Road Trip Hesitation/missing Issues

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Andrew J Moser
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Road Trip Hesitation/missing Issues

#1 Post by Andrew J Moser »

New member to this forum, still doing some searching but figured I'd post trying to help my dad. I'm more of a mid 80's BMW guy at the moment so forgive me if I get some terminology wrong

I'm driving with my dad from St. Louis to Naples Fla in his 59' 356 cab. He's owned this for over 25yrs, it's a garage queen, if he puts 100 miles a year on it I'd be surprised. He bought it fully restored from and has had it serviced solely by Reid Vann in St. Louis whenever the slightest thing is wrong with it . It's an extremely well taken care of car, aside from lack of driving it more IMO. Anyway, we planned this trip for like 6 months, all back roads, no interstate the whole way, so he brought it in for service to have them go over everything that might need to be fixed or replaced. New Fuel tank and lines a year ago, new clutch as well. They replaced the points, coil, condenser, fuel filter, plugs, adjusted the carbs last week. Drove it several times before we left for 10-15 miles each duration, pretty hard, it ran perfect.

Anyway, we left town yesterday, made it about 10 miles before I noticed the Idle would not back down when we came to a stop consistently. It would hang around 2k, then after some time, drop to normal. Sometimes it would, sometimes it wouldn't. We kept going figured we'd keep an eye on it, about an hour and a half later, it started hesitating above 3K. You'd get on it, and it felt to me at least, like it was a fuel issue, like it wasn't getting enough fuel. This was mainly in 1st thru 3rd, seemed more under load, if I baby'd it, it was less noticeable, but if we were going up a hill or under heavy acceleration it was obvious. We stopped and called the shop, he suggested the idle issue could be a bad spring in the distributor or one of the magnets is stuck and but were at a loss for the hesitation diagnosis, over the phone at least. Possibly since the car was tuned during hot weather in STL, and yesterday we were in the 50's. They suggested adjusting the mixture, so we did that, here's where I'm not sure wether we were making it more rich, or lean. turned the 2 screws on each carb half turn counter clockwise. Drove it, same issue. So we turned back home, barely made it back as it got progressively worse as we drove. Once we got off the highway in STL and engine cooled down, it ran mostly fine over 3K for the 5 miles to the shop, it still hesitated randomly, but nowhere near as bad as before. We had trouble making it up some of the hills on 55 in southern MO and had to stop a couple times.

They looked at it first thing this morning and checked the carbs, distributor, points, everything. They did replace the fuel filter which may or may not matter, I have not talked to them as to why they did that, if they found something, or just a precaution. What they thought it was, I'm not sure what these are called, the closest I could think of is a cold start valve. Basically the curved pipes that come up from the engine bay pointed at the carbs. There are flaps in there that are supposed to close once the engine is warm, ours were stuck open, so hot air was continually blowing at the carbs, which evidently is fine when cold, bad when hot. They basically sealed those off till we can get the linkage fixed to have that happen automatically. They drove the car for an hour at varying speeds, ran perfect.

So we left again, after about 4 hours of it running perfect (minus the high idle, which still comes and goes), it started to happen again (hesitations), not as severe as before, but definitely hesitating and losing power. We made it to Hunstville, AL and are going to try to figure out next steps in the morning. Just the way it feels to me, it feels like its a fuel issue and maybe there is something with the fuel, they replaced the filter, and it's now clogged again? Looking in the tank, there is no sediment or anything. We've gone thru about 20 gallons in the last 2 days from multiple sources so I don't think it is bad fuel but IDK at this point.

Any advice is much appreciated! Or if you know of a good mechanic in Huntsville area.

Thanks,

Andy

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Ron LaDow
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Re: Road Trip Hesitation/missing Issues

#2 Post by Ron LaDow »

Andy,
First, welcome. You'll get a lot of suggestions here and some of them might help. And some might not.
I come down firmly on the 'do a tune up, since that removes the most common problems', but I see you're kinda not where that's a good option. So:
The 356 fuel delivery is pretty fool-proof, but you can check it with minimal problems by removing the top of the left hand carb after it starts bumbling (the left is the easiest to get to all the stuff; don't let the spring clip jump off and hide when you remove the accel pump link). You should see a fuel level ~3/4" below the top gasket surface. It'll take something well over 7/8" to cause what you describe.
Next, (and more common in my experience) check the points gap (making sure you allow for any tit as a result of a lame condensor). You need pretty close to .016" (put three business cards together and you're close).
It could be a duff coil, and if you have a FLAPS nearby, any 6V VW part will do what you need.
If it's compression, you're not going to fix that on the road. And valve clearances usually cause hard starting before they do what you're describing.
Good luck, hope someone has a wrench near you. Keep us informed.
Ron LaDow
www.precisionmatters.biz

