Just the other day i finished changing the head gaskets on my '85 and reassembled it according to the book (haynes). Now the engine will just fire one or two cylinders and die. I've tried adjusting the distributor and the timing and still have no avail. All cylinders have spark and fuel. Any suggestions?

 

Check#5 and 7. They are often crossed up. Tripple check the firing order. More than a few times, i have goofed this up. Check the connector on the maf. Also check the fuel pump fuse, and also the fuel pump relay connector. Relay is located next to wiper motor.

 

If it is only firing on one or two cylinders, double check your valve adjustments. If you over tightened some of them, then, those valves could be hanging open and not allowing any compression to build.

RACE ON!!!

 

The firing order is fine, along with fuel delivery, i'm getting very sparatic combustion but it dies right away. I suspect that my distributor is off alignment with my number one cylinder but i've redone that twice already and to no avail, is there anything that would cause complete failure like that, maybe my valve adjustment?

 

And for the valve adjustment, i tightened one full turn after 0 lash as haynes said, but then i read on a thread that 1/4- 1/2 turn is plenty. Also should i only adjust when that cylinder is at tdc?

 

In order to eliminate any chance of mistake, I adjust each rocker seperately. I roll motor over until the valve completely opens and then closes. Then I roll the motor a bit more and adjust. Takes a bit longer than following the firing order, but worth it imo.

 

Just to make sure i did it right can anyone give me a link or something for a good way to adjust the valves im beginning to agree that my valves are way outta whack

 

As long as you are on the base circle of the cam, adjusting is simple. I do not have a link though.

 

here are some thoughts on lash setting grabbed from a Search here on the CF, etc. from your fellow CF members. You can do a search and get even more help!
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OK, first think of valve timing:
-the exhaust valve is still open when the intake valve begins to open
-when the intake valve begins to close the exhaust valve is fully closed
-when the exhaust valve begins to open the intake valve is fully closed

This leads to the EO/IC method of finding zero lash:
-rotate the crank till the intake valve begins to close and set zero lash on the exhaust valve
-rotate the crank till the exhaust valve begins to open and set zero lash on the intake valve

I've found that when I twirl the push rod between thumb and finger as I slowly tighten the rocker nut the diffference between very slight resistance and hard resistance is only 1/8 turn. So I set zero lash and then tighten an additional 5/8 turn. This assures that lash is set to 1/2-3/4 turn, which is well within limits on positioning the lifter plunger midway within the lifter body (this is what setting lash is all about).

Remember that each cylinder hits TDC TWICE - once on the intake cycle and once on the exhaust cycle. Make sure you're adjusting the right rocker at the right time. I made that mistake and it seemed like they were getting loose when they had just been tightened...

Begin with any cylinder you want. Rember to stop turning the crank...."As-Soon-As"....you see one of the pushrods begin to move. This is key to remember.

OK, here we go: EO = Exhaust Opens. IC = Intake Closes.
Lets say, you start moving the crank (pick a cylinder).... now keep turning the crank and watch for the intake's rod (for example) start to close. As soon as you see the slighest movement of the, "Intake Close" (IC)...STOP!
Now set the exhaust pushrod to specs. Say the adjustment calls for one full turn (stock adjustment) from zero play. Without making too drastic of a move to unseat the rod from the lifter, start moving the pushrod up and down. Keep doing this until there is just the slightest up and down movement. Then, begin spinning the pushrod as you keep tighten the rocker nut. When you can no longer spin (a subtle touch as you tighten very slowly) the rod, stop.
Place the wrench at a known starting point, and turn the rocker nut 360 degrees... and stop. One full turn is a standard adjustment for a stock engine. Consult with the "performance specs" of their adjustments. It might be less or more turns....depending, etc. Solid lifters on the other hand, will take a different adjustment approach.

Now turn the crank, and watch for the exhaust just begin to open (EO). As soon as you see this happen, STOP! Set the intake valve to specs in the same manor stated above. You've completed an adjustment of one cylinder. There are 7 more to go. This is a lot quicker and more accurate (bottom of heel) than finding TDC of each cylinder. Hope this helps.


Be sure that the spring in lifter has enough time to return the plunger to the top before you adjust that valve. I tried this method when I installed my 1.6 rollers and LT4 springs. I did the install after my car sat for weeks and when it came to start up they worked perfect from the get go. I haven't had to mess with them yet. This method may seem more work than its worth but it positively puts the lifter on the heel of the cam.
Valve Adjustment The Quick Way:
Ok, now to the good stuff! First, view this little chart for Small and Big Block Chevy Engines that I made and see if you can understand it ... for other engines, use your firing order that matches your engine to do the same. You set up this procedure based upon "opposite" cylinders of your firing order. (see below)
Intake Valve Adjustment: ENGINE OFF!

with #1 cylinder Intake Valve at full valve lift .... Adjust #6 Intake Valve
with #8 cylinder Intake Valve at full valve lift .... Adjust #5 Intake Valve
with #4 cylinder Intake Valve at full valve lift .... Adjust #7 Intake Valve
with #3 cylinder Intake Valve at full valve lift .... Adjust #2 Intake Valve
with #6 cylinder Intake Valve at full valve lift .... Adjust #1 Intake Valve
with #5 cylinder Intake Valve at full valve lift .... Adjust #8 Intake Valve
with #7 cylinder Intake Valve at full valve lift .... Adjust #4 Intake Valve
with #2 cylinder Intake Valve at full valve lift .... Adjust #3 Intake Valve

Exhaust Valve Adjustment: ENGINE OFF!

