2800-3k sputter and hesitation
 

okay so this started happening when I was driving through a neigborhood and there was a dip in the road and I didnt see it then my car pretty much slammed to the ground, so I pulled over and checked everything under the car and everything was fine, but then this problem started.

The spark plugs are fine, I cleaned them numerous times, and cleaned all the grounds. Ive checked all the vac lines.. any ideas? Heres a video.




engine related mods:
emissions removed
Streetported motor
RB main pulley
MBC set to 10psi
Walbro 255

You might want to test the Boost Sensor and make sure the hose is well connected. And you say you cleaned the grounds but the most important one is the engine ground which is not accessible unless you pull the UIM. And perhaps you jiggled something loose in the converters. And also check the mounting of the coils to the fender. And for the heck of it test the TPS.

Yeah I took off the UIM and took some sand paper and made sure they had clean connections, and yeah I took a look at the boost sensor, looked fine, I'll check the coils too.

Is this the same car w/the poor compression that you mentioned on another forum?

yeah but it ran fine before but for all I know its because of flooding, its running very rich its starting to black out my rear bumper lol

so ive noticed whenever I try to hold a steady throttle will hesitate and feels like it loses power very briefly, doesn't really matter the rpm, I was cruising in 5th at 2k with -10 vac, maybe its a vac leak somewhere? tps maybe?

I have a very similar hesitation and power loss that you explained, I can't figure it myself. Makes my car undriveable.

Alright heres two more videos I made.
First one is warmed up doesnt matter the throttle position.


This one is just sitting revving under no load.

The throttle linkage resting upon the TPS plunger disengages at about 3000 rpm. You might want to unplug it and see if the problem persists.

the tps was disconnected in those 2 videos.

Sounds like a injector issue or a tps adjustment issue.

Alright so I got it fixed, turns out there was old gasket left on the UIM that was causing a leak, fix itm runs great now, but for some reason my car is idling around 2k

Vacuum leak, throttle cable needs adjustment, Fast Idle Cam out of adjustment, sticking throttle plates, cruise cable needs adjustment.

Cant be a vac leak, redid the vac caps and only using 3 lines. Cruise cable not hooked up.

Fast idle cam, not sure about that, i'll look into it

Did you find the problem?? if so how did you fix it? i have the same problem

"Runs better" doesn't mean problem fixed. Did you test voltages/resistance at your TPS?