1993 Pontiac Firebird V8: Very slow to Accelerate?

Common complain on these engine models.

Its a old model car.

There are few tests and inspection necessary to confirm the fault causing the problem.


On 1993 Firebird formula didnt have alot of get up and go to begin with. Although the 6sp manual transmission version did have a top speed of around 150mph, the 1/4 mile time is only 14.9 seconds, which is not very fast. It only has 275hp and 325ft lbs of torque.

So if you are referring to take off times and fast acceleration, it really wasnt there to begin with.

If you just mean that it barely accelerates and seems to be bogging down on acceleration or hesitation,then parts needs to be checked out.

Check and confirm this information:---------

Is the check engine light on?

How does the engine run at idle - smooth, misfiring?

Any exhaust smoke while idling or accelerating from a stop? If so, what color and does it smell like fuel, coolant, or oil?

The first 2 steps at this point are to first pull the plugs and inspect them for being not just worn, but for signs of running rich(black and sooty) or too lean(whitish) and go from there in of course replacing the plugs, but then testing for vacuum leaks, check fuel pressure regulator vacuum line for fuel in it(replace regulator if found), and if ok, check O2 sensor for being black from soot and replace if needed,


2nd step would be to test engine compression. A worn out engine with low compression will be slow and loss of power on acceleration. if compression on any cylinders are under 100psi, or more than 10% difference between lowest and highest number, then unfortunately a rebuild is in order.

Start by troubleshooting this possibilities.This will help to confirm the issue.

Thanks.

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Car accelerates very poor?

There are multiple possibilities for this,

Disconnect the EGR valve and see if you notice any more difference.
Problem with MAF sensor,TPS,Coolant sensor,spark plugs,MAP sensr can also cause poor acceleration problems.


On acceleration does the engine feel like it has a misfire at all or does it just not have allot of power on acceleration?

OUT of this if you notice this as follows ..............

It will start to accelerate then it won't gain any more speed, pushing more on the accelerator doesn't do anything, along the way it feels like it might be misfiring (more of a slight hesitation) but certainly doesn't feel like the classic misfire.

If you notice this,then .........

Its plugged catalytic converter from here,I would have the exhaust backpresure tested to see f it is plugged,it shouldnt be any more then 1.5 psi of pressure through idle to full throttle.Another tell tale sign of a severe plugged cat is to check the heat from the cat after running the engine,both the inlet to the cat and the outlet side of it should be very close to the same temp,if the front inlet side of it is hot but the rear is allot cooler then it is plugged.

This details will help you to confirm.

Thanks.