| Author |
Message |
DAS
Guest
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 Posted:
Sun Jun 05, 2005 10:52 pm Post subject:
Runs great, THEN... |
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I have a 71 911 T... It runs great for about 20-30 minutes, then the tach
jumps around sporadically and it pops and is undrivable. I replace the
plugs, wires, points, coil.... It's like a relay or something fails after
the engine heats up... Any ideas? This must have happened to someone else
at some point. Please help... Thanks.
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Will
Guest
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| Posted:
Sun Jun 05, 2005 11:57 pm Post subject:
Re: Runs great, THEN... |
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"DAS" <dshaff@ptdprolog.net> wrote in message
news:itidnSvQzMNBpj7fUSdV9g@ptd.net...
| Quote: | I have a 71 911 T... It runs great for about 20-30 minutes, then the tach
jumps around sporadically and it pops and is undrivable. I replace the
plugs, wires, points, coil.... It's like a relay or something fails
after
the engine heats up... Any ideas? This must have happened to someone
else
at some point. Please help... Thanks.
|
I know it's hard to believe, esp since you just replaced them, but your
problem still sounds like bad points.
The spring may be weak and/or the points may be burned or improperly gapped.
File them down (emery board for fingernails), and gap them if you want - or
better yet, replace them one more time (with a quality new set and gap them
correctly).
My 72 911T and 76 911S has the same issue at one point or another (no pun
intended)
W |
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DAS
Guest
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| Posted:
Mon Jun 06, 2005 12:13 am Post subject:
Re: Runs great, THEN... |
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Thanks for the reply... Here is more information, do you still think it is
my points...
The last time, I drove the car it left me sit away from home...
Consistently after 20-30 minutes of great running, the car goes crazy...
This time, I left it running while I was washing it... It idles great for
about 25 minutes, then it starting idling really rough, so I got in it and
get on the gas, the tack jumps around like crazy then stays around 0, and it
would pop.... Usually, if I let the car cool down, it will start without
any issue...
What would make the points fail, but then work again? Thanks for the
help...
"Will" <45g4@no-spam.com> wrote in message
news:oWHoe.21460$PR6.9013@tornado.texas.rr.com...
| Quote: |
"DAS" <dshaff@ptdprolog.net> wrote in message
news:itidnSvQzMNBpj7fUSdV9g@ptd.net...
I have a 71 911 T... It runs great for about 20-30 minutes, then the
tach
jumps around sporadically and it pops and is undrivable. I replace the
plugs, wires, points, coil.... It's like a relay or something fails
after
the engine heats up... Any ideas? This must have happened to someone
else
at some point. Please help... Thanks.
I know it's hard to believe, esp since you just replaced them, but your
problem still sounds like bad points.
The spring may be weak and/or the points may be burned or improperly
gapped.
File them down (emery board for fingernails), and gap them if you want -
or
better yet, replace them one more time (with a quality new set and gap
them
correctly).
My 72 911T and 76 911S has the same issue at one point or another (no pun
intended)
W
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william_b_noble
Guest
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| Posted:
Mon Jun 06, 2005 12:13 am Post subject:
Re: Runs great, THEN... |
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does this car have a resistor in series with the coil? if yes, check it or
replace it
"DAS" <dshaff@ptdprolog.net> wrote in message
news:ec2dnb206rlDyD7fUSdV9g@ptd.net...
| Quote: | Thanks for the reply... Here is more information, do you still think it
is my points...
The last time, I drove the car it left me sit away from home...
Consistently after 20-30 minutes of great running, the car goes crazy...
This time, I left it running while I was washing it... It idles great for
about 25 minutes, then it starting idling really rough, so I got in it and
get on the gas, the tack jumps around like crazy then stays around 0, and
it would pop.... Usually, if I let the car cool down, it will start
without any issue...
What would make the points fail, but then work again? Thanks for the
help...
"Will" <45g4@no-spam.com> wrote in message
news:oWHoe.21460$PR6.9013@tornado.texas.rr.com...
