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mafiacustomz 05-02-2012 07:15 PM

403 olds again
 
im still working on a 69 leman with a 77 403 old motor i have a 600 cfm holly elec. chock and im running a 5-9 psi elec. fuel pump push style not pull. This motor will not fire it has spark it has fuel and all the air it can get still wont fire. I have tried changing the firing order clockwise, counter clockwise, advance timing, retard timing, and any other way it can be done wont fire any one know what i can do even had gas shooting out of the car overflow wont fire.

BOBCRMAN@aol.com 05-02-2012 08:47 PM

Ist find no.1 cyl. Then determine the dist rotation. Remove no.1 spark plug. slowly crank engine with your finger over the spark plug hole. compression will blow against your finger as the timing mark comes up. This will be TDC no.1 fire.

No.1 spark plug wire to this plug. then 1 8 4 3 6 5 7 2 in the direction of rotation. gas, ignition, compression- start..

mafiacustomz 05-02-2012 09:06 PM

yep done all that still no start

FmrStrtracer 05-03-2012 03:39 PM

Distributor rotatation is counter-clockwise, 18436572.

Have you done a complete compression test on all 8 cylinders to make sure you have a viable motor.

Are you using a fuel regulator and gage to set fuel psi to 6psi, no higher.

You say you have spark, where are you testing for spark. Is it a strong spark.

What distributor are you using? If its an HEI, are you supplying a full 12 volts to the distributor. If you are using the Lemans supply line from the starter, it is a resistor wire only supplying 9volts or so, to low for the HEI.

Are you sure you have no torn or misplaced carb or intake gaskets. This will cause what is known as a "Vacuum leak". The engine will draw air thru this "leak" instead of thru the carb, so you will get no fuel into the cylinders.

What intake are you using, the factory intake will require an adapter to run a Holley square-bore carb, with out the adapter you will have a huge vacuum leak.

Just a few things for you to check. Let us know what you find.

LATECH 05-03-2012 05:33 PM

Those olds motors are notorious for jumping time at the timing chain.maybe you should be checking that next.

FmrStrtracer 05-04-2012 03:49 AM

Quote:

Originally Posted by LATECH
Those olds motors are notorious for jumping time at the timing chain.maybe you should be checking that next.

Yes, GM loved that nylon coated timing gear. Ford used them too. made for a quieter running motor. But...

mafiacustomz 05-04-2012 10:45 PM

as far as i can tell the motor did not jump time.

i do have a square bore with the adapter plate.

it is hei and running 12 volt.

spark is blue and i check all 8 plugs for spark.

the fuel pump runs 5.5 - 9 psi i was told i dont need a regulator by auto parts store.

im using the stock intake their are some vac lines broke and not using i will plug them.

ive check timing and firing order all the time seems right but cant tell becouse its not right on 1 its befor (facing water pump) or after (facing battery) from the hexagon distributor gear on them cars that suck.

I also cant seem to get gas to the #1 cylender like the motor is slanted to far back but its not.

FmrStrtracer 05-05-2012 02:48 PM

Quote:

Originally Posted by mafiacustomz
the fuel pump runs 5.5 - 9 psi i was told i dont need a regulator by auto parts store.

im using the stock intake their are some vac lines broke and not using i will plug them.

I also cant seem to get gas to the #1 cylender like the motor is slanted to far back but its not.

If fuel pressure is above 6.5 you need regulator, dont care what the autoparts store said.

All vacuum leaks must be fixed or plugged.

Fuel is drawn into the cylinders in a mix of air and fuel, it does not run to the cylinders by gravity. If you have liquid fuel in the intake, you have too much fuel.

mafiacustomz 05-10-2012 02:59 PM

ok im going to get a regulator to solve that problem but i found the real problem it did infact jump time it should be cam gear at 6 oclock and crank gear at 12 oclock the cam is at 6 and the crank is at 2 so it jumped quite abit.

I would like to know if i take the crank back to 12 and thin put the new timing chain and gears on putting the cam at 6 will it be in time or am i going to have to find out if im on compression or exhaust stroke its hard to tell when the motor is still in the car for me any tricks.

LATECH 05-10-2012 04:40 PM

How bout it... :thumbup:

mafiacustomz 05-10-2012 04:54 PM

what a dumb design for a timing set i can almost push the chain into the gear set LOL.

Mr. P-Body 05-10-2012 07:30 PM

Actually, the dots should be both at 12 o'clock (compression, no. 1).

There are several good brands of roller chain sets out there. Highly recommend you replace the old "silent" chain with a modern one. The better ones have indivdual and seamless rollers, .250"diameter. No need for the billet gears with a mild or stock cam.

Jim

joe_padavano 05-11-2012 04:41 AM

Quote:

Originally Posted by Mr. P-Body
Actually, the dots should be both at 12 o'clock (compression, no. 1).

There are several good brands of roller chain sets out there. Highly recommend you replace the old "silent" chain with a modern one. The better ones have indivdual and seamless rollers, .250"diameter. No need for the billet gears with a mild or stock cam.

Jim


Actually, either both at 12 or one at 6 and one at 12 is the same. Cam turns at half crank speed. Olds engines are noninterference, so valves should be fine.

Mr. P-Body 05-11-2012 07:07 AM

Joe,

Sorry, but this a common misconception. When the "dots" are at 12, #1 cylinder is "up" on compression. When they're "dot to dot", #6 is 'up" and #1 is on "overlap". Remember the piston is at TDC twice during the 4-stroke cycle. TDC "compression" is the key, as you can now place the distributor in "by the book" AND adjust the valves (if necessary) via the "firing order" method (most effective method).

Jim

cobalt327 05-11-2012 05:25 PM

Quote:

Originally Posted by mafiacustomz
ok im going to get a regulator to solve that problem but i found the real problem it did infact jump time it should be cam gear at 6 oclock and crank gear at 12 oclock the cam is at 6 and the crank is at 2 so it jumped quite abit.

I would like to know if i take the crank back to 12 and thin put the new timing chain and gears on putting the cam at 6 will it be in time or am i going to have to find out if im on compression or exhaust stroke its hard to tell when the motor is still in the car for me any tricks.

Use the cam gear to turn the cam so the dots are closest to each other (cam gear at 6 o'clock, crank gear at 12 o'clock)- this makes aligning the dots easier/less chance of an error.

With the timing set in this position (cam gear at 6 o'clock, crank gear at 12 o'clock), cylinder #6 will be on compression. You can set the distributor in with the timing gears in this position if you point the rotor towards #6 distributor cap terminal to set the ignition timing.

Or, rotate the crank one revolution (timing marks are now at 12 o'clock for the cam AND crank gear), then point the rotor towards #1 distributor cap terminal to set the ignition timing.


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