99 s10 misfire

[rkingon]

Hi, I have a 1999 Chev s10 with the 2.2 liter. I'm having a HUGE hesitation problem, especially when trying to go up hills at a "average" speed. If i floor it, everything is fine. or if I'm going slow everything is ok..

I'm not pulling any codes, MIL is not on.

I went to the misfire datastream with my computer and Cylinder 1 is misfiring BAD. All other cylinders have 0 misfires. When power braking I'm getting up to 170 misfire counts. Vehicle shakes like crazy.

So far I have replaced:
-Plugs(Platnum)
-Wires/Boots
-TPS Sensor
-MAF & MAP Sensor
-Cyl 1 Fuel Injector
-Coil Pack(x2)
-Fuel Pump & Filter

I'm starting to think that I have a malfunctioning computer.. It's weird how it will only do it at a certain rpm range. lower/higher and everything is fine.

I've ruled out the CAT considering it's only at certain rpm and the crank/cam sensor since it's only misfiring 1 cylinder. Really that rules out half the things i changed, but I changed them before I found out it was only misfiring on cyl 1.

Anways.. any help would be greatly appreciated.
THANKS!

-Roi

[MT-2500]

AC Delco Plugs?
Good hot blue spark to all cylinders.
Check for good hot blue spark to no 1 cylinder after it wasrms up.

[rkingon]

yes, I have tried ac delco plugs, along with bosch platnum 2+ plugs..

I've changed cyl 1's plug 3 times now. first with ngk, then ac delco, and now im running the bosch. I also tried taking the ign wire from cyl 2 and using it for cyl 1. misfire stay'd on cyl 1. swapped coil packs aswell. moved the 1-4 coil to the 2-3 coil spot. no luck there either.

What else could it possibly be?!?! =/

[MT-2500]

Have you checked for good spark to it?
Have you checked compression?
Have you checked for injector pulse to that cylinder?
Is the plug wet or dry when you pull it out?

[rkingon]

Yah, good strong spark. did compression test. 145psi.
@ idle injector pulse is at 3.5 and WOT goes up to 11.5

plug was dry and actually looked pretty good when i pulled it. didn't look as if it were running lean/rich