air intake (heated vs non-heated) and IAC bypass

[kthnos]

good the injectors do not leak, very good.
the key on pressure is low. 36-43 is spec,
higher end is at sea-level . seem slow to build up,id suspect filter, now.
the shunt test of 55psi will show pump is robust. but that short hose at FPR to rear is very hard to pinch. and if old harder.

idle is 30-37
but when engine starts, hot, the 19"hg vacuum , causes the FPR pull pressure down about 6psi
most do 40 keyon ,then drop to 34.

for full power at WOT, you need 36psi, min, at sealevel.
old FPR can leak inside and lower pressures (wear) and stick. many this old are on death throws.'walking wounded"
we also know the check ball in pump is good now, good #2

the pump runs for 3 seconds, usually gets full pressure in one second. (ran say yesterday, not drained with new filter. might take 3 keys on. to prime it.)

the filter (air ) only with no filter at, might add 1hp at wot. but the dirt would be bad.
so all filters restrict (except the centrifugal types (huge spinning drum and motor) but media filters all restrict, on to next same micron hole sizes.
but some have deeper pleats.. and ive never checked that. but would suck more air for longer time, to make it full of dirt.. sure.
id buy the one with the most filter area... if so inclined, usually just happy for one to last 1 or 2 years and pop a new one in.

nothing wrong with a wix or any other filter, top brands,

but oil filters i like "PURE-one". with the tighter media it has.

one other trick to see fuel filter issues
is its test port, 6mm screw at filter banjo bolt, if pressure is 50psi there just key on, the filter is packed.
seen many do that. and slow pressure rise at rail too.

i am talking about the K&N air filter specifically (if you have any feedback/thoughts on this i meant).

just came upstairs from the garage. did a little more testing with the gauge.
initial numbers that i posted were right after the gauge installation (maybe an air pocket there?).
somehow, this is what i got now with the leak test: (double checked)

-key ON once: ~34psi
-key ON twice: ~38psi
-pressure after 1minute: ~38psi
-pressure after 10minutes: ~36psi
-pressure after 30minutes: ~30psi

i need to check idle pressures now, but its getting late so it will wait till tomorrow.
thanks again for your help fixkick!