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Posted by: tdgray Jul 3 2006, 08:15 AM

So I'm trying to get the car running better and solve my low idle problem etc. So I am doing a tune-up.

I got a good dwell combo meter and hooked her up. Dwell read 48 on intial start up. Rev it up no problem.

Ran it for awhile just fussing with things and looking for possbile air leaks (new vac hoses, no leaks).

Look at the dwell... no probs 48 at idle. Rev it up to 3,500 to attempt timing check. Needle moves down about 5 degrees. Try it again same thing. Try it again moves down 6 degrees.

At this point I stop.

Is my dist shitted ?

I found a rebuilt model from parts america for $46.00. Should I just go ahead and replace it and the trigger points anyway?

Posted by: newto914s Jul 3 2006, 08:41 AM

Did you remember to plug the vacuum advance? It will change the dwell on you as it pulls vacuum, I'm pritty sure.

Posted by: Gint Jul 3 2006, 08:50 AM

You have to remove and plug the vacuum advance hose (and retard if you have it) when testing dwell.

Provided all else is correct, that's typically a sign that your dizzy shaft has too much wobble (needs a rebuild). The last time I had that issue, the base plates were moving too much. Eventually I came to find that the little folded over tang that holds the two plates together wasn't folded over enough and was allowing the top plate to move up, thereby changing the dwell. Took me a little while to find it...

Posted by: tdgray Jul 3 2006, 09:13 AM

Yep hose pulled and plugged.

I'm thinking this may be part of my idle problem.

Any thoughts

Posted by: Cap'n Krusty Jul 3 2006, 09:53 AM

$46 bucks? The parts cost far more than that, wholesale. You need a breaker plate, which is available, but not specifically as a 914 part. The plate comes with new points, and you might as well replace the condenser. Occasionally the shaft bushings are worn out, but it's not usually a problem. The vacuum can might also be bad, but that's a separate issue. A good breaker plate won't show a dwell chance as the vacuum moves it. The Cap'n

Posted by: tdgray Jul 3 2006, 09:57 AM

I dunno... just looked it up on PA website.

This what I came up with.

Wrong thing Cap'n


http://www.partsamerica.com/ProductDetail.aspx?mfrcode=A1C&mfrpartnumber=31915&parttype=218&ptset=A

Posted by: Cap'n Krusty Jul 3 2006, 10:21 AM

"Cardone"? Ask me about the FIVE calipers to get none. Brad kindly gave me a used pair because Cardone couldn't sell me one that didn't leak. Partsamerica is a generic parts house, selling cheap crap at low prices. They push Fram filters because they get big advertising copays to do so, and Monroe shocks, which are crap on Porsches and everything else other than detroit iron. The list goes on. If you care about your car, buy from 914 friendly suppliers who care about your car, your business, and YOU.

The Cap'n

Posted by: Aaron Cox Jul 3 2006, 10:23 AM

get a pertonix

Posted by: anthony Jul 3 2006, 10:39 AM

Pertronix and cleaning/lubing my distributor smoothed out my idle and jumpy timing mark.

Posted by: newto914s Jul 3 2006, 12:15 PM

I don't know, for $46 you can afford to try it out. I'd buy it, install it, and drive the car around while rebuilding the one you have. Then put the old one back in and return the PA one, or keep it as a back up. Then you won't have any down time with your car, and will get to see if the cheap-o rebuilds are really that bad.
I'm with the Cap in supporting our vendors, but the Autozone alternator($50) and volt regulator($6) I installed 18months back seem to be doing OK so far(I was in a bind and need the parts ASAP)

Posted by: Dr. Roger Jul 3 2006, 12:49 PM

when dwell angle decreases at higher RPM's that means that there is less time that the coil is being saturated. Or put another way, the points are staying open longer at higher RPM's.

sounds to me like the points return spring is weak.

or what the cap'n said, that the plate is not allowing accurate advance movement around the dizzy shaft. (if the centrifical advance plate can rotate, but does so at varying distances away from the cam lobes, you will get varying dwell.

i'd start with points spring. just bend it so that, when reinstalled, it has more pressure on the points. then give it a little conservative dab of moly grease or comparable on the cam area.. (warning: the points lobe/contact area is plasitc and cannot take too much spring pressure or you will experience premature wear of points.) (read "Pertronix conversion") =-)

your pal,
roger

Posted by: r_towle Jul 3 2006, 01:28 PM

same problem.
resolved with 0.05 cents of grease, and time.

remove , clean, regrease, and replace the breaker advance plates.
the 30 year old grease gets wierd, and sticky...

Rich

Posted by: tdgray Jul 3 2006, 05:30 PM

Points are brand new.

I understand what the Cap'n is saying... but most of what we buy anymore is shit. It is all rebuilt in China, Tawian or wherever shit.

With this in mind though. Samson has a point. For 46 bucks who knows

I'm going to check the plates etc.

I am going to check a few more things out before I make the leap.

I hate changing distributors.. even if they are as esay as the 914 ones.

Oh and BTW... I definitley want to go Pertronics... I have one on my MGA and love it. Got to get this sorted out first.