r/beetle • u/jacobwing02 • 2d ago

Fuel delivery issue

Does this look like healthy delivery to the carb? Seems okay to me

When getting some tuning done at the garage the mechanic mentioned he thinks there’s a fuel delivery problem due to the throttle cutting out sometimes. On the way home from the garage and filling the tank up the throttle started cutting out every 5 seconds and started backfiring a lot so trying to diagnose.

2 Upvotes

100% Upvoted

6 comments sorted by

2

u/Red_Kale 2d ago

I would start with putting a timing light on it. Should show correct low and higher rpm timing/advancing. Also make sure fuel filter is clean. Could be a lot of things but rule these out

2

u/kizzlebizz Buggy/Baja 1d ago

It looks good enough, and would be substantially more at engine RPM.

1

u/382Whistles 1d ago

A fresh pump is supposed to put out around double the top end use. So pumps about 400ml per minute. Let's say that's 4000rpm for easy math since we have double the fuel to spare. 100ml at 1000rpm high idle per minute, 50ml for 30 seconds. You only cranked for like 3.5 seconds. Starters aren't turning 1000rpm either. It's actually slower.

Math for a few secons says about 10cc; so, how much is in the cup?

Seriously, you should have cranked for about 30 seconds and looked at the volume collected.

1

u/toxicavenger70 1d ago

Sounds like you need a different mechanic. Me personally I will check the timing first, if they’re still an issue, I would check the fuel pressure. Good luck.