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Timing question help

S

sebas54

Member
4.3l merc. I/O
If the timing

4.3l merc. I/O
If the timing isn't set will this cause the engine to not start? I removed the distributor and I am no 100% certain that I reinstlled it at TDC.



Thank you
 
"definitely a no start conditi

"definitely a no start condition, Set #1 cylinder on the compression to TDC.this will be "0" on the timing pointer.remove the dist cap(checking where #1 wire is) and drop dist in with rotor pointing there"
 
"yea that would cause one not

"yea that would cause one not to start
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Place your finger over the spa

Place your finger over the spark plug hole and feel for the compression stroke.
 
"you need to get the mark on t

"you need to get the mark on the pulley at the bottom front of the engine to the ZERO mark on the pointer, The mark will be there 2 times during the #1 cycle (int, comp, power, exhaust) so this will be there when #1 is ready to fire and when #4 is ready to fire, you line it up for #1, put the mark as close to the zero mark on the pointer as you can then drop the dist in with the rotor pointing to where you want the #1 wire to be, tighten enough so you can rotate the dist but not too loose that it will flop around.

If when running it backfires through the carb, your 180 out, simply remove the dist about 1.5" reverse it 180 degrees to point to #4 wire and drop back in, it should then fire properly.. (hope that's clear)"
 
"Thanks, The carb did back fi

"Thanks, The carb did back fire today.

So, I remove the dist. and point the #1 on the cap to the #4 wire?


Is that right?"
 
"No need to remove the distrib

"No need to remove the distributor. Follow this link to find TDC on the compression stroke
http://www.classiccarauto.com/impala/how_to/find_tdc.shtml
When you have the engine at TDC on the compression stroke, remove the distributor cap and see which terminal the rotor points at. Put number one spark plug wire in that terminal. The rest of the wires are inserted in the cap according to the firing order in a clockwise or counter clockwise direction depending on the firing order. Make the final timing adjustment with a timing light. Much of this information can be "googled" from many sources on the net"
 
"Thank you all soo much!!

T

"Thank you all soo much!!

This is what I think I have to do, please let me know if this is right:

Can I turn the engine by hand and put my finger in spark plug hole #1 to locate TDC or loosen the #1 plug and listen to air escaping and check the timimg mark for 0 degrees?

If that works then I install the dist. and have the rotor pointed towards #1 spark plug.

Then I install the cap and take note where the rotor is pointed to put the spark plug wire there.

Then it should start?

Then use the timing light? 8DBTC?


Is this right?"
 
""If that works then I ins

""If that works then I install the dist. and have the rotor pointed towards #1 spark plug."


Just to be clear, the rotor doesn't physically point to the #1 cylinder itself, you plug the number one spark plug wire into the cap where the rotor points. Once again, I dont think you will need to remove the distributor to do this...it's a 5 minute procedure,try it with the distributor in first. If for any reason that doesn't work you can then remove the distributor and try the procedure."
 
after you have the #1 piston o

after you have the #1 piston on top dead center this being with the #1 piston all the way up and your mark pointing at 0deg look at your distributor cap and find #1 wire take your dist cap loose and see if your rotor button is pointing at the number one wire i always take a marker or a awl and mark the dist itself where the number one wire is that way i dont have to mess with cap off and on what they are saying is when the #1 piston is on tdc on compresion then the rotor should be pointing at number one wire on the cap if not take loose and lift and adjust accordingly
 
Thanks to everyone here i got

Thanks to everyone here i got the engine to start.

The engine back fired through the carb?? If I am 180 degrees off would the engine start?

I felt the air push through spark plug hole #1. This can only be felt on the compression stroke? Right?
 
Engine would not start at 180

Engine would not start at 180 degrees off. Recheck the firing order and be sure you have the wires in the correct position and that the cap is on correctly
 
I checked the wires and the ca

I checked the wires and the cap and it will run rough for a couple of seconds then it back fires and stalls.
 
bob is correct engine will onl

bob is correct engine will only backfire at 180 out check your wires for the correct sequence then when its running and warm check timing with a light
 
"Thanks, I got her running by

"Thanks, I got her running by turning the dist.

I was adjusting just a half inch at a time, now this time I turned it about 1/3 and she started right up. Thanks again to all!!!

I will time the egine with the gun once it get darker out


Thanks."
 
"I would just like to say thak

"I would just like to say thak you to everybody on this forum for giving me the encouragment and know how, to do these types of projects. Without forums like this one I would be at a total loss and unable to do what I need.

So, thank you all for a job well done!!!"
 
"Does your 4.3 actually have a

"Does your 4.3 actually have an indicator for timing on the block? Mine (1998)just has a single mark which gives just tdc, and a scanner must be used to final time."
 
"If anyone does have an indica

"If anyone does have an indicator showing degrees for timing on their block, on a 4.3 l, would you mind measuring from tdc to 10 degree btdc and let me know what the measurememtn is? I believe that it's about 7/8", but it would be nice to confirm.
Thanks in advance.

Bob."
 
"Bob, my engine did have the t

"Bob, my engine did have the timing tab but I bought one online. I installed it and line up the harmonic balancer to 8 degrees BTDC."
 
"Sebas.
Did you mean that you

"Sebas.
Did you mean that your engine didn't have one? If you did buy one, I'm assumming that you lined up 0 on the tab to the mark on the balancer, and then timed to 8 degrees.If this is correct, the tab probably has 10 degrees on it. If you could measure the distance from 0 to 10 degrees on the tab, that will be a huge help. I'll just put a mark the corresponding distance away from my tdc, and time to that mark.
Where did you find the tab?
Thank you.

Bob."
 
I think I found the tab at JEG

I think I found the tab at JEGS or Summit but if you do a google search you should be able to find one.
 
Thank you.
You guys are aweso

Thank you.
You guys are awesome!
Have you any idea which one fits the 4.3 L Vortec?
There seems to be 3 or 4 for the short block Chevy (even for the same balancer size).

Bob.
 
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