New distributor/carb problems.

[Tim Donahoe]

Helping a friend, and he just installed a restored Bosch 034, and a Volkzbitz Solex 34 pict 3 combination. The Solex has stock jets.

We timed the stock 1600 dual port to 30-32 full advance at maximum (idle sets between 5-6 degrees BTDC), and the carb rpm’s were set to 900, and I’m pretty sure it’s timed properly, and the carb is adjusted per Volkzbitz instructions.

The issue is that the engine will backfire if you give it quick acceleration, and the motor seems to smoke a bit out the tailpipes with what is obviously unspent fuel. Running too rich and so rich at rapid full throttle that it backfires.

The exhaust is one of those Empi’s with the four exhaust pipes, so could this have any back-pressure problems?

Also, the accelerator pump linkage is adjusted to full squirt, so I wonder if this has anything to do with the issue.

Valves are right in at .006.

Any ideas?

Tim
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Richard O'Brien

[busdaddy]

It can't hurt anything to try adjusting the acel pump, take a pic of where it was before you start so you can put it back if it makes it worse.
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[Tim Donahoe]

I just called my friend, and today he’s going to adjust to the middle position to see if that helps.

He seems to think the back pressure of the Empi muffler may have something to do with the issue. I’ve never had anything other than a stock exhaust, so I have no experience with funky mufflers doing bad things.

Tim
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Richard O'Brien

[Starbucket]

If it's backfiring when the motor is still cold with an Empi exh. tells me the heat riser isn't getting hot causing the fuel to puddle on manifold floor causing lean then rich, his symptoms. The aftermarket heat riser mounts arn't staggered like stock German (#3 is closer to head than #4 to cause a neg. pressure and draw the heat through). Have him feel the riser.

[Tim Donahoe]

Star, I asked him this morning if his heat risers were clear, and he said he’d checked and they were. But you’re talking about heat transfer from the Empi exhaust, right? I’ll mention it to him.

I’m also wondering if his fuel pump pressure is so high that it’s circumventing his cutoff valve on top of the carburetor, just under the valve top. Seems to me that if his pressure was way too high that the valve could be constantly forced open. We’ll test it Monday when I get back to his place.

Thanks,

Tim
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Let's do the Time Warp again!

Richard O'Brien

[Starbucket]

[ashman40]

[Tim Donahoe]

Well, it looks like the main issue was a vacuum leak at the manifold. The owner has that all plugged up nicely, and the engine is running much better. He still reports a slight stumble upon acceleration, but this may be the result of a cold engine with not thermostat. Tomorrow, we’ll temporarily install a restored (by Sparxwerx … spelling is wrong, no doubt) Bosch 034 that I have to see make sure my friend’s 034 is okay. Personally, I think his distributor is okay, but … whatever.

Thanks, guys.

Tim
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Let's do the Time Warp again!

Richard O'Brien

[Tim Donahoe]

Here’s a photo of my friend’s 1600 DP with a restored genuine Bosch 034, and a restored Volkzbitz Solex 34 pict 3 carburetor.

The engine is running fine now.

Tim

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Let's do the Time Warp again!

Richard O'Brien

[Tim Donahoe]

So, last evening, my friend sent me a text that read: I went out later and started the engine, and it died. It wouldn’t restart,

Awhile later he texted again: looks like I was out of gas.

Well … okay.

Tim
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Let's do the Time Warp again!

Richard O'Brien

[ashman40]

Ok, THAT is clean. Nothing fancy, just OE VW factory looking clean.
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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!}