Surging when in lower gears

[mjtracy]

I have a stock 1970 beetle. 1600, pict34 carb, SVDA points distributor. Car runs and idles great, except there is a surging when I am driving in 1st or second gear. I assume it is just because of the low gearing I can feel the surging then. Was wondering if this is normal, or should I be looking for something. Thanks

[Eric&Barb]

Check transaxle mounts are not broken or loose. If shifter moves around like it is possessed when surging or suddenly accelerating or decelerating, that is a good sign of bad or loose mounts.
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[mjtracy]

Mounts are new and tight. There is no movement of the shifter when the surging is going on. Thanks for suggestion.

[TDCTDI]

What kind of mounts? If you used urethane mounts, they probably failed.
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[ashman40]

Check the clutch bowden tube. It needs a specific amount of bend in the tube to prevent changes in the clutch as the engine/transmission flex in their mounts. It seems like a small thing but can produce a noticeable issue.

Found this in the gallery:

The other thing I would also check is a clogged fuel filter or fuel line. Does the surging get worse at higher rpms in the same gear?
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AshMan40
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'67 Beetle #1 {project car that never made it to the road }
'75 Beetle 1200LS (RHD Japan model) {junked due to frame rot}
'67 Beetle #2 {2019 project car - Wish me luck!}

[geekpower]

Hello. I have a very similar issue. At low RPM in 1st, 2nd and 3rd gears, the car surges to the point of shuddering. The bowden tube seems fine. I recently had the engine out to fix a leak in the oil cooler. Before taking the engine out, it never surged. After putting the engine back in, on its first drive, it surged as described above.

I read that it could be poor ignition. I had noticed some jitteriness in the timing using a timing gun - the marks on the pulley would jerk around a little under the timing gun. I replaced the coil and distributor with a Flamethrower coil and a Pertronix distributor. The jerkiness of the marks on the pulley are no more.

But the car still surges as above.

I did notice that I can put the car in second, put a foot on the brake, take my foot off the clutch and add a little power and the car doesn't immediately die. In fact it will chug along for about 20 seconds before stopping. So there seems to be something wrong in the clutch area.

But it seems strange that it worked fine before taking the engine out. And now, after putting the engine back in it has developed this problem.

Any thoughts to what the issue might be?

I should mention - here it comes - that while this is a 1600 VW Beetle engine setup almost identically to an early 1970s beetle, the engine is inside of a 1983 VW Gol (Brazilian car similar to a Fox or Dasher). But the drivetrain (though reversed because it's in the front of the car) is very similar.

Also, I recently rebuilt the engine from the block up and it ran perfectly for several months before I fixed the oil leak from the leaking oil cooler (the reason for pulling the engine).

Any suggestions would be most helpful. Thank you.

[Eric&Barb]

If it is not the afore mentioned transaxle mounts, then either electrical or fuel. Do you have the factory style terminals or the cheap junk replacement ones that are crimped onto the wire with nothing more than a pair of pliers?
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[geekpower]

[Pruneman99]

Your clutch is slipping. There should be no way to put it in gear and not stall the engine while stationary. Adjust the clutch. You have too much preload. Loosen the adjuster.

[geekpower]

Thank you Pruneman99. I'll take a look at how to adjust the clutch and see if that makes any difference. Is it normal to have to adjust the clutch after taking the engine out and then in again?

[Pruneman99]

[Eric&Barb]

[geekpower]

[VW_Jimbo]

When did you last change the fuel filter?

Take a look at the fuel line for kinking.
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Jimbo

There is never enough time to do it right the first time, but all the time necessary the second time!

[geekpower]

[VW_Jimbo]

Something sounds wrong with the indexing of the arm. They are one position only installs, but they will go on backwards.

Is the arm on backwards? Seen it one time.

Picture?
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Jimbo

There is never enough time to do it right the first time, but all the time necessary the second time!

[geekpower]