258 Distributor question.

[CJ7 Shadow]

The previous owner of my Jeep did the Nutter bypass and Weber carb. I did the rest.

I read somewhere that the computer controlled AMC 258 i6 / 4.2l 's did not have mechanical advance distributors. Is this true? If so, how do I know if mine's been changed?

Thanks in advance for any info y'all can provide.
Shawn

 

[Cj5dave]

The weights are below the rotor, they have the small springs attached at the ends.

 

[gert]

Mine was computer controlled and I thoought it still had the weights in it

 

[CJ7 Shadow]

I guess I could hookup a timing light and disconnect the vacuum advance and see if I get any advance.

Sent from my DROIDX

 

[Cj5dave]

If you have vacuum then its mechanical. Why would electronic need a vacuum hose?

 

[CJim7]

If you have vacuum then its mechanical. Why would electronic need a vacuum hose?

I agree. I havent seen a stock AMC 258 i6 / 4.2l dizzy that didnt have vacuum advance (small vacuum line from carb to dizzy)

 

[CJ7 Shadow]

This is where I got my info from. Paragraph 2B
Upgrade For 258 CID I-6 AMC Jeep Ignition, 1984 To 1990.

 

[CJim7]

I think the only change was in how the computer controlled the vacuum advance....I cant find a mechanical difference in dizzys from 78-90. They may have used different springs, but they are essentially the same.

Distributor, Cap And Rotor, Remanufactured 83506286RK

The only search that came up to support the "junkyard genius'" webpage showed a different dizzy for an 84-90 Grand Wagoneer...everything else showed the CJ4 .2 dizzy as being the same from 1978 to 1990. Pre 1978 was a Prestolight ignition system.

The AMC 258 i6 / 4.2l I used in my CJ was from an '87 YJ and the dizzy was mechanical.