1976 stock bug won't start/stay running Need help in SWMO

[jhvw1976]

Ok, so from the top: 1976 stock bug FI

Driving home one day, nice weather doing about 50mph, hit a bump in the road and the car starts to lose power, like letting off the gas and eventually rolls to a stop. I can't even start it by popping second gear. Wait about 10 minutes, get it another block or two. Wait until morning and I'm able to drive it home.

When it was losing power no dash lights came on, the gas pedal had no effect, electronics were all working. It would crank and crank and then finally start when trying to get it home.

So I think it is fuel related. Go through the fuel tests, seems to be fine. Getting fuel pressure, getting the click when I push in the flapper on the airbox.

Seem to be getting spark at coil, bright white.

I've had this car for 20 years now, and have always been able to solve my own problems. This one has me stumped though. I feel like I'm overlooking stupid like a vacuum leak. The entire thing has me very discouraged about my abilities and this is kind of a last ditch effort before I throw in the towel. The thing has been off the road for about a year now.

So if anyone has any ideas, I welcome them. I also would LOVE some recommendations for a shop I could take it to. I live in Joplin, MO and can't find any shops that will work on a bug that old with fuel injection. They say it's too complicated for them... a vw made in 1976... it's just crazy.

If anyone is somewhat close by and able to come help I would compensate you for your time and gas money, etc. I just want to get this thing back on the road.

Thank you for reading all this.
Jon
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1976 standard stock FI beetle daily driver

[busdaddy]

[jhvw1976]

I ran out and tested it, 2300 so I think it's in range.

I did some tests on the double relay behind the back seat too but need another person to get all of them done.
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1976 standard stock FI beetle daily driver

[Starbucket]

The electrical part of the ignition switch (at the starter position to coil) may have thrown in the towel after almost 50 years, try running a jumper wire from the battery + to coil + and see if it starts and runs (you don't have a bunch of keys on your key ring do you?) Remove the jumper if you want to stop the motor. Also check and clean the transmission to body ground strap as it's often over looked.

[jhvw1976]

Sorry, I should have included this in the original post. In the hunt for the cause I've replaced the electrical portion of ignition switch (honestly needed it), the starter, and the battery (under warranty). New fuel filter, and the basic tune up of valve adjustment, etc.

However I am prone to self-doubt these days and will go over these connections, and check that transmission ground strap, it's probably caked with stuff.

Thanks!
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1976 standard stock FI beetle daily driver

[Starbucket]

Buy a can of "DeoxIT D5" and spray all the fuel injector plugs and all other electrical connections (pull the connectors off the injectors and spray them and all the other connectors in the FI system) and it may solve your issue.

[VW_Jimbo]

[jhvw1976]

I was poking around and noticed this white/brown wire coming off the wiring loom going to the positive coil. Looking at the wiring diagram I think it's part of the original test network thing.

I have checked the ground wires from the double relay to the negative side and they seem ok.

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1976 standard stock FI beetle daily driver

[busdaddy]

The white/brown there should go to the body end of the ground strap, but since diagnostic machines are extinct it doesn't matter, it has nothing to do with the FI.

I see you tested the TS2 wire, did you manhandle it while testing?, like push it up/down/sideways to see if the meter wiggled?

Most of your other tests you describe (fuel/spark/etc) sound like they were done once it was home and cooled off, you might have to drive with a fuel pressure gauge on a long enough hose to see in the mirror and a test light on the coil to rule out a few "when it's hot" problems.
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[jhvw1976]

I'll definitely give that a try. Unfortunately I'm stuck at the getting it to start problem.
I'll double check the ts2 wire, it could have been bumped.
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1976 standard stock FI beetle daily driver

[busdaddy]

Some basic "no start" tests are a spoonfull of gasoline into the S boot, cough?, pop?, or nothing?, then a jumper between the alternator D+ post and the coil's #15 (+) terminal, same questions..... (don't forget t disconnect the jumper after).
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[Root_Werks]

Sounds like a big vacuum leak.

When you hit the bump in the road, are you sure one of the larger vac lines didn't pull off? The one that goes behind the fan that runs close to the decklid spring comes to mine.

Had the same happen on a 77' Sup from time to time.
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[jhvw1976]

Thanks for the replies! I tried some gas, then starter spray in the sboot. It kinda sputtered like it was going to start but didn't. I tried the jumper from the alternator to the coil with the same result.
I did push in the flap on the air intake and it kinda started for a minute then back to just turning over.
Does that give anyone any ideas where to go from here?
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1976 standard stock FI beetle daily driver

[MuzzcoVW]

It really still sounds like a vacuum leak. ANY leak in this system will cause big issues. I had a friend pulling his hair out trying to start his bu. He had a portion of the air filter lid off and along with that the hose to the S boot. He had no idea having that disconnected would cause a no start

[busdaddy]

Nothing beats a smoke test for finding all the vacuum leaks: https://www.thesamba.com/vw/forum/viewtopic.php?t=620083&highlight=smoke+tester
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[sb001]

When you hit the bump your distributor popped out of its fully seated position. Just push it back down all the way, tighten the clamp and good to go.
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1969 autostick sedan, family owned since new
1600 SP engine
Solex 30 PICT 3 carburetor
Bosch 113905205AE autostick distributor