Thread: my 350 dosent start

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ok ive got a age old problem with new twist....reciently i completely rebuilt a 79 350 corvette ...orgionally an L48 with four barrel carb... i rebuilt a different 350 block of same period except a 4 bolt main instead of a 2 bolt ...all new everything and put new heads on set up for an L82 but that just means bigger valves... i get spark and with the new added on ..inline electric fuel pump i get fuel and i pump throttle on carb and can see gas sqirting into carb ....I followed book to the letter on timing and according to the shop manual crank, cam , and distributor all exactly as they should be timed...

But still no matter what i do the car turns over but will not start... pops a little here and there but nothing..... before the rebuild the carb was rebuilt a year prior so i know it should be still ok ..but to my amazement the OEM block for years had a dead cylinder still ran and previous owner (my father) had no clue so the carb was adjusted to technically a 7 cylinder motor but ran without issue.

So basically everything that says the car should run adds up to no go... not sure exact year of block but same cast number as OEM one...wondering if fireing order changed with in those years or with L82 heads could air fuel mixture need adjustment im not aware of...............any ideas..?... thanks mike

Ok, if you did it by the book and placed the crankshaft timing gear with the dot at 12:00 noon and the camshaft timing gear dot at 6:00 PM with the #1 piston (front of motor, driver's side) at top dead center, then something else is wrong. That something may be that the outer ring on the harmonic damper has slipped on the elastomeric material that is wedged between the outer ring and the inner hub of the damper when it is manufactured. If so, then all attempts at timing the motor with a light will end in failure. It may also be that you have used the incorrect damper for the timing tab that is on the front cover, which again, will end in failure when trying to use a light to time the motor.

Here's how: Toddle on down to Diggers Speed Shop on Lake Street and purchase a piston stop and a degree tape that sticks to the outer ring of the harmonic damper. You'll have to carefully measure the outer diameter of the damper ring in order to purchase the correct tape.

Remove the driver's side valve cover. Remove all spark plugs to make the motor easier to turn. Turn the motor over clockwise at the crankshaft with a long handled ratchet and a socket on the harmonic damper retaining bolt. Have your buddy put his thumb over the #1 spark plug hole as you continue to turn the crank. He'll be feeling air pressure created by the piston coming up in the bore. When he can no longer feel any pressure, turn the crank about another 1/8 turn and stop. Using a marker of some kind, make a mark on the outer ring of the damper exactly at the timing pointer. I've even used a small piece of masking tape stuck to the ring and marked it with a ball point pen. Install the piston stop and screw it in until it barely makes contact with the crown of the piston. Leave the piston stop right there. Do not move it. Go easy and continue turning the crank clockwise all the way around until the piston comes up against the piston stop again. As soon as you feel resistance, STOP. Make another mark on the damper ring at the timing pointer. Now, measure between these two marks you have made on the ring. The exact center between the marks will be TOP DEAD CENTER. Mark top dead center with a pen. Affix the timing tape to the damper ring with the TDC mark on the tape centered at your top dead center mark on the damper.

Remove the piston stop. Rotate the motor through almost 2 more revolutions with your buddy holding his thumb on #1 hole. As he starts to feel compression, you can have him remove his thumb and you can start looking at the timing tape on the damper ring. It will be coming up to TDC. Stop the crank at about 12 degrees BEFORE TOP DEAD CENTER. Do not turn the crank any more. You are done with this part of the operation. REPEAT, DO NOT TURN THE CRANK ANY MORE. Re-install spark plugs.

Remove the distributor. Remove the cap. Pull all the wires off the cap. Straighten out the wires so you can find the longest and shortest ones. Install the distributor with the rotor button pointing to about 6:30 PM. You may have to do this several times, using a long flat bladed screwdriver to align the oil pump drive slot at the oil pump so the distributor will go all the way into the intake manifold so that you can get the retainer clamp on it. Once you have the distributor seated and the rotor pointed to 6:30 PM as you are standing in front of the motor, you can reinstall the cap and start running the wires. Plug in the longest wire at the 6:30 position of the cap and run it to #1 plug (driver's side front hole). Plug in your shortest wire in the next cap hole clockwise and run it to #8 plug (rear hole passenger side). Now, a mid-length wire in the next cap hole clockwise and run it to #4 plug (second plug from the front, pass side). Now, another mid-length wire in the next cap hole clockwise and run to the #3 plug (second from front, driver's side). Now, a mid-length wire in the next cap hole clockwise and run to the #6 plug (third from front, pass side). Now, a mid-length wire in the next cap hole clockwise and run it to the #5 plug, (third from front, driver's side). Now, run a short wire from the next cap hole clockwise to #7 plug (back hole, driver's side). Now, run a long wire from the next cap hole clockwise to #2 plug (front hole, passenger side). Re-install valve cover. Check engine oil level. Check coolant level. Snug down the distributor clamp bolt (leave the bolt just snug so you can turn the housing by hand to adjust the timing). Remove socket and ratchet from crank bolt. Attach timing light. Remove the vacuum advance rubber line from the vacuum advance pod. Plug the end of the line with a golf tee or small bolt.

FIRE MOTOR. Adjust for 12 degrees initial timing with motor idling. Tighten distributor clamp bolt. Replace vacuum line on vacuum pod.

ENJOY.

You're welcome.

i have tried adjustment on distributor ... yes lash is correct ...and timing has been set as good as i can get it still nothing..thats why im at a loss for answers ......set everything as ive always done in the past and nothing works short of taking it to a shop and have them time it and investigate the problems..thanks for the advice ......mike...

HUH.......?

