My 95 SR is all of a sudden doing a lot of stuttering. I thought it was because i put regular fuel in it, but its still acting this way even with premium fuel. It happens more at the lower RPMs (2 and under) or going uphills. It doesnt appear to happen all the time either, although yesterday it seemed pretty bad during a 45min drive.

Does anyone have any ideas what could be the issue?

Thanks

EDIT: No check engine light is on

you kno me im going with the hose on the fuel pump in the tank but that is just me prolly tps

Probably the intake leaking. Butterfly valves.

im not sure how it could be a leaking intake seeing how this issue doesnt happen all the time. How could the butterfly valves be causing this

Also: im not sure if its the tps bc im not getting any jumps in RPMs or a wildly inconsistent idle jump

So just an update...

I havent had another day like my 1st post, but it seems the only time i can duplicate the stutter is from a complete stop and punching the gas hard, and that only lasts for a sec. This doesnt happen 100% of the time either

Based on my experiences, it could be one of two things:

1. Vacuum leak. Usually this presents itself as a rough or slightly off idle. But as soon as you rev it is fine.
2. Misfire. The car might be misfiring while you're driving at higher revs, but you can't feel it. Misfire is very present at idle...although it could be a light one. Usually with a misfire, you'll hear the car "PUT-PUT-PUT" when under load (like accelerating).

Since your car is a 95, it is OBD1, so the car is in essence a bit less sensitive (relative to OBD2) and may require more to get the CE light on.

the weird thing is, idle is always dead on, and reving at idle is smooth and consistent

So idle isnt as smooth as once thought, but isnt bad either, it seems to idle between .50-.75 rpm, but not always, sometimes it is smooth.

So for the last couple months it hasnt been much of an issue, the only time I notice any hesitation is when hitting the gas hard from a stop and even that isnt 100% of the time. I just ran my gas tank down real low, the light was on for a while. And for the last 3 days Ive had the stuttering issue while driving, it just started to return back to normal today stuttering alot less.

I think im gonna start with changing that little tube in the gas tank?
Also, side question, are 3.0L tachs compatible with the 3.5L engine?

Im still dealing with this issue and i think i finally figure out how to duplicate this issue all the time

I usually drive around town and only put a 1/4 tank of gas in when i need too, i dont drive the montero much. Anyways this stuttering ALWAYS happens when i fill up the gas tank, and the stuttering lasts until the fuel goes down to about the 1/4 tank level.

So based on this any new ideas on what could be causing this?

Have you done any further checking on the ideas that were presented the first time you asked the question?