"DAS" <dshaff@ptdprolog.net> wrote in message
news:itidnSvQzMNBpj7fUSdV9g@ptd.net...
I have a 71 911 T... It runs great for about 20-30 minutes, then the
tach
jumps around sporadically and it pops and is undrivable. I replace the
plugs, wires, points, coil.... It's like a relay or something fails
after
the engine heats up... Any ideas? This must have happened to someone
else
at some point. Please help... Thanks.
I know it's hard to believe, esp since you just replaced them, but your
problem still sounds like bad points.
The spring may be weak and/or the points may be burned or improperly
gapped.
File them down (emery board for fingernails), and gap them if you want -
or
better yet, replace them one more time (with a quality new set and gap
them
correctly).
My 72 911T and 76 911S has the same issue at one point or another (no pun
intended)
W
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Will
Guest
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| Posted:
Mon Jun 06, 2005 12:13 am Post subject:
Re: Runs great, THEN... |
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What stood out was the jumpy tachometer you mentioned.
I'm not sure a HT (high tension) short due to wet ignition wires or moisture
in the cap would cause the tach problem.
IIRC, a longtime Porsche mechanic whose shop I worked in during summers said
it's usually a symptom of a weak spring mechanism on the points, or burned
points. The weak pring causes the points to "float" on the distributor cam
rather than make solid electrical contact each time. Same outcome if they're
burned.
That is why replacing them and the condenser (<$20, yourself) is better than
filing "old" ones down.
Of course, I could be (and often am) wrong - it was many years ago for me,
but it is a twenty dollar gamble.
Good luck. Post back if you try this and it works.
W
"DAS" <dshaff@ptdprolog.net> wrote in message
news:ec2dnb206rlDyD7fUSdV9g@ptd.net...
| Quote: | Thanks for the reply... Here is more information, do you still think it
is
my points...
The last time, I drove the car it left me sit away from home...
Consistently after 20-30 minutes of great running, the car goes crazy...
This time, I left it running while I was washing it... It idles great for
about 25 minutes, then it starting idling really rough, so I got in it and
get on the gas, the tack jumps around like crazy then stays around 0, and
it
would pop.... Usually, if I let the car cool down, it will start without
any issue...
What would make the points fail, but then work again? Thanks for the
help...
"Will" <45g4@no-spam.com> wrote in message
news:oWHoe.21460$PR6.9013@tornado.texas.rr.com...
"DAS" <dshaff@ptdprolog.net> wrote in message
news:itidnSvQzMNBpj7fUSdV9g@ptd.net...
I have a 71 911 T... It runs great for about 20-30 minutes, then the
tach
jumps around sporadically and it pops and is undrivable. I replace the
plugs, wires, points, coil.... It's like a relay or something fails
after
the engine heats up... Any ideas? This must have happened to someone
else
at some point. Please help... Thanks.
I know it's hard to believe, esp since you just replaced them, but your
problem still sounds like bad points.
The spring may be weak and/or the points may be burned or improperly
gapped.
File them down (emery board for fingernails), and gap them if you want -
or
better yet, replace them one more time (with a quality new set and gap
them
correctly).
My 72 911T and 76 911S has the same issue at one point or another (no
pun
intended)
W
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Ed Beroset
Guest
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| Posted:
Mon Jun 06, 2005 5:19 am Post subject:
Re: Runs great, THEN... |
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DAS wrote:
| Quote: | Thanks for the reply... Here is more information, do you still think it is
my points...
The last time, I drove the car it left me sit away from home...
Consistently after 20-30 minutes of great running, the car goes crazy...
This time, I left it running while I was washing it... It idles great for
about 25 minutes, then it starting idling really rough, so I got in it and
get on the gas, the tack jumps around like crazy then stays around 0, and it
would pop.... Usually, if I let the car cool down, it will start without
any issue...
