Thread: Fixed broken valve spring, Still misfiring heads are off

Like the title says. I changed my broken valve spring that i thought was the problem but Im sill getting a misfire from the same no 5 cylinder. The car sounds a little rough at idle and smooths out when im driving. Seems to have its power back although I didnt want to beat on it too much. speedo was jumping around at some points and one time it felt like my trany was slipping but didnt do it again. If anyone could tell me what might cause this, Im tired of not having my car on the road.

bent valve?

^^That is what I'm thinking...

Like I stated before...rent or buy a borescope and try to check out the piston to see if there is damage there...

Checked the compression.and when i first turned it over i got 80psi then i tried again and got like 60. Third time like 10. Tomorrows another day to try and fix this thing.

I would agree sounds like a bad valve. Pull the heads..

Might as well get head studs while your in there...it makes life pretty easy if it ever happens again...and while the heads are off...get em ported!

So the heads off and the valve looks fine. Gaskets all look fine. What the hell could it be?

Originally Posted by bluegtp91

Might as well get head studs while your in there...it makes life pretty easy if it ever happens again...and while the heads are off...get em ported!

They are ported already

valves are straight and are seating properly. Could it be something else? im almost thinking about putting it all back together and seeing what happens. on a good not i ported my supercharger finally.

Got a lazy injector? Did you test another hole with the compression tester to make sure the compression tester was reading true? I would have also done a Cylinder Leak Down test before I pulled the head..would have told you if you have a valve not seating, bad head gasket/cracked head, excessive ring ware..

What do the walls of the cylinder look like?


Jay

I did try the compression tester on the other cylinder and got about 90 PSI if i remember. The walls of the cylinder look good and when I replaced the spring valve for my broken exhaust one, When I filled the cylinder with air it held it at about 100 psi with no leaks.

I would be looking at an injector problem or coil issue. Try switching 2 coils around and see if the problem follows the coil or stays with the cylinder.

Jay

I did switch the coil and it was still cylinder 5. I havnt swapped the injectors but I did ohm them out and they checked out god. Tomorrow ill be putting her all back together so Ill see if its fixed or not.

pushrod/lifter looks fine?