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David Jones
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Re: Road Trip Hesitation/missing Issues

#3 Post by David Jones »

Andy, I would go for the coil as prime suspect from the described symptoms. As Ron said try a VW 6 volt coil or maybe a farm store for a generic 6 volt tractor coil.
If I had known I would live this long I would have pushed the envelope a little harder.
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Mark Pribanic
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Re: Road Trip Hesitation/missing Issues

#4 Post by Mark Pribanic »

I had condenser issues for over a year. Every 2000 miles those crappy bosch, Turkey condensers would fail. The car felt like it was running out of fuel. It would get so bad the 356 would barely run. I resisted electronic ignition for as long as I've had the car. But eventually went to electronic ignition and have put 8000-10000 miles without ignition issues. You may also want to check all the plug wires are firmly connected as well as the wires to the coil.

Good luck and keep us posted!
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Doug McDonnell
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Re: Road Trip Hesitation/missing Issues

#5 Post by Doug McDonnell »

Welcome to the forum. I agree it sounds electrical most likely. Others may chime in by PM but if willing to head straight East to Jasper Ga call Ray Morgan at VMR. Explain your situation and see if he can have a look at your car. And per the TAN Steve Harrison now lives in or near Auburn,Al if you are headed that way. I will PM old contact on Steve. it may not be UTD as he has moved in the last few years to Auburn,
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.

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Re: Road Trip Hesitation/missing Issues

#6 Post by David Jones »

Andy, I just re read your description of the problem and I do have additional thoughts that may or may not help. You talk about a fuel filter so I assume it is and additional one on top of the three filters that are original. I would eliminate that filter as it is only one additional item to go wrong. Any time i have ahd a problem with one of those extra filters it has never been because it got clogged. Any debris in that filter is usually from deterioration of the fuel line going to it, not from debris from the tank.
The high idle is unlikely to be associated with the hesitation and more likely a distributor with sticking bob weights. The carb heaters are also very unlikely to be the cause especially in cooler weather though you could invest in an IR temp gun to check temps in he engine compartment to set your mind at rest. If the carb temps right after shutdown are in excess of 150*F then that would be on the hot side of good.
Look at the points and if there are signs of excessive pitting then the distributor capacitor is certainly suspect.
Check the electrical wiring and connections to the coil and distributor carefully. An intermittent connection at any of these points can kill the ignition. I once stopped to help a 356 owner on the freeway some years ago who had a sudden failure of his engine and it was the positive connection to the coil had fallen off. He did not know what to look for but a sudden instant failure usually points to electrical except for some items that can fail intermittently while fuel is usually preceded by hesitation and sometimes backfiring or a gradual reduction in power. All things however are subjective and I/we assume that the car is stock and still running Zenith carbs?
Hope you can find a solution soon and enjoy your road trip. Keep posting and asking questions, remember there no stupid questions only stupid answers.
If I had known I would live this long I would have pushed the envelope a little harder.
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Doug McDonnell
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Re: Road Trip Hesitation/missing Issues

#7 Post by Doug McDonnell »

I got ahold of Steve he is leaving town(Auburn) early tomorrow AM.
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.

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Re: Road Trip Hesitation/missing Issues

#8 Post by Doug McDonnell »

And depending on your route you can find members who may be able to direct you to help on the TAN list under resources at the top of the page: https://www.google.com/maps/d/viewer?mi ... 148761&z=6
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.

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Dave Wildrick
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Re: Road Trip Hesitation/missing Issues

#9 Post by Dave Wildrick »

Years ago, I had a problem like yours on my 64C coupe.
It was intermittent delivery of power from the ignition switch to the positive (left) terminal of the spark coil (terminal 15).
The previous owner had lost the bullet connector from the end of the wire that plugs into the back of the ignition switch and had wadded up the wire and shoved it into the hole.
Get a flashlight and look at the rear of the ignition switch and make sure all the wires connected to it are fully plugged in to the sockets.
Dave Wildrick
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Dick Weiss
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Re: Road Trip Hesitation/missing Issues

#10 Post by Dick Weiss »

After all the above suggestions, no one asked about the fuel pump and since the car was hardly driven during its early days, I suspect
the pump needs a teardown due to the diaphragm lost its flexibility due to its age + the check-valves. A stiff diaphragm won't pump well.
Hope there isn't an inline fuel filter under the car--that's a no-no (mho). I certainly don't use the 1/4" nipple VW plastic one by all means.

