My truck will not stay running and back fires after hydraulic valve adjustment.

[Hazieview]

Well I'm back to working on my truck again. I have a new engine and during my tuning process I noticed my rockers were coming loose. I pulled the valve covers and tightened them all down using the 'twist the rod in your fingers method.' Now when I fire it up I can't keep the engine running long enough to loosen the valves to make sure they are not too tight.

So I start the engine and it runs for like 15 second but it sounds like it is backfiring a little bit through the tail pipes. I just need the freaking thing to stay running long enough to pull the valve covers and loosen each rocker to hear the clack and then tighten them back down. I was told this was the best way to set rocker with hydraulic lifters. This is my first time running hydraulic lifters and I'm starting to regret it.

Any help would be greatly appreciated. Thanks!

[BADAZ chevy guy]

Did you rotate the engine at all during this?
Follow this video. The firing order is: 1, 8, 4, 3, 6, 5, 7, 2
It sounds like you've got some of the valves to tight.

https://www.youtube.com/watch?v=89o5rLpbCgI

[Krwright]

You have the valves too tight most likely. Try this first then adjust running.

Adjusting Valves
Small Block Chevy
Get #1 to Top Dead Center

Exh.- 1 – 3 – 4 -8
Int.- 1- 2 – 5 - 7
Get #6 to Top Dead Center

Exh.- 2 – 5 – 6 – 7
Int.- 3 – 4- 6 - 8


You will only turn the engine 2 times. TDC #1 and TDC #6

[Hazieview]

Yes, I did rotate the engine when I adjusted the valves. I think I probably got some of the valves too tight too. However, I was told the best way to adjust the valves was with the engine running. Heck I just need it to stay running long enough to adjust the rockers.

[BADAZ chevy guy]

Originally Posted by Krwright

You have the valves too tight most likely. Try this first then adjust running.

Adjusting Valves
Small Block Chevy
Get #1 to Top Dead Center

Exh.- 1 – 3 – 4 -8
Int.- 1- 2 – 5 - 7
Get #6 to Top Dead Center

Exh.- 2 – 5 – 6 – 7
Int.- 3 – 4- 6 - 8


You will only turn the engine 2 times. TDC #1 and TDC #6

That's what I was looking for. All I could find that was close was the video. Thanks for posting. Now I can save it for another time.

[BADAZ chevy guy]

Originally Posted by Hazieview

Yes, I did rotate the engine when I adjusted the valves. I think I probably got some of the valves too tight too. However, I was told the best way to adjust the valves was with the engine running. Heck I just need it to stay running long enough to adjust the rockers.

I've done valve adjustments both ways. Running and static. I find I get better results from a static adjustment.

[geezer#99]

Don't use the twist method.
Use the wiggle the pushrod method.
Set them to zero lash. No pre-load. Fire it up and then set them running. Use splash clips or slotted valve covers.

[Hazieview]

I always wiggle when I twist...

I just need to keep it running long enough put a timing light on it and adjust the valves. I'm wondering if I can adjust them timing now and maybe it will stay running long enough to readjust the valve lash...?

[geezer#99]

Back all the rockers off and adjust back to zero lash.
Turn the idle up a turn or two.
Loosen the dizzy so it's easy to turn by hand but not too loose.
Get it running and adjust the lifters.
Just back them off till they click and tighten till they don't click.
Do them all like that, then shut the motor off and finish your pre-load at 1/2 turn more.That way your motor won't want to quit if you crank the valve open too fast.

[Hazieview]

Originally Posted by geezer#99

Back all the rockers off and adjust back to zero lash.
Turn the idle up a turn or two.
Loosen the dizzy so it's easy to turn by hand but not too loose.
Get it running and adjust the lifters.
Just back them off till they click and tighten till they don't click.
Do them all like that, then shut the motor off and finish your pre-load at 1/2 turn more.That way your motor won't want to quit if you crank the valve open too fast.

Thank your sir, I will try go ahead and try that out.

[ChevDog1]

Lash is too tight - common problem from trying to use the "spin with your fingers method. I had the same issue when I rebuilt my first small block (almost 30 years ago). Use zero lash as described above.

[bnoon]

I've never ever had to do a running adjustment on hydraulic lifters. Follow manufacturer's recommendation, but usually a quarter to half turn past zero lash... and zero lash means no up/down movement, not a "by feel" type measurement like the rotation method.

[Aaron_L]

I've never had to adjust them while the engine is running either. I was once shown by someone way smarter than me, and pretty well respected in the racing industry. He told me to go 5/8 of a turn past zero lash, and I've had zero problems.

[Hazieview]

I'm beginning to think my valves are fine but I'm not sure. I mean why would my truck run for 15 Seconds and then stop. I wonder if I have something simple going on like a plugged fuel filter or something...? Should be an easy check...

[imjeff]

What caused the valves to get loose? Studs pulling out? Bad capture nuts? I would investigate the cause, fix it, back off the lash and adjust them from zero lash shouldn't need to adjust them running.

Jeff

[Hazieview]

Originally Posted by imjeff

What caused the valves to get loose? Studs pulling out? Bad capture nuts? I would investigate the cause, fix it, back off the lash and adjust them from zero lash shouldn't need to adjust them running.

Jeff

They came loose do to lack of knowledge on my part. I didn't tighten the rockers properly in the beginning. First build rookie mistake. I'm just glad I noticed it!

[gmachinz]

Likely if the valves were too loose at cam break in, then even after you set them now, the surface of the lifters are probably chipped and wasted. Bring them to zero lash, go 1/2 turn past zero lash and you're done.

[gmachinz]

Likely you'll need new cam and lifters-drain the oil....if you see a lot of shiny, you got bad news.