High Revving When the Car is Warm

356 Porsche-related discussions and questions.
Message
Author
Dave Erickson
356 Fan
Posts: 2190
Joined: Sat Oct 26, 2013 9:34 pm
Location: Monterey, CA

Re: High Revving When the Car is Warm

#16 Post by Dave Erickson »

Mike Wilson wrote: Tue Aug 02, 2022 7:22 pm It looks like it could definitely use a good cleaning.

Mike
+1.

Suggest you remove and disassemble the distributor and clean it thoroughly in an ultrasonic. Then oil and reassemble, replace any broken parts.

Kim Reeves
356 Fan
Posts: 32
Joined: Fri Jul 01, 2011 10:28 am

Re: High Revving When the Car is Warm

#17 Post by Kim Reeves »

Morning all! So i sprayed it with WD40 and left it over night and it will not budge. It's not something i want to use pliers to tug on - any other recommendations? feel like i am close to solving this and really appreciate the advice!
Shelter Island, NY
1964 356SC Coupe

User avatar
Mike Wilson
Classifieds Monitor
Posts: 11492
Joined: Tue Apr 15, 2008 4:37 pm
Location: SW Los Angeles

Re: High Revving When the Car is Warm

#18 Post by Mike Wilson »

WD-40 is not a penetrant. WD stand for Water Displacement. Use a product like Kroil, Liquid Wrench, etc.to free it up.

Mike
Mike Wilson
Lomita, CA
'63 B coupe

User avatar
Doug McDonnell
356 Fan
Posts: 6061
Joined: Sat Apr 05, 2008 8:21 am
Location: Augusta,Michigan

Re: High Revving When the Car is Warm

#19 Post by Doug McDonnell »

When I am in deep and having a problem with 50-60 year old parts that I have no experience rebuilding I send the part to an expert. I cured the same problem by having Bruce (CFI) rebuild my distributor. There are several Vendors who rebuild distributors and have the correct machines to do so. Not all of us can or should do everything on our old precious cars.
1965 356C 2000 BMW 740i Sport 1967 Honda CL77 There is never enough time to do it right, but always enough time to do it over.

User avatar
Mike Wilson
Classifieds Monitor
Posts: 11492
Joined: Tue Apr 15, 2008 4:37 pm
Location: SW Los Angeles

Re: High Revving When the Car is Warm

#20 Post by Mike Wilson »

Very good point, Doug. Having the distributor professionally rebuilt removes all variables of possible malfunctions.

Mike
Mike Wilson
Lomita, CA
'63 B coupe

Kim Reeves
356 Fan
Posts: 32
Joined: Fri Jul 01, 2011 10:28 am

Re: High Revving When the Car is Warm

#21 Post by Kim Reeves »

Let me go and get some liquid wrench - if it doesn't come off. I will take the whole thing off and send out for rebuild! Good advice. I hate forcing some things and she is precious!
Shelter Island, NY
1964 356SC Coupe

User avatar
Wes Bender
356 Fan
Posts: 4861
Joined: Wed Aug 27, 2008 10:54 am
Location: Somewhere in the Gadsden Purchase, USA

Re: High Revving When the Car is Warm

#22 Post by Wes Bender »

Kim, it would help if you put your approximate location in your information that displays to the right of your posts. That we we can better suggest someone to rebuild your distributor (or other things, for that matter). For example, if you are near the east coast, Bruce Smith can do your distributor. Out here in the west, we tend to recommend John Jenkins, reachable through 356 Carb Rescue.

This same advice would apply to others as well. Show us a rough location, please!
Some days it's just not worth chewing through the restraints.....

User avatar
Mike Wilson
Classifieds Monitor
Posts: 11492
Joined: Tue Apr 15, 2008 4:37 pm
Location: SW Los Angeles

Re: High Revving When the Car is Warm

#23 Post by Mike Wilson »

+1, Wes.

Mike
Mike Wilson
Lomita, CA
'63 B coupe

Dave Erickson
356 Fan
Posts: 2190
Joined: Sat Oct 26, 2013 9:34 pm
Location: Monterey, CA

Re: High Revving When the Car is Warm

#24 Post by Dave Erickson »

Kim, don't pull on the top, rotate it... saturate the felt with oil and work the top back and forth, using an old distributor rotor. Don't be afraid to use some force, the rotor is plastic so you can't hurt the top.

