Broken Camshaft? Bent Valves?

[nddenise]

Broken Camshaft? Bent Valves?
Timing chain replaced, perfectly in time. Replaced fuel pump and relay working, when you turn it over it's still backfiring thru the throttle body. All the valves appear to be working when you try to start it then when it's sitting there are 7 of 8 rockers are loose.
Input appreciated!

 

[melsg5]

Go back over how the timing chain was installed. Make sure the marks are correct and it didnt skip. Were all tensioner components replaced and installed correctly.

 

[nddenise]

Yes the timing chain was perfect, removed the head to see the pistons to make sure they were tdc. Tensioner and everything replaced. Have never had this problem with a damned vehicle! I am pretty sure it jumped time again so all I can think is broken camshaft!??

 

[melsg5]

Can you turn the crank with a socket/wrench and see if the rockers move?

______________________________

 

[nddenise]

yes we can turn the car over and see the rockers working but i don't think they are working properly.

 

[melsg5]

did you set up the crank and cam gears as illustrated in this link?

http://www.jasperengines.com/pdf/GM2.2TimingTB.pdf

 

[nddenise]

Yep set up just like that. I even put a small dowel rod on top of the piston thru the spark plug hole then i turned the crank slowly with a wrench to make sure the valves and pistons were all in time and it appeared to be perfect. TDC.

 

[melsg5]

all the rocker arms are torqued to 21 ft/lbs?

______________________________

 

[nddenise]

The car was going down the road at 70 miles an hour and it just died. I haven't touched the rockers they should have been fine. The chain tensioner busted and that's why it jumped time.

 

[melsg5]

well you are stating the rockers are loose or not moving much so either the nuts for the rockers are loose or the camshaft/lifters are worn or you have valves stuck in the open position because they are bent.

 

[nddenise]

That's what he was afraid of the rockers are all tight he checked it.....they move up and down but he was afraid of bent valves. He is going to do a compression test on it that should tell the truth correct?

 

[melsg5]

yes that would do it

______________________________

 

[nddenise]

Thanks, we will keep you posted will do the compression test tomorrow..

 

[EL TATE]

Thanks, we will keep you posted will do the compression test tomorrow..

At the risk of sounding ignorant, did you verify that you weren't TDC on the exhaust stroke vs. compression stroke?

 

[nddenise]

He did a compression test and as he suspected only one of the valves were actually working. Three of the 4 were bent. He tore it apart and is in the process of replacing all the valves intake and exhaust and all the gaskets as well as the oil pump. Thanks for all your input and I will let you know when it's up and running. He has one more valve to seat and will start the process of putting it all back together again tomorrow.