HELP!!!

I have a 93 Sidekick 1.6 16v that is sooo down on power it is not drivable.  Gas milage is down to 12-14 mile per gallon.  I have checked the obvious things first (plugs, clogged converter, O2 sensor).  At first I thought the ECM (computer) was bad.  Had it checked by a reputable rebuild facility and it checked out ok.  Then checked the fuel pressure, 39psi at idle.  According to  Chilton's, this is at the high side of the spec.  Not sure if  this is a problem.  

Is there any way to test the MAF sensor?  The manual does not have the procedure (other than checking for battery voltage with key on/engine off) for '93.

I attempted to have a local Suzuki dealer check the truck out but all they wanted to do was throw parts at it until it was fixed.  I would prefer to fix it myself.

ANY help/suggestions are appreciated.

Rob

When you rev and hold the rpm at around 3000-3500 rpm does the engine smoke black or does it surge or both.

Actually, around 2500rpm it seems to bog down, then above 3500, it revs freely....

Sounds to me like the timing is off.

This souns exactly like the problem I am having, I'm gonna go under the hood some more and tell you if I can find my problem.

AHH I forgot, I had the same problem on an Audi
once, the rubber timing belt was loosing/missing
teeth, timing would slip and the car ran like crap.

CHECK YOUR TIMING BELT, SAVE YOUR MOTOR!!

Nope.  Not the Timing.  Timing belt is in good shape.  Mechanical timing (checked by jumpering the diag port to removed computer advancement)is within specs.

Any other ideas??


Rob

Have I stumped everone???

Have you done a compression test yet?  A compression test will tell you if you have any mechanical problems (valves, timing belt, piston...)  When you pull the plugs, lay them in order and note if there is any differents in them.  Color, damage...  This could also give you a clue what’s wrong.

Assuming your compression is right and you said you have proper fuel pressure check your ignition system.  Maybe you have a weak coil.  Just enough spark to run the engine without a load.

Last note:  I had a EGR valve go bad and it had no power, idled bad and so on...  Also usually if your computer goes bad it won't run at all.  It's a good or bad type of thing.