basic engine questions

[Redrig]

Hey all ,

I have a situation going on with my daily driver that has me going crazy.

it broke down the other day , distributor was toast , the PIP sensor inside it. I get a new distributor and I thought I knew how install a distributor as I have done it a few ties in the past.

its a ford 302 fuel injected bronco by the way.

when I stab the new dizzy , I bring the HB to TDC of piston number 1. stab the dizzy and it will not run , only tried a little bit when cranking (verified fire)

Here is where I am stumped = when I go to check out everything and look over the dizzy , I bring the HB back to TDC of piston one , and my rotor is pointing the exact opposite way from where I stabbed it . Do I have cam problems ? I have never been that deep into an engine before

Or does the cam spin 2 to 1 of the HB ? I know its not skipping cuz I have the dizzy clamped down , I also counted the teeth and its the exact tooth count of my old dizzy and the gears "feel" like they are meshing fine.

This happened several times . Install dizzy , crank it , doesnt start , 180 opposite from where I installed.

is it a 1:1 ratio or a 2:1 ratio ? I guess thats really my question.

thanks in advance

 

[jimmbo]

HB?
The distributor, will spin at 1/2 the speed of the crankshaft. Most distributors are run from the camshaft as they run at 1/2 engine speed. It is possible to place/time the distributor so it is out by 180 distributor degrees, or 360 engine degrees, which means it will spark between the exhaust and intake strokes, instead of near the end of the compression stroke

When you are looking for TDC, you also need to verify which stroke the engine is on. Both Intake and Exhaust Valves being closed is usually a good indicator that when the piston is also at TDC that it is at the end of the compression stroke and starting the power stroke

 

[Redrig]

HB?
The distributor, will spin at 1/2 the speed of the crankshaft.

Sorry Jimmbo , Harmonic balancer and where my timing marks are.

Okay what you just described there makes total sense now. I was doing it right , just had a misunderstanding of the half speed part.

I thought everything spun equally so when I would bring my harmonic balancer up to TDC , sometimes rotor would be pointing at #1 , other times pointing the exact opposite way and that was messing with my head because I was operating under the impression that they spun equally , I was thinking that something internally was broken.

so basically when looking at only the timing marks when you have the harmonic balancer at TDC , the rotor can be in 2 different places - #1 or exact opposite . I thought it could only be in one place - #1. my bad

thanks for the response and lesson.

 

[jimmbo]

A cylinder in a 4 stroke engine only requires a spark every 720 degrees of engine rotation, once every two revolutions. Some of the engines in the 1990s became distributorless and would fire the plugs every revolution(I guess it was a way to sell more spark plugs)

 

[WIMUSKY]

Yeah, putting the dizzy in at 180° off is a common occurrence if a person isnt careful... You can put your thumb over the plug hole to see if you're on the compression stroke or power/exhaust....