crusin92red5.0

so i was having issues with it bucking and poping in the manifold when i shift between 2nd and 3rd so today i decided to mess with the fuel pressure. First i bumped it up to 45 psi vac off and it chugged. then i turned it down to 36 with vac off and it almost eliminated it. I moved it a little further down, maybe 34 vac off,30 vac on and it didn't buck. Is there anything wrong with running it this low? Also i don't know 100% but it felt a little slower (could be me imagining).

Does fuel pressure have impact on i guess horsepower?

Is 34 psi with vac off ok or normal?

thanks

mjr46

normally I run it a little higher with vaccum off and if you run it to low, it could lean it out and cause hesitations

crusin92red5.0

So do you think i'll be alright with the way i described above and is it normal to drop 4 psi when you plug the vac on?

or is it unsafe and i should live with the hesistation/bucking.
Have you ever seen this prob before?/ or do you think i'm just underlying the real problem? (that i don't know of)

i might be able to bring it up to 35 psi.


or is it unsafe and i should live with the hesistation/bucking.

mjr46

yes it is normal to drop psi when vac line is hooked back up, that is the purpose, at idle and cruise Fp doesn't need to be as great as it does at WOT

crusin92red5.0

so i need to check psi at WOT?

mjr46

no removing the vaccum line would simulate what psi is at wot, manifold vaccum is not present at WOT

crusin92red5.0

Oh. so will i be safe running it the way it is or is there another problem?

If there is another problem, is there a way to go through the stepping process to fig out why it bucks?

thanks again Mjr

mjr46

Run a koer test is one way to check system operation for lean or rich codes or any other issues the ecm may see

crusin92red5.0

Hey is it normal for the fuel pressure to bleed down after a few hours have passed?

Night Terror

after the car has been turned off you mean? or after it has been runing?