What would make the points fail, but then work again? Thanks for the
help...
|
Ah, there's a device in there that's designed to do just that -- the
vacuum advance. If the vacuum hoses that lead to the distributor are
cracked and leaking, you'll get all kinds of backfiring and rough
running, including stalling. Check the hoses -- it's a cheap fix.
Does your '71 have a Marelli distributor or the later Bosch type? If
it's a Marelli, I seem to recall that there were particular problems
with it, but I can't remember what -- maybe just replacement parts
availability.
Ed |
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Gary
Guest
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| Posted:
Thu Jun 09, 2005 4:15 pm Post subject:
Re: Runs great, THEN... |
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Don't know if this one has been sitting very long...but my '71 sat for about
8 months with just the
occasional start etc. Then when I was able to drive it again full time, I
experienced the same situation
you're talking about. Driving down the road, coff, coff spit...dead. Let
it set for a few minutes and zoom...we were off again for 20 minutes or so.
Mine turned out to me rust in the fuel tank.....removed it and let an
aviation outfit clean and coat the tank,
while I replaced all the filters and rebuilt the Webbers...TADA...ran like a
champ afterwards.
Hope this helps.
Gary
"DAS" <dshaff@ptdprolog.net> wrote in message
news:itidnSvQzMNBpj7fUSdV9g@ptd.net...
| Quote: | I have a 71 911 T... It runs great for about 20-30 minutes, then the tach
jumps around sporadically and it pops and is undrivable. I replace the
plugs, wires, points, coil.... It's like a relay or something fails after
the engine heats up... Any ideas? This must have happened to someone
else at some point. Please help... Thanks.
|
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DAS
Guest
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| Posted:
Tue Jun 14, 2005 7:43 am Post subject:
Re: Runs great, THEN... |
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I put in another set of points... Started fine, drove it down road and in
about 5 minutes, pop bang boom dead! I engine stalled. I left the key
turned to the one position and popped the hood. I noticed something
interesting. The wine from the fuel pump (sounded like it was coming from
the back side bottom of the engine, near the transmission) was inconsistent.
It would change from high to low... I looked at the fuel filter and noticed
very little fuel in it and it looked like air would push by it as the wine
changed from high to low. Not sure if the fuel pump is strong when started
then dies after a bit of driving... Or maybe I do have a clog that happens
after gas starts sloshing around...
Any ideas or things I can test?
"Gary" <b-and-g@austin.rr.com> wrote in message
news:9VYpe.38104$j51.25967@tornado.texas.rr.com...
| Quote: | Don't know if this one has been sitting very long...but my '71 sat for
about 8 months with just the
occasional start etc. Then when I was able to drive it again full time, I
experienced the same situation
you're talking about. Driving down the road, coff, coff spit...dead. Let
it set for a few minutes and zoom...we were off again for 20 minutes or
so.
Mine turned out to me rust in the fuel tank.....removed it and let an
aviation outfit clean and coat the tank,
while I replaced all the filters and rebuilt the Webbers...TADA...ran like
a champ afterwards.
Hope this helps.
Gary
"DAS" <dshaff@ptdprolog.net> wrote in message
news:itidnSvQzMNBpj7fUSdV9g@ptd.net...
I have a 71 911 T... It runs great for about 20-30 minutes, then the tach
jumps around sporadically and it pops and is undrivable. I replace the
plugs, wires, points, coil.... It's like a relay or something fails
after the engine heats up... Any ideas? This must have happened to
someone else at some point. Please help... Thanks.
|
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| Back to top |
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Gary
Guest
|
| Posted:
Tue Jun 14, 2005 8:13 am Post subject:
Re: Runs great, THEN... |
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|
You'll hate this....hook up a 5 gal gas can and run it to the fuel pump...in
essence bypass the fuel tank.
If you try to drive....I did it in a parking lot. If that works and it gets
past the magic time frame...it is the tank.
Check with your local aviation shops about cleaning it and coating it.
