Hi all.

As the subject says, I have a rough idle and an occasional, but constant miss.
I have the following as new:

Distributor - No vacuum advance and is plugged off.
Plugs - RT45s
Leads

Have check the compression and all are smack on 150.
When I pulled the plugs they did look a bit carbon fouled. But car hasn't been out for ages and only turned over once or twice a month.

No vacuum leaks (at least that I can see or hear).
Base timing approx 8BTC
All ports on the carby are plugged off
Vacuum gauge indicates 17-18hg - This does move slightly when it misses and is not perfectly still when idling.

Here is what I think might be an issue:

The EGR valve is not plugged off - could this cause vacuum leak at idle?
I don't have a PCV valve as it has edlebrock valve covers, but each cover does have a breather and white wispy smoke does come out of them both.
All other emission controls are non existent (not an issue here in South Australia).

Think that covers it all, so anyone have any suggestions or where to go back to start covering the basics?

It's non ECM dizzy and carb.

Help much appreciated.

Cheers.

Jonno

 

No hints?

 

have you looked through some vacuum gauge reading charts? might give you an idea or lead to your problem?
https://www.google.com/search?q=vacu...w=1280&bih=699

 

My egr failed last year and had a horrible idle and skip through the low rpm ranges,even plugging it off gave a bad idle situation,new egr and hoses corrected the issue.
1985 305/rochester carb/stock dist and ecm.