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Early 911 Question - When points go bad
Can someone with some experience with points in the early cars tell me what symptoms a bad set of points displays? I checked the gap and cleaned the contacts (a little black) but I don't have a dwell meter. Any info would be appreciated.
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David 1972 911T/S MFI Survivor |
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Do you still have the CDI ignition in your car? If so, the tach typically starts to act irradically when the points need attention.
However, with the CDI, the points are only a signal to trigger the CDI. Getting the gap and dwell correct is not that critical. Setting them close is good enough.
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Rex 1975 911s and 2012 Range Rover Sport HSE 1995 BMW R1100RS, 1948 Harley FL |
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Poor performance and missing are usual sxs. As the point gap and hence dwell angle changes so does the timing. The rubbing block tends to wear closing the gap. Points can arc forming little blobs of metal and even bridge the gap. When this happens to coil doesn't get a clean signal. If you have significant arcing you should replace the condensor. This site is for Yamaha motorcycles but the principles are the same.
IGNITION BREAKER POINTS MAINTENANCE |
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What problem are you having?
With my car, at every oil change I burnish the points with an ignition file, wipe the inside of the cap and verify that each spark plug wire is properly seated.
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Harry 1970 VW Sunroof Bus - "The Magic Bus" 1971 Jaguar XKE 2+2 V12 Coupe - {insert name here} 1973.5 911T Targa - "Smokey" 2020 MB E350 4Matic |
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I got tired of points and put a Pertronix Hall effect module in my distributor. I don't think about points any more. Best $100 i have ever spent.
Dwell meter is a great idea. Dwell does have an effect on you timing.
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RGruppe #79 '73 Carrera RS spec 2.7 MFI 00 Saab 95 Aero wagon stick 01 Saab 95 Aero wagon auto 03 Boxster 90 Chevy PU Prerunner....1990 |
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Pertronix!!!
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Banned but not out, yet..
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I will say it one more time for emphasis Pertronix! Get it and forget it.
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An air cooled refrigerator. ‘Mein Teil’ |
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Pertronix! But keep your Points in the glove box just in case the Pertronix fails.
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Thank you everyone.
The problem I am having is lack of performance, a little bucking while accelerating, and a sense that the timing is off. The car becomes harder to drive smoothly and seems to run a little hotter. The last time this occurred a mechanic burnished the contacts and reset the gap, so I suspect the points are going bad again. I considered the pertronix but I don't have the experience to remove the entire distributor and get it back correctly. Plus, since the car is completely stock (to the eye) I wasn't sure I wanted to add an extra wire to the fuse block. I have changed points, but it has been 25+ years. I think I'll give it a shot and see what happens.
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David 1972 911T/S MFI Survivor |
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Changing points is not a big deal. Just make sure you have a dwell meter and a good timing light.
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1973 911S (since new) RS MFI specs 1991 C2 Turbo |
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improperly gapped points usually show as a bouncing tach and erratic idle, and, as pointed out, if they are to the point where the are almost closed, the symptoms become very similiar to what you are describing.
if it's been 25 years, be careful with the set screw when you get it out, if you drop it, it's going to go where the sun don't shine, and you better have a replacement handy - you'll see what I mean when you get in there. when's the last time you inspected the mesh filter inside the gas tank? - just pull out the gauge sending unit and shine a flashlight in there. Bill K
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73 911T MFI, 76 912E, 77 Turbo Carrera Last edited by bkreigsr; 01-24-2011 at 09:12 AM.. |
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OMG - what a difference. I installed the new points I got from our host, gapped them at 014 and all the problems disappeared. No backfiring, no stumbling, runs cool and strong.
Upon close examination of the old points, I noticed not pitting, but the plastic/bakealite "cam follower" was very worn. With strong reading glasses on I could not see them open - but I suppose they must have since it did run. Also, my very erratic tach problem went away. Glory be.
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David 1972 911T/S MFI Survivor |
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Follow up questions:
- Anyone know the expected life time of a good set of points? - I had to remove the flapper mechanism on the air cleaner to get to the screw that holds the points. Is it possible to do the job without removing this mechanism? - Is there anything wrong with just leaving that mechanism off?
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David 1972 911T/S MFI Survivor |
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David, I replace the points every 10-15k or every three years (garage queen). I would order the Bosch Distributor grease from our host and apply that to the shaft where the "cam follower" is hitting. You should get a dwell meter off of e bay and take the guess work out of the point gap. I am assuming that you are checking the timing to make sure it is correct. If not, get Wayne's book and a timing light from a local automotive parts store or e bay. Good luck. Steve
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Steve 1970 911T SOLD 1989 3.2 Carrera 2013 991 Carrera S |
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+1 pm the Bosch dizzy grease. Don't use any other grease. Without a SMALL dap of dizzy grease the point block will wear very fast causing your gap to decrease.
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Is there something special about distributor grease? I used the smallest amount of white (lithium?) brake grease but I can redo it if necessary.
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David 1972 911T/S MFI Survivor |
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Quote:
Distributor grease is specifically designed to resist this attack. A tube of the stuff will last lifetime.
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Harry 1970 VW Sunroof Bus - "The Magic Bus" 1971 Jaguar XKE 2+2 V12 Coupe - {insert name here} 1973.5 911T Targa - "Smokey" 2020 MB E350 4Matic |
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points need to "break in"
if no grease applied it could be a few hundred miles if greased it could be a 1,000 miles if me i'd check timing every couple of hundred to know what's happening with point gap. When all is steady then every 5k miles this is only my routine with points and Bosch points is quality imo
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Besides Pertronix, Crane Cams as well as other manufacturers offer a breakerless replacement for the Bosch distributor.
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If you have the skill to successfully replace the points you can install a Pertronix. Same level of (non-) difficulty. That being said, maintaining the points works just as well.
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Howard '76 911S '53 Nash (!) '01 Audi TT '82 GPZ-550 |
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