Best of luck,
Gary
"DAS" <dshaff@ptdprolog.net> wrote in message
news:NtKdnUm4ioff2TPfUSdV9g@ptd.net...
| Quote: | I put in another set of points... Started fine, drove it down road and in
about 5 minutes, pop bang boom dead! I engine stalled. I left the key
turned to the one position and popped the hood. I noticed something
interesting. The wine from the fuel pump (sounded like it was coming from
the back side bottom of the engine, near the transmission) was
inconsistent. It would change from high to low... I looked at the fuel
filter and noticed very little fuel in it and it looked like air would push
by it as the wine changed from high to low. Not sure if the fuel pump is
strong when started then dies after a bit of driving... Or maybe I do have
a clog that happens after gas starts sloshing around...
Any ideas or things I can test?
"Gary" <b-and-g@austin.rr.com> wrote in message
news:9VYpe.38104$j51.25967@tornado.texas.rr.com...
Don't know if this one has been sitting very long...but my '71 sat for
about 8 months with just the
occasional start etc. Then when I was able to drive it again full time,
I experienced the same situation
you're talking about. Driving down the road, coff, coff spit...dead.
Let it set for a few minutes and zoom...we were off again for 20 minutes
or so.
Mine turned out to me rust in the fuel tank.....removed it and let an
aviation outfit clean and coat the tank,
while I replaced all the filters and rebuilt the Webbers...TADA...ran
like a champ afterwards.
Hope this helps.
Gary
"DAS" <dshaff@ptdprolog.net> wrote in message
news:itidnSvQzMNBpj7fUSdV9g@ptd.net...
I have a 71 911 T... It runs great for about 20-30 minutes, then the
tach jumps around sporadically and it pops and is undrivable. I replace
the plugs, wires, points, coil.... It's like a relay or something fails
after the engine heats up... Any ideas? This must have happened to
someone else at some point. Please help... Thanks.
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alex
Guest
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| Posted:
Wed Jun 15, 2005 12:15 am Post subject:
Re: Runs great, THEN... |
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is there alot of rust/debry in the fule filter now?
try blowing out the fuel line with compressed air (before the pump towards
the tank)
then drain the tank
if lots of rust comes out then you may want to get it recoated and or check
the fuel lines for rust or kinks
if it looks resonalble run car then blow out the line and drain the tank
untill it looks clean again
in addition i think your model has brass screen inside the tank as well?
"Gary" <b-and-g@austin.rr.com> wrote in message
news:MKsre.40324$j51.29162@tornado.texas.rr.com...
| Quote: | You'll hate this....hook up a 5 gal gas can and run it to the fuel
pump...in essence bypass the fuel tank.
If you try to drive....I did it in a parking lot. If that works and it
gets past the magic time frame...it is the tank.
Check with your local aviation shops about cleaning it and coating it.
Best of luck,
Gary
"DAS" <dshaff@ptdprolog.net> wrote in message
news:NtKdnUm4ioff2TPfUSdV9g@ptd.net...
I put in another set of points... Started fine, drove it down road and in
about 5 minutes, pop bang boom dead! I engine stalled. I left the key
turned to the one position and popped the hood. I noticed something
interesting. The wine from the fuel pump (sounded like it was coming
from the back side bottom of the engine, near the transmission) was
inconsistent. It would change from high to low... I looked at the fuel
filter and noticed very little fuel in it and it looked like air would
push by it as the wine changed from high to low. Not sure if the fuel
pump is strong when started then dies after a bit of driving... Or maybe
I do have a clog that happens after gas starts sloshing around...
Any ideas or things I can test?
"Gary" <b-and-g@austin.rr.com> wrote in message
news:9VYpe.38104$j51.25967@tornado.texas.rr.com...
Don't know if this one has been sitting very long...but my '71 sat for
about 8 months with just the
occasional start etc. Then when I was able to drive it again full time,
I experienced the same situation
you're talking about. Driving down the road, coff, coff spit...dead.
Let it set for a few minutes and zoom...we were off again for 20 minutes
or so.
