Dies during highway driving... Ideas?

[HoH]

Hi all, long time lurker on this site. I have a 67 "Rust Bug" that I am on the second round of ownership on. Its a 1600 dual port with a Holley 2110 "Bugspray" carb. I bought it back in late fall, early winter and have not driven it until last weekend. Friday night ran a bunch of errands around town to make sure all was good for a planned two-hourish trip early Saturday morning. The car worked great in city/semi-rural stop and go driving 45mph and below. I stopped and put fresh 93 octane gas in and double checked everything else when I got home. All looked good.

The next morning, I started out on the road trip and all was good for about the first 20 minutes, until I go out on the country roads cruising at highway speeds. If I would go 45-55MPH for an extended time (10-15 minutes between stops for traffic) it would start to sputter and die. It seemed to me like the carb was loading up. Once the car was warm and it started to do this, it would continue every few minutes during extended highway speed driving. Sometimes I could keep it running by feathering the throttle and taking it out of gear. Other times it would just die. I would pull it over, let it sit for a few minutes and it would fire right up and have a rock solid idle again.

I took the carb apart, and noticed the needle was sticking a little in the seat, so I cleaned the whole carb, tested the float for leaks, pulled the jets out to make sure there was no debris and put it back together. Same issue, in town, slow speed driving, no issue. Highway speeds once the car was warm, sputter and dies.

The previous owner mentioned he was told it could be points, but if it were points, I would think it would just loose spark and die. My other thought is maybe the fuel pump is getting weak and cant keep up during sustained highway speed driving. Any other ideas or anyone have anything similar happen?

Thanks,
John

Here's a pic of the car... Enjoy!

[gt1953]

Fuel issue. Pump, filter. How does it do when sitting still and running a 2k fast idle? Does it sputter and such?
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Volkswagen: We tune what we drive.
Numbers Matching VW's are getting harder to find. Source out the most Stock vehicle and keep that way. You will be glad you did.

72 type 1
72 Squareback
({59 Euro bug, 62, 63, 67, 68, 69, 73 type ones 68 & 69 type two, 68 Ghia all sold})

[Eric&Barb]

Had same problem, but worse that turned out the return spring in the fuel pump had broken. Could drive in lower RPMs, but not in higher ones for more than a minute or two.
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[rsthj]

[BIGMIKEY]

I had the same problem with a Holley Bugspray. Run it easy and no issue. Run it hard and it would die. I tried everything you tried. It turned out to be a chunk of rubber had sliced off the fuel line and was wrapped around the needle valve causing it to stick. Take off the carb top, unscrew the needle vale assembly and look in there. Also is the screen still on your fuel pickup in the gas tank? Once I had some little piece of plastic, cellophane or something in my tank and at random it would get sucked on to the inlet pipe because no screen. Sometimes it's something easy and common, sometimes not. Good luck.


edit. Another thought just occurred to me. Holleys will ice up even in warmer weather and do the same symptoms. Look at the bottom of the carb when it does it again. Is it frosty?


Mike T
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BIGMIKEY

Deserter Series 1 project.
https://www.thesamba.com/vw/forum/viewtopic.php?t=787047&highlight=

1973 Beetle Driver, Marina Blue.

[HoH]

[Eric&Barb]

Low fuel in filter is just SOP on an engine that runs just fine.
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[TinCanFab]

I would try driving with the gas cap removed. If your tank isn't venting properly, you get flow problems if air can't replace the fuel you are drawing from the tank. I would start there and move on to the tank screen next. Easy things to check
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Check out my truck brought back from the dead... http://www.thesamba.com/vw/forum/viewtopic.php?t=420762&highlight=sprayed+blood

They're never really ever finished 58 rag build...
http://www.thesamba.com/vw/forum/viewtopic.php?t=658092

[Cusser]

Didn't some have issue with fuel pump pushrod hanging up in the plastic flange as the engine heated up?

Also: your engine isn't overheating on the highway, is it? Like you have a vented engine lid, standoffs, or tennis ball trick when you run on the highway?
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1970 VW (owned since 1972) and 1971 VW Convertible (owned since 1976), second owner of each. The '71 now has the 1835 engine, swapped from the '70. Second owner of each. 1988 Mazda B2200 truck, 1998 Frontier, 2014 Yukon, 2004 Frontier King Cab. All manual transmission except for the Yukon. http://www.thesamba.com/vw/forum/album_page.php?pic_id=335294 http://www.thesamba.com/vw/forum/album_page.php?pic_id=335297

[HoH]

[anthonycanchola]

Needle and seat? Float? Check oil and smell it? Smell gas?
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1981 Vanagon (traded)
1967 1776cc
2332 coming soon

[glutamodo]

[chrism0107]

When i had this issue it turned out to be a build up of sediment in the fuel line in the tunnel i cleaned it out using carb cleaner and compressed air working from both directions a few times been about 20 year since with no problems but this is when i found out the metal strainer in the tank had been removed replaced that at that time as well.

[HoH]

[Eric&Barb]

Good for you to persevere thru that!
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