HEI distributor tuning problem

[formikaus]

Sorry to hear all the problems you are having. When i put my Accel billiet HEI with a supercoil cap in, I did not use the vacuum advance. I just left it capped off out of the box. I did still have some pinging at the same speed range ONCE THEY STARTED ADDING ETHANOL!!!!! I started putting in 93 and it quit. With it capped off I did still get around 18 mpg's, but I am running a stock cam, 700R4, and 308 gears. Like I have said before, I feel for you. A engine noise is as bad as door glass without weatherstripping....it will drive you crazy! Lol.

[WadmalawJoe]

[quote=LONGHAIR;5950317]How much vacuum does your engine make? At idle? At the pinging point?
It seems like there is still too much vacuum advance at that rpm.

I have a vacuum pump, but not a vacuum gauge.... its on the list...
I might could use the gauge on the vacuum pump somehow, I will look into that.

Originally Posted by formikaus

Sorry to hear all the problems you are having. When i put my Accel billiet HEI with a supercoil cap in, I did not use the vacuum advance. I just left it capped off out of the box. I did still have some pinging at the same speed range ONCE THEY STARTED ADDING ETHANOL!!!!! I started putting in 93 and it quit. With it capped off I did still get around 18 mpg's, but I am running a stock cam, 700R4, and 308 gears. Like I have said before, I feel for you. A engine noise is as bad as door glass without weatherstripping....it will drive you crazy! Lol.

18 mpg!!!! nice, this isn't downhill is it? ...lol


Nobody in town has a adjustable vacuum can with a limiter plate, so I would either have to order one or take it out of the mechanical advance.
I read some about making one, I have three vacuum cans to use, so I might try that.

Thank you everyone and I will update with more info asap.

[WadmalawJoe]

I ordered a limiter plate from Summit. They actually sell the little piece by itself for $3. Cost more to ship it...lol They also carry it in their stores.
I think it will get here in the next couple of days.

[WadmalawJoe]

Alright, I got the limiter plate and installed it. I immediately went to the half way notch hoping to cut the advance in half after all the hassle its been giving me. Well, it didn't, I still had a full 20 degree advance and for some reason it was all in as soon as I plugged in the advance! I ended up switching to the heaviest springs and all the way to the last notch. That cut the advance by 6 degrees.
Right now I have the initial timing at +8 , then centrifugal/mechanical is +20, the advance at +14 totaling 43. The tapping/predetonation is gone and she runs fairly smooth. I want to do some more fine tuning because I think it can tweak it up a little. I'm waiting on some nicer weather, its been ugly lately.
I will post again when I get it fine tuned some more.

[Longhorn 70]

Originally Posted by WadmalawJoe

...
Right now I have the initial timing at +8 , then centrifugal/mechanical is +20, the advance at +14 totaling 43. The tapping/predetonation is gone and she runs fairly smooth. I want to do some more fine tuning because I think it can tweak it up a little. I'm waiting on some nicer weather, its been ugly lately.
I will post again when I get it fine tuned some more.

Good going Joe. We are proud of you for getting this far. Let us know how the tuning goes.

[magwakeenercew2jh]

62 posts and a "Job well done".

What a great Forum.
Made up of a great group of folks.

[WadmalawJoe]

Well, the job is not done.....
The noise came back after a couple days. It was warmer last weekend when I set everything. Then it turned colder for the week. I drove the truck everyday last week. So I'm thinking maybe the carb (edelbrock a pos imho) has something to do with it. It has a manual choke so I'm controlling the choke, but the thing never consistently idles the same. So I'm thinking the vacuum probably changes to. I don't know.... I will be adding a vacuum gauge soon though.
Another tidbit of info; I noticed the limiter plate would only limit the advance by 6 degrees at the maximum setting. The advance can was a Mr. Gasket brand that I picked up a couple weeks ago. Yesterday, I took that off and put the other one back on (the one that came with the distributor) I had swapped them around thinking it was a can issue. Right away I noticed the arm coming from the can is slightly different in length. If I wanted to max the limiting plate I would have to jam the arm all the way, which would probably mean zero advance. I set it at the halfway notch and closed the distributor up and checked it out. Timing was at +10 initially, plugged the dist. in and it went to +20, so apparently the halfway notch cuts the advance by 10.
I adjusted the initial timing to +15 and took it for a drive. Well the tapping started at 2,300 rpms and was present through 2,600 rpms. My wife rode with me and says I'm overly paranoid as the tapping isn't very loud. That statement worries me some, because at some point I might hear, the car was only making a little noise before it died....lol
Anyway, I feel like I'm back to square one. At least, I have gained some knowledge about distributors and such, thanks to everyone on here. I will keep picking at it and see what I come up with.
Maybe I should have titled this Joe's HEI and tapping blog....