User avatar
Harlan Halsey
356 Fan
Posts: 2340
Joined: Fri Mar 02, 2012 2:05 pm
Location: No Cal SF Peninsula

Re: High Revving When the Car is Warm

#25 Post by Harlan Halsey »

My 356s all exhibit something of the higher idle hot than cold situation. Therefore, I adjust the idle hot and just keep the engine idling with the hand throttle or the accelerator when cold. No biggie.

Pulling the distributer and replacing it is trivial if you do it at #1 TDC. Then take it to a Sun Distributer Tester, hopefully after cleaning, and get the full low down. What is the advance curve and is it repeatable? Are all four cylinders firing 90 -/+1 deg apart? Where does full advance start and is it constant all the way to 6,000 RPM? Where does idle advance start?

If the distributer isn't functioning perfectly, send it out for repair, and get it back with those questions answered. The distributer is a small system, there is no reason not to have it functioning perfectly so you can spend your resources on something else.

Kim Reeves
356 Fan
Posts: 32
Joined: Fri Jul 01, 2011 10:28 am

Re: High Revving When the Car is Warm

#26 Post by Kim Reeves »

Quick update - i took out the distributor and cleaned it thoroughly and oiled her up. Redid the static timing - turns out the SC is 3.6mm not 5. I have a strobe coming in and will test the higher revs. She runs a little better since the cleaning though! Come winter, i will send the distributor out for full rebuild, as you said, it would be good eliminate it from the issue.
Shelter Island, NY
1964 356SC Coupe

Kim Reeves
356 Fan
Posts: 32
Joined: Fri Jul 01, 2011 10:28 am

Re: High Revving When the Car is Warm

#27 Post by Kim Reeves »

Another quick update - once the strobe came in i was able to set the advance timing at 30 degrees from the 3.6mm SC static timing mark. The idle was high - reduced evenly on both sides and the the timing is right on the markings. BUT the revs at 3000 RPM on the advanced timing, does wobble back and forth. So perhaps the advanced mechanism on the distributor needs to be redone and as i mentioned before, she will be sent out this winter. Either way, she runs MUCH better and doesn't sound like i am taking off when i idle.
Thank you all!
Shelter Island, NY
1964 356SC Coupe

User avatar
John Brooks
356 Fan
Posts: 2146
Joined: Tue Jul 08, 2008 11:50 am
Location: Whidbey Island WA.
Contact:

Re: High Revving When the Car is Warm

#28 Post by John Brooks »

Kim

Try static timing without the engine running first. Then drive it until it warms up, when the idle rpm goes up, then put the strobe on it see where the advance has gone to at idle. Then retard the idle timing back to static point when hot. See if the RPM backs down, if so, then check it at 3k and note the max advance. Let it cool down, then check with the strobe at cold idle again. Note where it is. See how much the timing retarded to get it back to 6-800 rpm idle.

This will give you a base line to compare to when you rebuild it. You may find a slight retarded static timing may calm down the idle to drive it. It will start and you may have to pedal the cold idle for a minute but it may get you back to drivable.
John Brooks

62 Roadster
66 912
84 Cab
getting pushed around in porsches since 1965

Pete Indelicato
356 Fan
Posts: 408
Joined: Mon Apr 13, 2020 2:42 pm
Tag: 356 owner
Location: Yountville, CA

Re: High Revving When the Car is Warm

#29 Post by Pete Indelicato »

What type of carbs, are adjusting screws at stop when there is a fast idle--carb linkage hung up somewhere? way to rich mixture?
1963 T6 couple #212891, motor #*KD*P*730464

User avatar
Brian R Adams
356 Fan
Posts: 3292
Joined: Thu Mar 27, 2008 1:34 pm
Location: N. Nevada

Re: High Revving When the Car is Warm

#30 Post by Brian R Adams »

Re: lubing the distributor, my favorite aftermarket manual is the Autobooks (written by Kenneth Ball, a Briton). But it does feature this oddity in the Ignition chapter. No mention at all of the felt inside the top of the cam, but rather a gap in the breaker plate and "injecting" oil drops:
Ball_2.jpg
Ball_1.jpg
-
Welcome to the era of policy-based evidence-making.

Difficile est saturam non scribere (Juvenal)

Post Reply