'77 Beetle FI Idle Issue

[busdaddy]

I've seen more broken ones with the relief valve, but it's likely due to weak points in the flap from the big hole.
I can't say I've noticed one on a Beetle, but unless there's an issue with the vane I don't often look in there. Early bus FI had them, later ones not so much.

Bottom line is no clamps on vacuum lines (as long as they push on tight) and there's less things to worry about IMO.
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[ScottK66]

Update - As of yesterday 5/17, the car is still running well. I talked to the guy at the VW shop in Dayton to update him. He seemed surprised that just doing tune up work straightened it out. I said that I thought it was a combination of dirty plugs, questionable wires and a failing decel valve. I haven't canceled my appointment with him yet. Will drive it around more over the next few days and will make a decision next week as to whether or not I want him to look at it. I hope the problem is resolved, but there's no telling what else it could need. I'd very much like to move on to other projects on the car, but felt like I needed to get the running issue sorted out before moving forward.

[busdaddy]

From here it sounds like you are just about as qualified as the guy at the shop, or soon will be, nothing beats getting your hands dirty and learning how your car works.
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[ScottK66]

Update 5/22/22 - I've been using my Beetle quite a bit to run errands lately. It's been a lot of short trips, but the car has been doing fine. At one point today though, it started to idle goofy. I was stopped at a light and the idle speed dropped down again. When I got home, I noticed the slower running as I pulled in the driveway. I got out and as soon as I opened the hood, the engine sped up and started running normally. After it sat for a while, I started it back up and took it for a short drive and it was fine. The period of bad running was only for about two or three minutes. It got me thinking about the fuel system. It acted like there was a piece of dirt that got sucked into an injector and had to work its way through. Perhaps, I need to start looking at the injectors, tank and fuel lines to see if any of these components are causing the problem. There could be sediment or rust in the tank. If there is a problem with the tank, should I have it cleaned and resealed or just replace it? I didn't know what the quality of the replacement tanks are like. How much do new injectors run and how hard are they to replace? Are the fuel lines rubber, metal or a combination of both? Would it be worth adding a bottle of fuel injector cleaner at the next fill up before I start tearing the car apart?

[Lost69Convertible]

Hi Scott - before starting more difficult things like cleaning or replacing the fuel tank, I suggest doing the very quick hose pinch test.

You describe a faster/normal idle and a slower idle issue:

1. Drive your car for about 20 minutes
2. Stop the car and keep the engine running.
3. Open the engine lid. Is the engine doing the faster idle?
4. If so, pinch these hoses one at a time.

5. does the idle slow down?
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1956 Beetle Ragtop: My Father's car
1969 Beetle Convertible: My first car. I loved it, I lost it, and I never got over it.
1979 Super Beetle Convertible

[busdaddy]

[ScottK66]

[busdaddy]

Correct, it's located inboard of the RF wheel beside the pump.
You'll have to pinch the lines, or drain the tank to remove it unless you enjoy flammable showers.
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[Franklinstower]

I agree, it sounds now like you have a fuel related issue. Remove the sender and look inside the tank for corrosion - If you got corrosion, either replace or coat it. I used Red Kote to reseal my rusty tank, and so far, so good. And yes, replace the rest of the Fuel lines! I just did this, pretty easy job. I purchased my fuel lines from BelMetric - German cloth braided all fuel rated lines:
https://belmetric.com/m7x12-braided-flennor-multifuel-hose-rhm7braid/

13' was enough for the entire fuel system.

Injectors are easy to remove/reinstall. I would send them out for cleaning and flow testing. Get new orings for them too. I bought a set a NAPA for like $6.

To further combat shit gettting into my injectors, I contemplated running another low pressure FI filter before the injectors. A lot of the subie powered Vanagon guys use one even though they also have the square supply filter between the tank and pump.
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'89 Westy - EJ25/22 Frank 4.44 5mt
'75 Miami Blue Sunroof FI Standard Bug

[ScottK66]

I spoke to the mechanic that replaced my fuel hoses. They only did the hoses in the engine compartment. They are not braded, but are Gates Barricade FI rated hose. I will start out replacing the fuel filter, adding some fuel injector cleaner to the tank the next time I fill up and see how it behaves. I'll also change the rest of the fuel hoses, pull the sender and look in the tank and replace the injectors if I think it's necessary. I canceled the appointment with the repair shop in Dayton but will refer to them in the future if necessary.

[busdaddy]

Gates barricade is good stuff, avoid braided unless it's SAE J-30R9 rated from a reliable source like Flennor or Belmetric, the OG hose was smooth FYI.

There's a hose up front between the pump and tunnel, and another in the back between the frame horn and LH fuel rail they might have missed, also have a look at the short ones between the fuel rails and injectors, all those are under pressure and the greatest risk. The ones under the tank, and from the FPR to the frame horn aren't under big pressure so they can wait a little while (unless they show signs of deterioration).
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