You might have an advance weight stuck in the full advanced position or one of the weight springs broke allowing quick mechanical advance.

 

So my best bet is to take the dist. out and disassemble and look for any problems ?Are the springs under the points plate?

 

Yup! Just looked at mine to be sure.

 

I know this is off topic but do either one of yall know where i can get a lower shock mount for a 1973 ford f100 custom 2wd? i can't find one anywhere

 

Dual port distributor has front nipple connected to ported vacuum, rear port is retard function and hooks to manifold vacuum(though not usually needed).

 

someone else said it first, but check your timing before you do anything else.

You can check your mechanical advance (weighted springs under the points) by checking your timing while slowly raising the engine RPM. should max out around 3000 rpm IIRC.

Also, since you are still running points, check your dwell.

My guess:

You need to adjust your points dwell and then set your timing. Then you can hook up your vacuum advance and see what is going on there.

being that you have a new vacuum advance, it should be adjustable. check your instructions, but there is usually a set screw under the nipple where the vacuum hose connects at the dist.

my advice in order of operation:
1. check points condition and replace if necessary
2. set point gap and then check dwell timing and correct dwell as needed. if you dont have a dwell meter, get one, otherwise you are just guessing
3. check base timing with timing light and adjust as needed.
4. check mechanical advance, to verify what you are getting. prolly need a manual to know what the total advance should be.
5. check vacuum advance and set it to where the engine runs well.


do all of that and then report back to us how it is running. Remember that setting your timing without checking your dwell is just going to compensate for an improper dwell angle. If your timing is off, it is usually becase your points dwell is off.

6. optional. thow your points away and get a pertronix ignitor 2. You will never regret the upgrade.

 

I'v never had good luck with dual points dist. If you want to keep a points system then get a new single point single advance dist. or change it over to a Pertronix ignitor, it's not that hard to do. JIM

 

He posted dual port, not dual point distributor.

 

Ha ha on me,i guess it's to early in the morning for me,I'l wake later.JIM

 

Thanks guys. I'm planning on switching to pertronics as soon as I can afford to but in the mean time I'll try to round up the equipment to properly check things out. Thanks for all your replies I love this site!

 

Update. Since my dist.was still under warranty, I took it back and swapped it for a single port one and my truck is back to its old self.Thanks to everyone for the help!

 

Great, thanks for reporting back with results.