stuck intaKE valve? 88 Ranger 2.3 L "broken rocker arm"?

[NID_FTL]

I am getting spark and fuel injector signal to #3 cyn but no combustion, wile running I can pull plug wires 1,2 and 4 and causes engine to stall but when I pull #3 I notice no diffrence in the running Idle at all, this isolates it to cyn #3 so I did a compression test and it tested at 120 lbs
could a condition exist that allows you to get normal compression yet not allow air intake for proper combustion? like a stuck intaKE valve?

gonna try to see if it's a broken rocker arm maybe a broken retaining pin or ring? anyone have a clue what I am looking for? will it be obivous?

I am delaying pulling the head and cam as a unit and taking it to have it machined, I have limited funds so really trying to fix it myself. by bicycle I have most parts stores withing a reasonable distance. I know I can do this, any help will be a life saver Jimbo....

 

[Mark_88]

I just posted an answer in your other thread...but this could be a plugged fuel injector...remove the third plug wire and run the engine...then remove the plug to check for fuel...if there is no fuel on the plug the injector is the problem...


Also...did you remove the valve cover to check the valve stems for movement? If they are moving like the rest of them I'd say the problem isn't a stuck valve...

 

[NID_FTL]

#3 is a brand new injector, and noid indicates a pulse, plug is new and is getting good spark. is fireing on 3 cyn's only by my figureing. oh and yes 120psi on compression test, do not have equipment to do leak down test at this time.

 

[NID_FTL]

"As for the stuck valves...that's possible...more like damaged valve stem...did you remove the rocker cover to check for movment in the valves?"

is the rocker cover the valve cover? I can see the cam, rockers look clean and no sign of damage. I have not untightned the timming belt to rotate by hand the cam, as of yet. but seems that is next.

 

[NomadRider]

#3 is a brand new injector,

Could be a bad new injecter. New doesn't always mean working.

 

[NomadRider]

You shouldn't have to loosen the timing belt. Find a socket that fits the nut on the crankshaft pulley and use a ratchet to turn the engine over.