I am working on a ‘89 with a 2.8L.
When ever I attempt to accelerate, there is MAJOR hesitation, as well as missing, as if the engine is starving for either fuel or air. I have approximately 45 PSI (fuel). When the accelerator is depressed, I can hear a soft, whining (very high pitched), that sounds like it is trying to suck air from the outside. As far as I can tell, this is coming from the intake side of the throttle body.
So far, I have changed out the O2 and MAF sensors. I am at whit’s end, and cannot figure out why it is starving.
Has anyone else encountered such an issue, or know what may be wrong?
Thank you!
Joe in Arizona

 

I had a LG4 that did the same thing whenever the primaries opened up on the carb..IE it was getting too much air. So in your case I would say your car is getting more air than it thinks its getting. So I say...vacuum leak. you can use some carb cleaner to spray arround the engine compartment to locate the leak. What will happen is when you spray in the spot where the leak is the engine will rev up.

A way to tell if it is a vacuum leak w/o popping the hood is if the idle has gone to kibble.

 

Is the SES light coming on? If so, have you retrieved the trouble code(s) being set?

How long since the last tune-up - plugs, wires, cap, rotor, etc.?

 

I can not find any vacumm leaks, there are no codes being set, and all changable parts have been changed within the last 500 miles.
This problem just started, and it is acting like it is not getting enough air. When you pull the throttle, there is a whine, as if it is trying to pull mor air through the throttle body than it is being allowed. My Fuel Pressure is around 45 PSI.....
When the Mass Air Floe is disconnected, the car runs good......
Any other ideas?
Thanks to those who have replied!
Joe