74 1.8 - fuel pressure regulator?, opinions. Options

[wonkipop]

car = 74 1.8 L jet (all intact).

problem =
out driving this morning - gradual then worse loss of power. no accelerator response.
pulled over. cut out. no idle. let it sit for a few minutes. restarted it. got it going.
got up road all right, but symptoms kept coming back, then going away. limped it home.
fun ruined for driving, but fun diagnosing started.

felt like your classic fuel starvation.

background. car has been recommissioned and back on road for about 5 months.
running beautifully.
fuel system entirely rebuilt. clean tank. new fuel lines. new fuel pump. new injectors.
all vacuum lines renewed. all ignition compenents renewed. except coil (which could be original, looks like it, but coil was tested and was a goody).

one thing = fuel smell in engine bay on lhs around air cleaner. comes after a few days sitting. had put this down to saturated charcoal cannister, feeding back fumes into aircleaner. have inspected all fuel lines etc thoroughly and no signs of any external fuel leaks/wetness. just a vapour smell thats not there all the time, just after sitting.

pulled everything apart today down there after getting home today.
checked everything. all tight, no air leaks. no bad hoses.

looked at pressure regulator. which sits right there under aircleaner.
i have no reason to think its not original and about 45+ years old.
and did not get replaced. looks great externally, but.........internally?

will get car into shop this week. where i can get some guages on it etc.
at home with car. nothing but basic tools.

but whats thoughts out there.
anyone had this one before.

[wonkipop]

just been on a 340km round trip run up country to euroa for the weekend.

getting much closer to sorting out the problem.
several problems intersecting at the same time?
unsurprising - its been recommissioned after 16 years sitting.

1) i've got rid of the cold start warm up issues.
think it was two things going on leaking air after the AFM flap.

one - throttle body. hopefully new throttle/plenum gasket fixes that long term - in the short term its stayed tight.

two - a collapsing hose from Aux Air Valve for cold start.
i've rigged that so it does not collapse with hose clamps.

result three perfect cold starts in the mornings (one of them reasonably chilly for southern australia at the start of autumn out in the countryside) - no hunting no fuss.

2) i've still got the almost dying and uneven hunting idle but occurs only under the following conditions.
caught in stop and start traffic, on hot/warm days.
listening closely i can hear the fuel pump struggling, making noises, changing pitch.
fairly sure the culprit is the mild steel fuel lines i have run down the tunnel and the section leading from firewall exit to fuel pump. sitting in traffic the car is sometimes sitting in its own hot air and its building up under the car in certain circumstances.
both times on the trip up and back i had the problem at the same spot leaving the city and coming back. a long sequence of about 6 traffic lights with long lines and delays at the lights.
i'm going to try and insulate the lines to protect them from the heat build up.
the fuel is maybe boiling in the line section in front of the pump making the pump cavitate and struggle to make pressure in those conditions?
- think you are right @timothy_nd28 , the fuel delivery is getting in the focus again.

good news.
its been at least 20 years since the car has done a good long run.
it got it.

out on the "interstate" it keeps on winding out.
i took my eyes off the speedo a few times and it was running up to 90 mph comfortably on its accord - turbine smooth, had forgotten what this car was like at speed cruise.
(in australia sadly that would mean instant loss of license and car impounded if the cops got you in the radar gun or pole cameras - so i had to start being careful after i let it happen a few times).

happy to sit and cruise at 70/75mph all day long.
run up through a great little back road twisty enscarpement climb with lots of sharp corners.
no coughs, no stumbles.
gave 8.9L per 100k or in usa-speak 26/27 miles per US gallon.

getting used to the thin michies, feel good on second rate little country roads with uneven pitching surfaces.