• Welcome Visitor! Please take a few seconds and Register for our forum. Even if you don't want to post, you can still 'Like' and react to posts.

I need an opinion on these compressions numbers...


Yeah persistence is key here. I know I have the Duraspark wiring and connections properly configured, I've triple checked and then some. I figure it's either something so painfully obvious that I'm missing it, or it's a stacking errors where multiple smaller items contribute to one big problem.

So goes the world.
 
Mag distributors need to have proper phasing. If you bring the engine up to TDC compression on #1 pull the cap and make sure the rotor is pointed at the #1 lug on the cap and then make sure the start wheel is pointed at the mag pickup.
When the polarity is correct they will both line up. When it is wrong one will line up but the other one won't. Polarity can change phasing by 40 degrees or so. If the rotor is in no mans land between lugs when the mag pickup is lined up with the star wheel you'll get a misfire.
 
Mag distributors need to have proper phasing. If you bring the engine up to TDC compression on #1 pull the cap and make sure the rotor is pointed at the #1 lug on the cap and then make sure the start wheel is pointed at the mag pickup.
When the polarity is correct they will both line up. When it is wrong one will line up but the other one won't. Polarity can change phasing by 40 degrees or so. If the rotor is in no mans land between lugs when the mag pickup is lined up with the star wheel you'll get a misfire.
Now that's not something I'm very familiar with. So far I've only ever had to deal with rotor positions, pickup coils, and that's it.

I'm assuming that is the reluctor wheel, right? It's a bit late for me to check but I've never fooled with it intentionally. Isn't there supposed to be a tooth on the wheel that is to point at pickup coil?
 
Last edited:
Yes, but if you polarity is wrong it wont be when the rotor is pointed at the lug on the cap. I pretty sure it should be the most retarded on old analog system.
The two wires coming off the pickup coil can be swapped.
Remember it will spark when the pickup coil is lined up with the star wheel, regardless of where your rotor is aimed.
Some guys will make a phasing cap. Take an old cap and drill a hole in it next to #1 lug, then you can shoot the timing light and see if the rotor is lined up with the cap when cranking.
 
Last edited:
i assume you are starting with the actual number 1 on cap and tdc on number 1 cylinder and have verified rotation....and actual cylinder order
 

Sponsored Ad


Sponsored Ad

TRS Events

Member & Vendor Upgrades

For a small yearly donation, you can support this forum and receive a 'Supporting Member' banner, or become a 'Supporting Vendor' and promote your products here. Click the banner to find out how.

Recently Featured

Want to see your truck here? Share your photos and details in the forum.

Our Latest Video

TRS Merchandise

Follow TRS On Instagram

TRS Sponsors


Sponsored Ad


Sponsored Ad


Amazon Deals

Sponsored Ad

Back
Top