If you have noticed, this is the same procedure as the intake valves listed above, just that you are now adjusting the exhaust valves the same way.

with #1 cylinder Exhaust Valve at full valve lift .... Adjust #6 Exhaust Valve
with #8 cylinder Exhaust Valve at full valve lift .... Adjust #5 Exhaust Valve
with #4 cylinder Exhaust Valve at full valve lift .... Adjust #7 Exhaust Valve
with #3 cylinder Exhaust Valve at full valve lift .... Adjust #2 Exhaust Valve
with #6 cylinder Exhaust Valve at full valve lift .... Adjust #1 Exhaust Valve
with #5 cylinder Exhaust Valve at full valve lift .... Adjust #8 Exhaust Valve
with #7 cylinder Exhaust Valve at full valve lift .... Adjust #4 Exhaust Valve
with #2 cylinder Exhaust Valve at full valve lift .... Adjust #3 Exhaust Valve

Need an explanation?

Well, what you have here is "opposite" valves on the engine cycle. The small and big block Chevy engines use a firing order of 1-8-4-3-6-5-7-2. What you do is separate the order into the two sides of the firing order. These are "exact" opposites that put the opposing valve at the correct location for adjustment, meaning the back side (base circle, or heal) of the cam lobe (see image at left). This procedure works on most V8 and V6 engines. (base circle, or heal) of the cam lobe (see image at left). This procedure works on most V8 and V6 engines. (base circle, or heal) of the cam lobe (see image at left). This procedure works on most V8 and V6 engines.

1 - 6

8 - 5

4 - 7

3 - 2

If the lifter is anywhere other than on the heal of the cam where there is NO ramp contact you will have incorrect lash. The chart above makes sure you are on the backside of the cam lobe. When the cylinder is at TDC, this is not often the correct location to get the proper lash setting.

 

The question isn't whether you adjusted a 1/4, a 1/2. or a full turn beyond zero lash. The engine will start in any of those cases. The question is, if you made the preload adjustment (a 1/4, a 1/2. or a full turn) from a true zero lash, position. Two conditions can frustrate finding zero lash.

The first is starting out with the lifter somewhere other than the base circle of the camshaft. Your question, "Also should i only adjust when that cylinder is at tdc?" gives me concern over where you started out to establish zero lash.

The second, is in recognizing when "zero lash" is attained. By definition, "zero lash" is just at the point where all the "play" has been removed from the valve mechanism for a given valve, and before any "preload" occurs. Some instructions say to spin the push rod until it no longer spins, and that that is the point of zero lash. Others say that when you feel resistance to the spinning, you have reached zero lash. Both instructions are flawed. If the spring in the lifter, under the plunger, isn't very strong, you may be able to easily spin the push rod beyond the zero lash point. Likewise, you may not feel the resistance in the spinning of the push roduntil you have passed through the zero lash point. In either case, you will feel the resistance when the plunger has bottomed in the lifter with ALL the preload removed. At that point the valve train for that valve is stacked solid. Any attempt to "add preload" at that point is pushing the valve off of it's seat, to where it CAN'T close.

The point of zero lash is easiest to identify for those who are unpracticed, is to juggle the push rod up and down, between the rocker arm and the lifter. When tightening the adjustment removes all the free-play (the push rod no longer jiggles) you are at the point of "zero lash". You can set your preload whether, 1/4, a 1/2. or a full turn, from there.

RACE ON!!!

 

Its very possible that you have the distributor in backwards, 180 degress out of phase. This happens more times than you can imagine anmd its the simplest to fix.

mrmuzic

 

ha problem solved... the dist was out of phase. Next problem... the car won't idle. I can get it to start (roughly i might add), but wi th a lil gas it will run decently, but the second i ease of the gas it clutters out and dies. The funny thing is the iac (idle air control) makes a funny sparatic clicking when i turn the ignition off, and when i try to run a trouble code, it quickly clicks and doesnt stop until i pull out the paperclip, yet it throws no codes. Should i replace the unit anyways or is something else to blame.

 

TDC on the compression stroke, yes.
The BEST way is to get them adjusted static (engine off), then remove a valve cover and install oil control clips to the rockers. Start the engine and starting at the front, loosen the first rocker until it just starts to chatter, then slowly tighten it until it just stops, now go 1/2 turn more. Repeat this for all valves. You now have valves that you KNOW are properly adjusted.

 

Here's how to adjust the IAC and base idle.
https://www.corvetteforum.com/techti...D=55&TopicID=2

Try adjusting it instead of just throwing money at the problem.

Note:
The article leaves out the fact that you need to have the EST connector unplugged while you do this. It's the same one you have to unplug while you adjust timing with a timing gun. It is located on the firewall between the brake booster and the driver's side valve cover.

You might also want to do what some guys here do when doing this adjustment. That is to begin with a higher idle speed and adjust it down. The tech tip calls for starting with a low idle and going up in idle speed. This will keep the car from dying on you during adjustment.

Now, if you rotated the motor at all while you had the distributor out, your distributor timing will no longer be "set" at any aligment marks you may have made before removal as the Haynes manual would have suggest you to do. So if you are simply re-aligning it to any marks you may have made, and you did rotate the motor any ammount with the distributor out, the timing will be off at these markings. Set it with a timing gun if you are not doing that.