79 Campmobile won't idle with brake assist in

[cv66seabear]

79 Westy, Type IV Engine running points and a Super Beetle Distributor. Engine rebuilt 2022. Ran great up until a bout 2 weeks ago, just before a trip to Michigan.

Symptoms: Cranks well and will start and idle roughly when the brake assist hose is unplugged! Otherwise, will start, but depressing the accelerator pedal all the way down, gives a rough idle for about 5 secs, then stalls. Stall immediately when brake assist hose is replaced.

Tested/Checked:
with Noid - 3 and 4 FI both light up, have not tested 1 & 2.
Unplugged and checked CS wire, idled a little better then stalled
Spark at plug wire (Distributor cap)
Brown Ground Wire to Double Relay tight and seems ok
Looked at Double Relay, cleaned pins and sockets, look ok
unplugged and checked X connector (someone drew an X on a lone connector).
Checked ECU plug connections, pins look ok
Checked TS2 - at .954 ohms. (Bentley says 2500?)
Checked AFM fuel pump clicks and comes on, cleaned contacts Ohms read ok Pins 1 and 5 read 1.346
Sprayed Intake with starting fluid (I think - see picture) engine revved when I sprayed 3 & 4 and also at the Aux air (? see photos again) hose (which does seem a little short, also revved).
pushed in every hose - added a zip tie to the top hose at the decel, as it would backfire and blow this hose off.
Took apart and cleaned every connection with electronic parts cleaner I could find.
Removed gas cap, no hissing or sounds.

I have not done a fuel pressure test, as I am a novice and probably need adult supervision!

Any ideas oh hive mind?

[cv66seabear]

Update -
Timing is at 6 before TDC
Ohms at AFM with one probe in #1 and 1 in #5 reads 3.38 ohms
Another check on the TS2 gave me an ohms reading of .814

[Amskeptic]

79 Westy, Type IV Engine running points and a Super Beetle Distributor. Engine rebuilt 2022. Ran great up until a bout 2 weeks ago, just before a trip to Michigan.

Symptoms: Cranks well and will start and idle roughly when the brake assist hose is unplugged! Otherwise, will start, but depressing the accelerator pedal all the way down, gives a rough idle for about 5 secs, then stalls. Stall immediately when brake assist hose is replaced.

Tested/Checked:
with Noid - 3 and 4 FI both light up, have not tested 1 & 2.
Unplugged and checked CS wire, idled a little better then stalled
Spark at plug wire (Distributor cap)
Brown Ground Wire to Double Relay tight and seems ok
Looked at Double Relay, cleaned pins and sockets, look ok
unplugged and checked X connector (someone drew an X on a lone connector).
Checked ECU plug connections, pins look ok
Checked TS2 - at .954 ohms. (Bentley says 2500?)
Checked AFM fuel pump clicks and comes on, cleaned contacts Ohms read ok Pins 1 and 5 read 1.346
Sprayed Intake with starting fluid (I think - see picture) engine revved when I sprayed 3 & 4 and also at the Aux air (? see photos again) hose (which does seem a little short, also revved).
pushed in every hose - added a zip tie to the top hose at the decel, as it would backfire and blow this hose off.
Took apart and cleaned every connection with electronic parts cleaner I could find.
Removed gas cap, no hissing or sounds.

I have not done a fuel pressure test, as I am a novice and probably need adult supervision!

Any ideas oh hive mind?

I would like to clarify your symptoms.
Engine runs worse with booster hose plugged in?

a) block off brake booster nipple on intake manifold
(hose can remain dangling, but note that you do not have assist)
b) check each terminal in the AFM plug itself (female contacts) for correct insertion depth.
Sometimes they get pushed back by a clumsy plugging-in operation, roll back boot on plug and pull loose wire/terminal out, re-bend the finger on its "back" and it will click into place and stay once more)
c) warm engine and tune it for correct running.
d) any deterioration in running when you put the booster hose on suggests a bad booster, check valve, or hose between engine and booster itself.
Colin

[cv66seabear]

Update:

Engine was pulled after compression, leak-down and fuel pressure test. Fuel Pressure was at 50#, so replaced the regulator.

#3 had an intake valve that had pulled out the lining and was jammed open. Bought new heads, new valves and a few intake hoses and should be back Monday. Bought AMC Heads that Painters Grinding in Denver went over and prepped for the install.