to clean it out with so no biggy. Side note, I'm getting pretty quick at taking this thing apart. Also as I did not mention it the fuel hose had become crimped there too.
injectors were clogged, I managed to save two of them but the others did not respond to the cleaning, so now I'm waiting on two new ones. Its crazy to me that 10 seconds of running is all it took for them to get destroyed but that's how it is I suppose.
edit managed to get the injectors in a day, and took it for a spin, much better. Very little fuel starvation now but I still have some work to do. I will be replacing my line to the fuel pump with a braided line as it seems to be crushing under vacuum. Also I have to finish tuning my car as I'm hearing intermittent backfires (gas igniting in the exhaust not the other way around).