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Join Date: Oct 2008
Posts: 172
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jolty running engine when it gets hot
HI, i have a porsche 911s 1975, when i take the car out it runs well to start with ,but after about 30 miles when the engine gets hot it can judder when im only pressing the accelerator lightly, if i then press the accelerator down a bit more the engine will go through the judder , also when i pull away i can get this judder , the engine seems to run well when colder , has anybody else got the same sort of thing ,and can anybody tell me the problem , thanks
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02-04-2010, 09:28 AM
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Registered
Join Date: Oct 2006
Location: MYR S.C.
Posts: 17,321
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as a basic starting point, have you changed the cap and rotor and plugs? after that, you start to get into more involved stuff. do this and then we can go from there.
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86 930 94kmiles [_  _] RUNNING:[__] NOT RUNNING: ____77 911S widebody: SOLD88 BMW 325is 200K+ SOLD 03 BMW 330CI 220K:: [_ _] RUNNING: [__] NOT RUNNING:01 suburban 330K:: [_ _] RUNNING: [__] NOT RUNNING:RACE CAR:: sold |
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02-04-2010, 10:11 AM
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Join Date: Jul 2009
Location: Bedford NH
Posts: 122
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Same thing happened to me with my '74. In my case it was corrosion that had built up on the spark plug wire terminations in the distributor cap. Cleaning this, replacing the rotor and distributor cap seemed to have solved my problem.
My car sits for long stretches over the winter. Where I am, it is not unusual to see a 40 degree change in temperature in just 24 hours. When this happens, I get a lot of condensation build up in the car which starts to effect a lot of things - notably wiring. Hope this helps. Tony
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Tony V 90 911 C4 Coupe 74 911S Targa - (Gretchen) - sold |
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02-04-2010, 10:12 AM
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Registered
Join Date: Jul 2001
Location: Portland Oregon
Posts: 7,007
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Hi,
Sounds like its time to check the CIS fuel injections's control pressures as well as see if the injectors are spraying properly. You may have a warm-up regulator issueand/or need injector cleaning (this is done by a Bosch Service Center).
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Steve Weiner Rennsport Systems Portland Oregon (503) 244-0990 porsche@rennsportsystems.com www.rennsportsystems.com |
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02-04-2010, 10:28 AM
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Join Date: Oct 2005
Location: Capistrano Beach, Ca.
Posts: 7,235
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Ordinarily I would say do the easiest test first--check fuel presures--but in this case I would almost bet it is an ignition issue, as mentioned by others. How old are the ignition components, including the spark plug wires and connectors? These are classic symptoms of an ignition fault where heat causes increased resistance. Old Beru connectors, which are stock, have a tendancy to develop faults which often only appear after warm up. Get all ignition components it top shape before progressing further.
I suspect you don't have fuel gauges to test the pressures, so cleaning up the ignition should be the first step, IMO.
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L.J. Recovering Porsche-holic Gave up trying to stay clean Stabilized on a Pelican I.V. drip |
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02-04-2010, 10:43 AM
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Join Date: Oct 2006
Location: MYR S.C.
Posts: 17,321
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ignition.
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86 930 94kmiles [_ _] RUNNING:[__] NOT RUNNING: ____77 911S widebody: SOLD88 BMW 325is 200K+ SOLD 03 BMW 330CI 220K:: [_ _] RUNNING: [__] NOT RUNNING:01 suburban 330K:: [_ _] RUNNING: [__] NOT RUNNING:RACE CAR:: sold |
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02-05-2010, 06:24 AM
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