Pull all the plugs,are they all fuel soaked? if so great,at least we're positive fuel is getting there. Disable the ignition and whirl it over a few times to purge the cylinders,now do a compression test to ensure you can sustain fire.If good,clean your plugs,and put back all but no1,leaving ignition disabled,and whirl it overlistening for the rush of air coming out.We're trying to catch no1 just past firing. Now pull the cap and see where the rotor is pointing,up front? the timing is close,Between 9 and 6 o'clock,you are too far out. Hope this helps you ,Hank

Wrong Timming Cover and Balancer will cause not to Start, Because there is Two diffrent Key way Location on the balancer and Two Timming Location on the Timming cover. So Best way is to fine the true Top Dead center by the no. 1 Piston and then check the Top dead cnter on the Timming cover and Balancer. I've seen this case very often.

Let's back up a bit here.......When cam dot is @ 6:00 and crankshaft is at 12:00, you're timed for #6 cylinder on a Chevy. Whith this in mind be sure to re-install the distibutor at proper cylinder. If it cranks, has compression, has fuel, and sparks, it will fire. Lacking any of these will be a no-go. Double check the distributor position and recheck all of the other items needed to fire and you'll have no problems.

Originally Posted by nitrowarrior

Let's back up a bit here.......When cam dot is @ 6:00 and crankshaft is at 12:00, you're timed for #6 cylinder on a Chevy. Whith this in mind be sure to re-install the distibutor at proper cylinder. If it cranks, has compression, has fuel, and sparks, it will fire. Lacking any of these will be a no-go. Double check the distributor position and recheck all of the other items needed to fire and you'll have no problems.

Come on warrior, I know you've timed more than a few Chevys....stop confusing the troops....
Read paragraph 6 here...
http://www.chevyhiperformance.com/te..._installation/
Eyeball the timing dots here...
http://www.rcdengineering.com/install_2.html

Noon on the crank gear and 6 PM on the cam gear with #1 at TDC
Noon on the crank gear and noon on the cam gear with #6 at TDC

Well Richard, you are right about a "few" chevy's coming across my way. Before we get too serious about confusing the issue, Please go back to your RCDENGINEERING.COM article and read paragraph #6. Is states you not only bring the #1 up to TDC, but make sure it's on overlap. The exhaust and Intake being equal on their downward or upward travel. This means it's on overlap and #6 is under compression. Cam dowel at 3 o'clock position with marks being aligned together.

If you're assembling the motor for the first time and just now installing the cam, there will be no compression or overlap or anything else on #1. The piston will just be at TDC with no reference points at all because the cam is not in the block yet to make reference points to overlap or compression. The crank gear dot will be at noon. With #1 piston at TDC, that's when you intall the cam with the cam gear dot at 6 PM. Not until then will you have overlap or compression to refer to.

What they left out of their explanation is that there is no chain on the cam sprocket at this time. They are saying to position the cam gear at 6 PM, then rotate the crank until the crank gear is at noon. Install the chain around both sprockets and nail the cam sprocket to the cam.

That is correct. Now go back to paragraph 10 if the first article you posted. After paragraph six, it leads you to paragraph ten to time the distributor drop in proceedure and states to remove the #1 plug and bump until you feel the compression stroke of the piston in #1. That should point out out that the timing of the dots being together are really not for #1, rather #6. If this proceedure is done with the timing cover off just to be sure where everything falls into respective alignment, you will notice both dots at 12 o'clock and #1 is ready for the distributor. Dollars to dounts, he'll re-drop the distributor and it will fire. (Don't ask me why GM decided to do it that way, maybe a bunch of right brain thinkers on a Friday afternoon when the whistle was blowing)

Here's the verbage:

"First and foremost, the No. 1 piston must be at TDC. Check this by removing the spark plug and placing a finger over the hole. As compression stroke finishes pushing air out of the hole, the piston is at TDC and properly set. Lower the distributor into the engine while making sure the rotor is pointing directly toward the No. 1 spark plug lead. The trick is getting the rotor to face the proper direction while mating the oil-pump drive with the distributor shaft. If necessary, use a long flat-head screwdriver to rotate the pump drive. A few tries and the distributor should mate with the oil-pump shaft and have the rotor facing close to the No. 1 plug lead. With a little timing advance, the engine should easily fire and allow you to set the total timing."

When installing the gears with the crank gear at noon and the cam gear at 6 PM and with the #1 piston at TDC, that is #1 piston firing position. Rotate the motor 360 degrees and both gears will be at noon with the #1 piston at the overlap position and #6 at the firing position. At that point, you could have the rotor at any position you want, as long as the rotor points to the cap position to accept #6 plug wire. This is not where you position the rotor to #1 wire, but to #6. Continue rotating the crank clockwise another 360 degrees with your thumb over #1 plug hole and you'll feel compression because #1 is coming up on compression to fire. That's when you drop the distributor into position to have the rotor pointing to 6:30 PM and run the #1 plug wire from the cap hole closest to 6:30 on the cap.

Your post:
"you will notice both dots at 12 o'clock and #1 is ready for the distributor."
Not for any SBC I ever built. #6 is ready, not #1.

Warrior, I plan to keep doing this until either you understand me or I understand you.

That's cool Richard, If the point we are trying to get across is confusing to the readers and the guy who asked, I go along with your bumping idea for #1 to make sure in his mind and all those who read this to stab the distributor correctly and at least for no other eason, it will fire and he can tme it properly.

OK, with 2 of you saying the same thing, I must be wrong. Sorry Warrior, my brain must have frozen up on me over time. (pun intended). Thanks Denny.

It's okay Richard...Just remember me when I need to pass tech...