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engine won't start after valve adjustment

33K views 19 replies 10 participants last post by  PCPete 
#1 ·
I just got done doing a valve adjustment on my 350. It has hydraulic lifters. I looked around and ended up going with the method on hotrodders.com. Here's the link: http://www.hotrodders.com/forum/best-way-adjusting-valves-sbc-132599.html post #6 by "Frisco". I've had it in the car and running fairly decent for about 6 months now. I've probably driven it around 30 or so miles total. But it ran pretty good. I noticed what I thought was excessive valvetrain noise, so I figured I'd go through and make sure all the valves were good. Going with this method, they all needed to be cinched down a little. After the adjustment, it won't run. It turns, but it doesn't fire at all. All I did was take the slack out of each valve in the described method from that post. What might have gone wrong?
 
#2 ·
By you tightening the lash, or the noise out of it, the valves are probably not closing all the way and not making any compression. You only put about 30 miles on in six months? Sounds like me driving my car. Have you put a compression gauge on it? It's possible that you started to eat the cam and that was the extra clacking that you heard. If you do a compression test, it will show if you have compression. How much did you have to tighten them to quiet them up? Also, if the rockers don't move up and down much, could be the cam. Dave
 
#3 ·
I'm sure the cam is fine. The rockers travel plenty as I spin the engine. I'm looking around elsewhere online right now and I think I over-tightened. Seeing it didn't even start, does that mean I didn't hurt my engine? Or could I have done some serious damage? Anyone have a better method than the one I used? I need to get this thing right already.

And yes, 30 miles in 6 months.:eek: I've been steadily working on other areas of the car and haven't been driving it more than a couple miles at a time after each time I tweak or replace something.
 
#4 ·
Set intake when exhaust starts to open. Set exhaust when intake almost closed. Now loosen adjusting nut then tighten back while rotating pushrod till you feel slight tension there your zero lash tighten another half turn your done ! Yeah somebody will probably say chiltons says full turn but I never go full turn! Jmo!!
 
#6 ·
I did 1/4 turn when I felt tension while rotating the pushrod. Apparently, that was too much. I went back and checked; No compression in cylinder 1 when I spin the engine. I adjusted them in the exact order of that post on hotrodders. Maybe I just went too tight? Or is that guys method no good?
 
#5 ·
Here's what worked for me... Rather than spinning the pushrod and attempting to get the correct 'feel', hold the pushrod between two fingers and lift the pushrod up and down while slowly tightening the adjustment nut. When you reach the point where there is no more up and down movement you will be at 0 lash. Tighten an additional 1/4 to 1/2 turn. I did this with a cold motor and all valves adjust correctly.
 
#7 ·
It might be a coincidence something else died that is causing the engine not to fire. Lifters need to be a long way off not to even sputter or try to fire. Check for spark and fuel and go from there.
 
#8 ·
The method I mentioned is how crane cams recommends I've used this method for years without a problem done a cylinder at a time is a little less confusing also is good to let lifter sit for a few minutes after loosening to allow the retainer to seat back into a neutral position against the lock.
 
#11 ·
It did sound weird when it cranked. I assumed this was due to the valves being off after adjustment. I know that I have fuel. Maybe I managed to knock the wire loose on the distributor when I was moving the plug wires around. I give up for tonight. I'm both disgusted and disappointed...and drinking now. I guess I'll go back over to the garage tomorrow after work and see what I did wrong. I really wish I had internet over there so I could look this stuff up on a real computer instead of my phone. Oh well, I'm going to finish this beer and go to bed. I give up on the Nova for tonight.
 
#14 ·
Just an idea... have you checked to see if it will start w/o the valve covers on? Sounds crazy but hear me out. A pal of mine years ago was just getting into fixing his own stuff and decided he would change the valve cover gaskets on his 72 short wheel base Chevy. After he finished.... no start. He panicked and called me over. I look at it... offer my condolences.... then offer to buy it just for the body... 500$... (he had paid 1500 3 months before). I then tell him.. look at the wire going to to coil.... he had pinched it between the valve cover and head grounding it out causing the no start. I loosened the cover pulled the wire out taped it up and started "my" new truck... I "sold" it back to him for a cpl of cold ones while we talked... Just an off the wall idea that might help... good luck
 
#15 ·
It cranks, just doesn't fire. No pinched wires. I just screwed up the adjustment pretty bad. I had strong compression in the number 1 when I turned it to TDC. After the adjustment, no compression. So I need to go back and do it over. How can I bled the oil out of the lifters?
 
#17 ·
Good news. I got back over to the shop today and started over. This time I used the "up/down" method rather than turning the pushrod. I also went 1/8 turn rather than 1/4. As soon as I started to turn it over, I could tell it was fixed. After I fired it up and warmed it up, it ran better than ever. No more valvetrain noise, and it ran nice and smooth. I'm happy. Now I can focus on the other countless projects to get the car where I want it.:D
 
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