Having a high idle RPM when the engine is warm is caused by not having a little slack in the throttle linkages due to engine and transmission growth; Notice that it was mentioned that after it cooled down, the idle returned to normal, thus the idle RPM should be down when the engine and trans. are hot and removing the link rods, you should be able to raise the bottom link socket approx. 1/16"
above the ball pin on the carb arms; BTW, make sure the carbs are properly balanced at 2500-2800 RPM using the throttle pedal.
Then set the pedal stop bolt to prevent overtravel or possible breakage in the linkage--especially if the rubber connector on the late B/Cs.
It has the problem of coming apart at the wrong time.

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Bill Oldham
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Re: Road Trip Hesitation/missing Issues

#11 Post by Bill Oldham »

Having had a bad condenser do just this to
me I second the condenser suggestion. Either replace the condenser or just swap compete distributor.
And never replace condenser in a tune up if you have an old good one. If you have a friend with a 356 just swap distributors and see if problem moves with the swap. (I have gone to condensorless ignition system because I don’t know how to get a good one).

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Re: Road Trip Hesitation/missing Issues

#12 Post by Bruce Smith »

Condenser is my bet. If you give me your address, I'll drop a new one in the mail.
Bruce Smith

Andrew J Moser
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Re: Road Trip Hesitation/missing Issues

#13 Post by Andrew J Moser »

Wow guys, thanks for all the replies this forum is absolutely great help! Just got to where I could check back in.

So, in the end, we made it to Naples, and flying back tomorrow so not going to be in front of the car till the holidays.

After my original post, we ended up actually doing nothing, and seeing how it ran. First thing Friday morning, we fueled up and hit the road. Absolutely no issues other than the high idle, for about 500 miles, it ran perfect, no hesitation at all. Towards the end of the day, we were getting low on fuel and we were getting ready to stop anyway, and it started hesitating. By low, we were not on Reserve, and we had run about 200 miles since last fill up. Typical fill ups were between 5-8 gallons the length of trip. Stopped, filled up, took on about 7.4 gallons. We were in Florida at this point, so it was much warmer than when we started. It hesitated again above 3K for the last 50 miles or so that night, and this was new, it would idle high, then drop down, and die if you didn't watch it. Stopped for the night.

Today, started out, fueled up, Ran great, no hesitation for first 100 miles, until we were about to get fuel, started hesitation and died at idle, high idle, then dropped low, would die.. Took on fuel, about 6 gallons, and pressed on, as we only had 250 miles to do today to finish the trip.

We ended up making it, and are putting the car in our garage till Xmas. When he gets it figured out, I'll post back to share what the root cause and fix was. Thanks for all the advice, good to know there are plenty of people out there willing to help!

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Re: Road Trip Hesitation/missing Issues

#14 Post by David Jones »

Glad you made it Andy and thanks for the update, so many people ask for help then never tell us how it turned out. Sounds like a full tune up is in store and maybe some parts substitution to eliminate the problem items. For my money I would still lean towards the coil and maybe distributor capacitor. I have eliminated the capacitor on all my cars and one thing I really like is this item.
http://gammatronixltd.com/epages/bae94c ... ER%206v%22
Better spark in bench top comparison with the stock set up and eliminates wear on the points and can be switched back to stock in minutes if needs be. Cost including shipping from UK was around $50 which has to be the cheapest option around to eliminate the distributor capacitor.
If I had known I would live this long I would have pushed the envelope a little harder.
Cymru am byth
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M Penta
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Re: Road Trip Hesitation/missing Issues

#15 Post by M Penta »

Good advice here as usual. I am experiencing a similar issue on my trip to ECH. Not as severe as you describe, but idle is hanging after sustained high revs on highway. I believe it is sticking advance weights. After I take off cap and move move rotor back an forth vigorously it seems to go away. It is quite annoying when idle is hanging at 2k at the many toll booths here in Jersey. If I rev it quickly a few times it will come back down, it has been fine around town though. I,'ll see tomorrow if it acts the same on long drive home. It seems like when running high rpms for long periods the advance does not return quickly.

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