Power loss 63' 356B Coupe

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Todd Gilbert
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Power loss 63' 356B Coupe

#1 Post by Todd Gilbert »

I'm the new owner of a 1963 356B Coupe and at the time of purchase the car ran perfectly. I drove it at 65mph and it ran strong, as I approached a long uphill 4% grade the oil temp went up but not anywhere close to the red on the instrument gauge. The engine lost power, it would run but seemed to be running on just two cylinders and I elected to have the car towed. The next day it started up and ran perfectly, so I took it out for a short test drive and suddenly it lost power again! Now it will start but it runs very rough. Anyone have any idea about what may be going on here????

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Mike Wilson
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Re: Power loss 63' 356B Coupe

#2 Post by Mike Wilson »

Check for carb jet blockage.

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Martin Benade
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Re: Power loss 63' 356B Coupe

#3 Post by Martin Benade »

Drive it until it is running poorly, remove one carb link and try revving up the engine one carb at a time. You may find only one side is working. I once had a chunk of dirt inside one of the float valves, mostly blocking it. After removing the hex shaped valve body, it was inside the top of it. Mine would idle and accelerate through first gear fine, until the float bowl was empty, then it became a two cylinder.
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David Jones
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Re: Power loss 63' 356B Coupe

#4 Post by David Jones »

And another way to diagnose a problem like this is to use an IR gun. Side to side exhaust temps should be approximately the same. Cheap but useful for all kinds of things including oil temp.. My wife borrows mine occasionally to check her horses hoofs for a temperature rise when she suspects a hoof problem.
https://www.amazon.com/Etekcity-Lasergr ... rature+gun
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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Martin Benade
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Re: Power loss 63' 356B Coupe

#5 Post by Martin Benade »

She rides so hard that the hooves overheat?
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Ron LaDow
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Re: Power loss 63' 356B Coupe

#6 Post by Ron LaDow »

Do a tune, in sequence.
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Rusty Ferrell
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Re: Power loss 63' 356B Coupe

#7 Post by Rusty Ferrell »

Check point gap
Rusty

Dick Weiss
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Re: Power loss 63' 356B Coupe

#8 Post by Dick Weiss »

Point gap would effect all 4-cylinders, Rusty.
I'd agree it's a carb problem.

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Thomas Sottile
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Re: Power loss 63' 356B Coupe

#9 Post by Thomas Sottile »

Todd I don't know where you are but if you are new at the game I would recommend taking to a 356 Guy in your area not your locale mechanic unless he works on 356 a lot. Experience is the best teacher

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John Clarke
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Re: Power loss 63' 356B Coupe

#10 Post by John Clarke »

Yes Todd
Losing one bank of cylinders would point to some crap that moves up the fuel line to block the needle in the float valve in that carb. (shutting both cylinders down)
Switch off and the crap drops back, start up and it moves up again. We 'Only' need two things to run, gas and a spark ! Dave's idea of using a heat gun is good, telling you if you are losing the spark, I'm going to get one.
Cheers Jay
 

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Jim Liberty
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Re: Power loss 63' 356B Coupe

#11 Post by Jim Liberty »

I'd do a full tune up, seeing the car is new to you. Set the valves cold. Set and check the advance, and steady distributor advancement. If the problem persists, it is probably a carb. problem. Pull the jets and clean them, and check the float heights. If not comfortable, above advice on seeing a 356 specialist is an absolute. ………………………...Jim.
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Edwin Ek
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Re: Power loss 63' 356B Coupe

#12 Post by Edwin Ek »

I'd say you need 4 things to run: spark, fuel-air mixture, compression (and bedfellow exhaut), and timing of spark.
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John Clarke
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Re: Power loss 63' 356B Coupe

#13 Post by John Clarke »

Of Course Edwin
All of the above , which is why Todd will need to do a full Tune Up before moving on with further tests, that's why I put 'Only'
Everything has got to be correct. Compression, Valve clearance, Timing, Fuel mixture/ levels etc. It all works together.
Cheers Jay
 

Mike Horton
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Re: Power loss 63' 356B Coupe

#14 Post by Mike Horton »

Edwin Ek wrote:I'd say you need 4 things to run: spark, fuel-air mixture, compression (and bedfellow exhaut), and timing of spark.
Edwin, in layman's terms, "suck, squeeze, bang, blow"... the 4 stroke principles,
Mike

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