I just rebuilt my '86 z28 and will not start it fires a few times and then dies. i put a new cam, intake, carb, and headers on.i also hadthe heads milled.it was a stock motor to begin with. i have tried adjusting the timing and it does fire better but still will not stay running. all timing marks are lined up. any ideas? Thanks

Luke

 

What procedure did you follow when you did your initial valve/rocker arm adjustment?
I would look at that first. The procedure as shown in a Chilton's repair manual etc., really sucks at best. Do it this way instead:
http://www.centuryperformance.com/ad...h-spg-149.html

 

i tried the way you sugested to adjust my rocker arms it still will fire but wont run. any more ideas?

 

I looked at that link and My chilton's gives the same procedure with the exception of 1-1 1/2 turns instead of his 1/8-1/2. But if you measure the thread pitch of the stud and go by his .030 it will take 1 turn to achieve that. Maybe I missed how a 1/8 turn gets that much.

And when you say fire does it start then die or just sound like it wants to start but does not?

 

My old books give the old way with the two position I-E-E-I....procedure which sucks. And I always go 1/2 turn automatically, not 1/8.
Schultzie, when you are adjusting the valves, you want to tighten the rocker nut just enough to take out the lash in the push rod (while wiggling the push rod up and down). Then go 1/2 turn beyond that point. While adjusting, you're not trying to stop the push rod from spinning. If you are trying to stop the rods from spinning as you tighten, then you'll probably be too tight and could wind up with some valves that aren't closing completely. Which way did you do it?
Do you get any popping out of the carb, like it's maybe a timing issue? Or does it just putter out and quit?

 

Yeah that is right. Turn the engine twice instead of 16 times like his explaination with the over exagerated incorrect cam to lifter location pic. Thats all cool for the guys that use dial indicaters instead of torque wrenches and index thier plugs and all but its a lot of unnessary work for every one else.
Oh and when you don't put enough preload on the lifter you are using more of the spring inside to open the valves and it will absorb some of the energy that it needs

 

There's nothing unnecessary about the procedure that I posted, it's a matter of doing it the best possible way. There’s also nothing high-tech about it, needing no dial indicators, calipers, feeler gauges, etc. The whole idea is to adjust each valve as the lifter is on the heel of the cam so that the valves are at absolute close. With the cam's lobes being in all different positions, doing it the two-step way obviously leaves a number of them off the heel. So you need to spend an extra 15 minutes to adjust the valves now to get it perfectly right....big whoop! They're hydraulic lifters, set them once and you're done with it anyway...time well spent in my book.
Go ahead and do it the "easy" two-step way if that’s what floats your boat. Then go back and slowly turn the engine over by hand as you flick all of your lifters to see just how many of them are sloppy again. I guarantee you'll have more than one. I have done it the easy way before, and that was always the result. The two-step method is good enough to at least get the engine running, as long as you plan on doing the final adjustment the messy "engine running" way. But the valve-by-valve way is simply a better "set it and forget it" procedure.

 

I liek to adjust them with the engine running.


Ok, onto your problem. Do you have fuel pressure? Push the accelerator pump on the carb, does it feel right, and do you see fuel spray into the primaries? If thats all good, check and re check your firing order.


To me, it sounds like you have it firing on the exhaust stroke. Find TDC on the compression stroke by removing the #1 plug and placing your finger over it. Unplug the hot wire to the coil and have someone turn it over till your finger pops out, then line up the timing mark. Pull the distributor cap and check if the rotor is pointing to the number 1 cylinder. If not, pull the distributor and correct it.

 

No need to get your panties in a bunch. But the cam does not need to be on its heels to have the valve at absolute close. You can go on using your proven method. I will go on using the more common proven method.

 

They're not in a bunch...hey wait, I don't wear panties...most of the time!!!
Just sayin'...I've tried the other way and don't like it as much because of the bad results.
To each their bone.
Now, what was this post about again? Oh yeah, how's that engine of yours doing shultzie?