1993 Buick Lesabre Self Acceleration

No sir never have. And I definitely wouldn't mind changing them if it will improve my car's performance. However, first I want to check the engine vacuum like you suggested. I'll get back to you depending on what I find. Btw are the crank and cam sensors the same thing? Where are they located and is it very complicated to change them?

Disregard that last question I already looked it up. Actually while I was hunting for a vacuum gauge at a local auto parts store, they told me that another way I can tell if my engine vacuum is fine is that when my ac is on, if it changes quickly from vent to defrost, which mine does, then the vacuum is fine. So would you recommend I still buy the gauge? Also at Autozone they showed a vacuum pump which they rent. It looks like a gun and it has a gauge mounted on it along with a long rubber tube to goes to wherever you're supposed to connect it on the engine. They told me you pump the trigger and you watch how much the pressure falls. Is this the tool I need? Because there's one that I found online that looks closer to the picture you posted. It's just a big gauge with a long rubber tube and a little T adapter. Which one is it?

Ok today I conducted another fuel pressure test. And I believe my problem may be a bad fuel pump after all. First of all the pressure with ignition to ON was at 36 psi, when engine specs say it should be 41-47 psi. Then with the engine on I pressed on the throttle slowly at first ad then harder. The pressure should have risen about 5 psi, but instead, it remained the same and the needle even dipped lower that 36 psi for about a second. According to the source that posted this test, this is due to a bad pump or clogged filter. But since I already changed the filter it leaves only the pump. Which when I think about it makes more and more sense. This explains why the erratic idling sounds more like an erratic flow of a liquid, and why it sounds sharper right when I step on th gas, especially in the morning when the car has been cold for hours. Im still gonna check the engine vacuum, but now more than ever I am convinced that it is a bad fuel pump. What do you think? And also do you think it's better to buy the pump from an after market place like Autozone, or a place that sells OEM parts, there's a place nearby that sells AC Delco brand products that they claim are factory original.

Hello again. Ok today I changed the fuel pump along with the strainer. I checked the fuel pressure again and it is reading 42 psi with ignition to ON. For my car it should be between 41 and 47 psi. BUT. The symptoms are still there. I turn the engine on, and the erratic idling starts right away, the uneven roar of the engine. It lasts for about 4 or 5 seconds then it goes away. Something new too. The needle that marks the fuel level on the dashboard does NOT work. I filled it to a little more than a quater and the needle just stays in the empty position. What's next? Thanks again for your help this is really frustrating.

I apologize. I wasn't trying to make it sound like you're not trying. I really appreciate all your help. Im just frustrated with my car because it almost seems like the more money I throw at it, the more it breaks. Ok a few updates, just yesterday for some unknown reason, the fuel level needle on the dash started working again. So that's fixed. Pressure on the fuel rail is also within specs. But the noise I mentioned to you before is still there. Like an erratic purr of the engine especially when I step on the gas. I also checked for codes again and I got 34, which is a low reading by the MAF sensor. So I took it off and cleaned it and now the bad code is gone. But the noise is still there. What else is there? And thanks again for your help.

Ok today I tested the engine vacuum. I got a reading of exactly 17 inches of pressure. Then I proceeded to test further following these guidelines I found on Google. I opened and closed the throttle quickly and the needle would quickly jump from around 2 to 20 inches quickly, then return to normal. I also noticed that although it would stay at 17 in, the needle would vibrate slightly. But at a higher fixed speed (by opening the throttle more and holding it there) it wouldn't vibrate at all. So what's next? And thanks again.

Smooth and steady idle
(800 to 1200 RPM) Between 17 to 21 inches Engine is in Good Condition, but perform next test to be sure.

Open and close throttle quickly Jumps from 2 to about 25 inches - Engine is in Good Condition.

Smooth and Steady, but lower than normal reading Worn rings, but perform next test to be sure.

Open and close throttle quickly Jumps from 0 to 22 inches Confirms worn rings.

Steady idle - Intermittent dropping back 3 or 5 divisions and returns to normal Sticky Valves. If injection of penetrating oil into intake manifold temporarily stops pointer from dropping back, it's certain the valves are sticking.

Steady 3000 RPM Pointer fluctuates rapidly, faster engine speed causes more pointer swing Weak valve springs.

Steady idle Fast fluctuation between 14 to 19 points Worn intake valve stem guides. Excessive pointer vibration at all speeds indicates a leaky head gasket.

Steady idle - Constant drop, Burnt valve or insufficient tappet clearance holding valve partly open or a spark plug occasionally miss firing.

Steady idle - Steady 8 to 14 inches, Incorrect valve timing. It must also be remembered that vacuum leaks and/or poor compression can result in a low vacuum reading.

Steady idle - Steady 14 to 16 inches, Incorrect ignition timing.

Steady idle Drifting from 14 to 16 inches, Plug gaps too close or points not synchronized.

Steady idle Drifting 5 to 19 inches, Compression leak between cylinders.

Steady idle Steady below 5 inches, Leaky manifold or carburetor gasket, or stuck manifold heat control valve.

Steady idle Floats slowly between 12 and 16 inches, Carburetor out of adjustment.

Blipping engine speed, Quick drop to zero then return to normal reading Muffler is clear.
Blipping engine speed, Slow drop of pointer then slow return to normal reading, Muffler is choked or blocked.

That's ok. I understand these things can be difficult. Thank you for all your help and if you find out anything else just post it when you have a chance.