Mine turned out to me rust in the fuel tank.....removed it and let an
aviation outfit clean and coat the tank,
while I replaced all the filters and rebuilt the Webbers...TADA...ran
like a champ afterwards.
Hope this helps.
Gary
"DAS" <dshaff@ptdprolog.net> wrote in message
news:itidnSvQzMNBpj7fUSdV9g@ptd.net...
I have a 71 911 T... It runs great for about 20-30 minutes, then the
tach jumps around sporadically and it pops and is undrivable. I replace
the plugs, wires, points, coil.... It's like a relay or something
fails after the engine heats up... Any ideas? This must have happened
to someone else at some point. Please help... Thanks.
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DAS
Guest
|
| Posted:
Mon Jun 20, 2005 7:19 am Post subject:
Re: Runs great, THEN... |
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|
I broke down and took the car to my local Porsche guru... They looked at
it and came to the conclusion that the problem was in the tach circuit...
When the car was acting up, they disconnected the tach an it runs fine...
They were going to do more testing to see if they hook up a different tach
if the problem is still gone as they were not sure if the issues was with
the tach or a connection or relay somewhere... Any additional help here
would be appreciated.
"alex" <alexkeysTAKEOUT@hotmail.com> wrote in message
news:ntudnVVIz4_nqjLfRVn-rQ@magma.ca...
| Quote: | is there alot of rust/debry in the fule filter now?
try blowing out the fuel line with compressed air (before the pump towards
the tank)
then drain the tank
if lots of rust comes out then you may want to get it recoated and or
check the fuel lines for rust or kinks
if it looks resonalble run car then blow out the line and drain the tank
untill it looks clean again
in addition i think your model has brass screen inside the tank as well?
"Gary" <b-and-g@austin.rr.com> wrote in message
news:MKsre.40324$j51.29162@tornado.texas.rr.com...
You'll hate this....hook up a 5 gal gas can and run it to the fuel
pump...in essence bypass the fuel tank.
If you try to drive....I did it in a parking lot. If that works and it
gets past the magic time frame...it is the tank.
Check with your local aviation shops about cleaning it and coating it.
Best of luck,
Gary
"DAS" <dshaff@ptdprolog.net> wrote in message
news:NtKdnUm4ioff2TPfUSdV9g@ptd.net...
I put in another set of points... Started fine, drove it down road and in
about 5 minutes, pop bang boom dead! I engine stalled. I left the key
turned to the one position and popped the hood. I noticed something
interesting. The wine from the fuel pump (sounded like it was coming
from the back side bottom of the engine, near the transmission) was
inconsistent. It would change from high to low... I looked at the fuel
filter and noticed very little fuel in it and it looked like air would
push by it as the wine changed from high to low. Not sure if the fuel
pump is strong when started then dies after a bit of driving... Or maybe
I do have a clog that happens after gas starts sloshing around...
Any ideas or things I can test?
"Gary" <b-and-g@austin.rr.com> wrote in message
news:9VYpe.38104$j51.25967@tornado.texas.rr.com...
Don't know if this one has been sitting very long...but my '71 sat for
about 8 months with just the
occasional start etc. Then when I was able to drive it again full
time, I experienced the same situation
you're talking about. Driving down the road, coff, coff spit...dead.
Let it set for a few minutes and zoom...we were off again for 20
minutes or so.
Mine turned out to me rust in the fuel tank.....removed it and let an
aviation outfit clean and coat the tank,
while I replaced all the filters and rebuilt the Webbers...TADA...ran
like a champ afterwards.
Hope this helps.
Gary
"DAS" <dshaff@ptdprolog.net> wrote in message
news:itidnSvQzMNBpj7fUSdV9g@ptd.net...
I have a 71 911 T... It runs great for about 20-30 minutes, then the
tach jumps around sporadically and it pops and is undrivable. I
replace the plugs, wires, points, coil.... It's like a relay or
something fails after the engine heats up... Any ideas? This must
have happened to someone else at some point. Please help... Thanks.
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