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View Full Version : Out of ideas....shaking idle, no power, low vaccum



Charles G
11-11-2006, 07:54 PM
Engine has shaked since new headgaskets, but was driveable, now since repairs after accident with deer, shakes worse and no power when put in reverse or drive, nearly entire ignition system is new (DIS, Wires, Crank sensor, IAC) and just put new Motorcraft platinum plugs in as well. My only clue is vaccum at idlle is rock solid 16.5 inches. Tried to find leak with propane and injecting air into engin, found a tiny leak but nothing major. Next plan is to check compression, although heads were pressure checked prior to new gaskets and overheating. Any advice welcome...also repaired grounds which stopped spark and fuel pressure originally, does not appear to be missing, just shaking. Clamped and check all hoses I could find.

bowez
11-11-2006, 08:46 PM
Did valve spring/rockers torque down fully?

tim
11-11-2006, 10:08 PM
I dont know if this helps you but i had a very similar problem and it was a bad lifter.

Charles G
11-12-2006, 09:49 AM
I was told, if you dont touch them no need to adjust them upon re installing heads. but maybe machine shop took apart to clean? Will compression testing tell if rocker arms are not tightened properly?

92sclikenew
11-12-2006, 10:10 AM
prob not because if it wasnt tight it would just not open all the way compresson test will only tell u if it wasnt closing all the way

bowez
11-12-2006, 10:29 AM
I had some carbon get in a valve guide on a Y-block I had to do a head job on (after 1/4million miles and 14years), and valve would not fully close. That was easy to look pull valve cover off and see now on a SC better to do a Compression test. The valves did not come out of that head either just the cleaning/machining and age.

David Neibert
11-12-2006, 10:35 AM
I was told, if you dont touch them no need to adjust them upon re installing heads. but maybe machine shop took apart to clean? Will compression testing tell if rocker arms are not tightened properly?

How did you change the head gaskets without removing the rockers ? Did you remove or make any adjustment to the cam sensor stalk ?

David

Charles G
11-12-2006, 11:58 AM
didnt touch the cam sensor stalk, was able to sneak out push rods without taking rockers off , by rotating rocker arms a little off push rode or as I removed the head. Did this a while backSeems like I would hear loud tapping if rocker nuts were not tightened down enough, just took off exhaust connection to see if too much back up pressure, ran worse and stalled.

fturner
11-12-2006, 12:25 PM
So your saying that when you put the heads back on, you set up the push rods then torqued the head down with the push rods in position :eek: ???

Charles G
11-12-2006, 04:15 PM
I really dont remember for sure, it was more than a year ago, probably put head on, then torqued head bolts then installed push rods. Took valve cover off today and looks like all rocker arms are tightedned down, need to get valve cover all the way off to torque next and do compression test.