97 Tacoma fuel pressure regulator-vacuum controlled?

No, the vacuum line on a 1997 Toyota Tacoma's fuel pressure regulator does not directly connect to the airbox. The vacuum line on the fuel pressure regulator typically connects to the intake manifold, providing a reference for engine vacuum. This vacuum is used to adjust fuel pressure based on engine load, ensuring the correct air/fuel mixture. This is googles comment! There has to be 1000s of gen 1 tacoma owners on this forum-can someone come forward and explain the so called vacuum controlled FPR situation on 2RZ-FE-we all know there isnt any vacuum on that line!! WT*? Maybe just maybe this is why these engines have rough idle, even when driven off the show room floor they idle rough-motor has a balanced crankshaft!!

 

I think you're wrong there......the most likely reason for rough idle is a vacuum leak somewhere
....gummed up IAC is a close second....

and there is a bunch of places to leak there...
like a stuck open pcv valve.....or IAC valve not throttling right..
and any of those connections tied into that tube/intake area right there...

the lower part of the pcv grommet can be sheered off and leaking profusely....
even a failing brake booster could be bleeding off all your vacuum

so I'd check your vac at different places

and realy best thing would be check and recheck everything with a smoke machine.

long shot would be egr valve is not throttling correctly.....or its passage on the intake is all carboned up

really surprising most of you dont replace any of the engine rubber stuff.......
until the horse breaks its leg.......like most think toyota has magic forever parts....


I really doubt the F R regulates or varies much.......just keeps the top end from over surging


I have 2rz and idles just fine.......about as smooth as the 3rz I used to have

 

Inline 4 engines are inherently unbalanced-2 pistons go up at the same time-thats why the 2.7 has a balance shaft-injectors that arent flow matched can also cause rough idle plus a worn distributor cap!!

 

I'm telling you I've driven both 2rz and 3rz for 10's of thousands of miles....

there is no discernable difference when tuned up and running correctly


they are small engines so they have some movement.....and they are noisy from ticking solenoids and valves


worst I can say about 2rz.....is they are gutless with the auto trans........better allow some merge room


I believe the balance shafts are a complete miss on this application.....
and just introduce another point of failure....

the 3rz was introduced 3 yrs earlier in 1959......and was modeled after an existing marine engine with as little changes as possible......that's the reason those balance shafts are in there

 

Example:The 87 buick park avenue had a 3.8 engine the that idled very rough-that engine became the 3800 with a balance shaft and idled smooth! The 3rz motor came out in 1995 to replace the 22r motor!

 

2RZ-E

2RZ-E Engine in a 1994 Toyota HiAce (RZH101G)
This is an SOHC engine with two valves per cylinder. Valve adjustment is by shim over bucket. Output is 120 PS (88 kW; 118 hp) at 4800 rpm with 146 lb⋅ft (198N⋅m) of torque at 2600 rpm. It does not have balance shafts and is known for vibrations.[1] Originally manufactured with a carburetor induction system, it was later upgraded to Electronic Fuel Injection, with the -E suffix added to the engine designation. Toyota specified unleaded fuel with a rating of at least 91 RON in Australia.

 

3rz/2rz is not an updated 22r/22re......3rz was put in production over seas in 1959
.....22r came out somewhere in mid 70's

22r is a junk engine....made to fit a chevy luv size lightweight
......only good about these.....is you can do an engine swap in a day

Anything can idle rough for all kinds of reasons

really what you want to do is feel the engine pulling away from a light
in the 1700 to 2500 rpm range.......is it smooth

my 2rz is butter smooth in that range

everyone that does that balance shaft delete in 3rz......says no discernible difference


problem with SOHC is those rocker arms.........that whats exactly failing the new Jeep 3.6 engines today
AS those needle bearings go bad they start running like crap