Dead cylinder help
- Jonathan Halpern
- 356 Fan
- Posts: 135
- Joined: Sun Jul 18, 2010 10:38 am
- Tag: 1964 356C built 7/16/63 1987 911 Carrera
- Location: Southern California
Re: Dead cylinder help
i simply attached the spark plug from cylinder #3 into wire #3 and allowed it to spark to the chassis/ground to confirm ignition. I had a new spark plug in the engine to keep compression. I also tried the new plug since it was already installed, still a dead cylinder. I pulled the new plug and it was wet with gas.
In further testing, I also realized that cylinder #1 is weak compared to #2 and #4 as tested by pulling spark plug wires from the cap one by one and listening to idle drop.
Jonathan
In further testing, I also realized that cylinder #1 is weak compared to #2 and #4 as tested by pulling spark plug wires from the cap one by one and listening to idle drop.
Jonathan
- Harlan Halsey
- 356 Fan
- Posts: 2340
- Joined: Fri Mar 02, 2012 2:05 pm
- Location: No Cal SF Peninsula
Re: Dead cylinder help
I recall a case recently which puzzled us for quite a while. It turned out that the resistors in the plug ends had begun to fail. Disassembling the plug ends and replacing the resistors with solid conductors was the answer. Probably interferes with radio reception, but the now car runs well.
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- 356 Fan
- Posts: 1347
- Joined: Fri Dec 12, 2008 1:15 pm
- Location: coos bay oregon
- Wes Bender
- 356 Fan
- Posts: 4861
- Joined: Wed Aug 27, 2008 10:54 am
- Location: Somewhere in the Gadsden Purchase, USA
Re: Dead cylinder help
.. or a leak-down test. One or the other might show something.
Some days it's just not worth chewing through the restraints.....
- Jonathan Halpern
- 356 Fan
- Posts: 135
- Joined: Sun Jul 18, 2010 10:38 am
- Tag: 1964 356C built 7/16/63 1987 911 Carrera
- Location: Southern California
Re: Dead cylinder help
I can do both, leakdown and compression test. Maybe first is yanking the valve cover and seeing what I can see and checking gaps. All the head work and other work was done by a friend and a very good 356 mechanic. Anything is possible, of course.
Jonathan
Jonathan
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- 356 Fan
- Posts: 446
- Joined: Fri Dec 03, 2010 7:42 am
Re: Dead cylinder help
my vote is for "clogged idle jet"
- Jonathan Halpern
- 356 Fan
- Posts: 135
- Joined: Sun Jul 18, 2010 10:38 am
- Tag: 1964 356C built 7/16/63 1987 911 Carrera
- Location: Southern California
Re: Dead cylinder help
Would a clogged idle jet cause a rich condition? I cleaned them and cleaned them again. Easy to try again or swap with another I have on hand.
Jonathan
Jonathan
- Martin Benade
- 356 Fan
- Posts: 12195
- Joined: Wed Nov 23, 2011 10:52 am
- Location: Cleveland, Ohio
Re: Dead cylinder help
That would not make it rich, and would likely leave that plug bone dry.
Cleveland Ohio
62 Cabriolet
56 VW
02 IS 300
04 Sienna
62 Cabriolet
56 VW
02 IS 300
04 Sienna
- Jonathan Halpern
- 356 Fan
- Posts: 135
- Joined: Sun Jul 18, 2010 10:38 am
- Tag: 1964 356C built 7/16/63 1987 911 Carrera
- Location: Southern California
Re: Dead cylinder help
Thats what I assumed. Hopefully will get to the garage later today or tomorrow to continue testing/checking.
Jonathan
Jonathan
- Paul Hemburrow
- 356 Fan
- Posts: 32
- Joined: Sun Feb 09, 2020 4:00 pm
- Location: Western Australia
- Instagram: @salt_and_pepper_adventures
Re: Dead cylinder help
What did you eventually find that resolved the issue?
Paul
Perth, Western Australia
Perth, Western Australia
- Jonathan Halpern
- 356 Fan
- Posts: 135
- Joined: Sun Jul 18, 2010 10:38 am
- Tag: 1964 356C built 7/16/63 1987 911 Carrera
- Location: Southern California
Re: Dead cylinder help
Hi Paul,
I’m embarrassed to say I haven’t gotten around to it. Been busy with other cars and projects and the 356 is dormant. I’ll post an update as soon as I get it resolved.
Jonathan
I’m embarrassed to say I haven’t gotten around to it. Been busy with other cars and projects and the 356 is dormant. I’ll post an update as soon as I get it resolved.
Jonathan
- Paul Hemburrow
- 356 Fan
- Posts: 32
- Joined: Sun Feb 09, 2020 4:00 pm
- Location: Western Australia
- Instagram: @salt_and_pepper_adventures
Re: Dead cylinder help
I had the issue after a carby rebuild but had cylinders 3 and 4. It turned out to be a blocked idle circuit!
Paul
Perth, Western Australia
Perth, Western Australia
- Joris Koning
- 356 Fan
- Posts: 2505
- Joined: Thu Mar 27, 2008 12:38 pm
- Location: Netherlands
Re: Dead cylinder help
Had this exact thing happen to me yesterday while setting the carbs on my S90. Measured the resistance and it was something like 50M ohm. Luckily I had one original Beru connector in my stash. Runs like a peach now.Harlan Halsey wrote: ↑Mon Sep 30, 2019 3:12 am I recall a case recently which puzzled us for quite a while. It turned out that the resistors in the plug ends had begun to fail. Disassembling the plug ends and replacing the resistors with solid conductors was the answer. Probably interferes with radio reception, but the now car runs well.
'56 Coupe
'57 Coupe
'59 Cab
'60 Coupe
'57 Coupe
'59 Cab
'60 Coupe
- Jonathan Halpern
- 356 Fan
- Posts: 135
- Joined: Sun Jul 18, 2010 10:38 am
- Tag: 1964 356C built 7/16/63 1987 911 Carrera
- Location: Southern California
Re: Dead cylinder help
Blocked idle circuit is still my top thought. I’m just concerned with the wet plug on mine.
Jonathan
Jonathan
- Jon Schmid
- 356 Fan
- Posts: 1797
- Joined: Thu Jun 26, 2008 4:32 pm
- Location: La Mirada, CA
Re: Dead cylinder help
David Jones' suggestion gets my vote as to your next move. Either eliminate carburetion or ignition as the root cause. I'd be damned if it ended up being a combination of the two.
"Jonathan, you could swap carbs side to side and do not worry about the linkage, just see if it will run at idle and if the problem transfers."
Good luck and enjoy Arrowhead!!
"Jonathan, you could swap carbs side to side and do not worry about the linkage, just see if it will run at idle and if the problem transfers."
Good luck and enjoy Arrowhead!!