bad MAF? 93 2.3L

[yonu]

ok the basic issues horrid acceleration(have had the truck 8yrs and just started), 4th and 5th are no use even just to keep speed on highway(just started), rough idle all over the board one time it may be 1200 the next 200. Bassicly just running like #@!#.

Yonu

 

[RonD]

Cold idle should be 1,200
Warm idle 750-800 with automatic, 700 with manual

If idle is not stable warm then unplug IAC valve wire, this will close it, and idle should drop to 500 or engine may even stall, either is OK it means no vacuum leak.
If idle stays high you do have a leak somewhere.

Low power is either low compression or incorrect air/fuel mix
When was timing belt last replaced, this controls compression?
Compression test would tell you right away if this is the problem or if it isn't so look elsewhere.
You do need to remove 1 spark plug from each cylinder and then do the test.

The rest of the issues are a bit harder to test for.
You can remove the O2 sensor and then test drive, this would eliminate exhaust blockage as the problem, but very loud

With Cold engine computer doesn't use O2 sensors to adjust air/fuel mix, EGR is also not used cold, so if engine runs better cold could be issue with one of these.

Fuel system needs pressure and volume, pressure can show good but lacks enough volume for high demand, load.

 

[yonu]

Ok timing belt was changed about 18months ago.

Yonu

 

[yonu]

it will idle since I replaced the TB vacuum line.

Ok I have not done a compression test yet but I did get a chance today while the engine was warm to try unplugging the IAC and it makes no difference in the way the engine runs it never idles down once warm it stays right at 1100rpm. Any thoughts?

Yonu