you can have bad gas from reversion....

also the S10 if it had a V6 4.3L engine is much more powerful than the 4.9L-I6

more power, more torque and lots lighter so it is common for an S10 to whip a full size truck...

once you find the issue it will run much better...

 

well i took off the upper part of the intake manifold and it looks like t heir is a like film of oil built up on the inside. how would i clean this out? and it actually looks like around 5&6 that their is oil built up on the intake gasket. so im almost thinking it is maybe the valve seal leaking oil into the cyl. im going to take off the valve cover and take a look at the rods and rockers.

 

the only way is to pull the whole intake and use brake-clean and do it that way...

that maybe from the PCV system though...so I would check that as well...make sure the valve is good..if it gets stuck it will suck oil into the intake...

when you pull the valve cover manually rotate the engine and look at the cylinders in question...the rockers should swing in the same position....shouldnt be any lower on the stop (base circle of the cam) or during lift...

 

well i took the valve cover off and on cyc6 rockers it looks like carbon build up and starting on cyl5. and all the other rockers are smooth with oil. ill post pics i got. what would this mean? bad valve seal?

 

once you have the intake off pull the exhaust manifold if you can...look at the valves..if it is burning oil it will be on the backsides of the valves pretty heavy...cabon build up on the rockers can mean several things..if it is only on those cyclinders and the others are fine it means those cyclinders are hotter than the others and the oil is actually cooking on the rockers....creating the carbon....

did you find anything rotating the engine...a valve nesting lower than the others..? a valve achieving less of a lift than the others...? this is what you want to look for..this will indicate a collapsed lifter of other things...

 

in the process of getting the front exuast man. off. the intake is pretty carboned up to the head. so i will look at the valves when i get those off. so i will clean the intake and probably put some headers on from summit racing. and the end of the injectors are carboned up by the o-ring. is their anyway to test these?

 

well i got the manifolds off and it looks pretty carboned up inside but the vavles have no carbon on them. so im eaither guessing it could have been the injector. or posibly the fuel was puddling up in 6 cause 6 looked like the carbon was closser to the valve then the other cyl's. and about the headers i dont know i looked at the year and cant seem to find any for my year.

 

I've been lurking in the back ground following your problem in this thread. I was wondering why a bad sensor, or bad computer where never really suspect for a cause of the problem. Incorrect fuel/air could seem like a motor missing. Your getting into this motor pretty deep, I hope that you can get her going again soon.

 

very rarely will it be a bad ECM and/or sensor..as long as the conection are good especially on the grounds the sensors should outlive the truck....

although some do go bad it can be related to a bad connection that has caused it....

even then it would be on all cylinders and not just one or two