'78 Super Beetle Karmann, starts but immediately dies

[aakevo]

Hey all,

Tapping this forum once again because you've helped me immensely with every problem so far. Went to start her up for my monthly run and she cranks away but no starting. Sprayed some starter fluid into the intake and she will fire up but won't stay running, even with throttle. My immediate guess for a first troubleshooting step would be the fuel filter.

I'm sure there are many other things to check and I'm guessing the carb would be next, but in the meantime, I'd love to try the filter first. Here's the issue, I can't find the damn thing!

Anyone have an idea of where it is? I looked up underneath the rear of the car but couldn't locate it.

Does this year even have one?

Thanks!

[busdaddy]

[zoti]

You say carb which means the engine was either converted from FI or replaces.

In the FI cars, the fuel pump and filter are in the front right wheel well just under the gas tank. Go take a look to see if it's there.

[aakevo]

[aakevo]

Ok. Found this!

[BugCaster]

Yes that is the filter and electric fuel pump for fuel injection. If you can, check fuel pressure. I would have thought if they replaced the fuel injection with a carb they would have removed the electric pump which puts out more pressure.
Then go through the usual diagnostic steps.

[busdaddy]

That pump looks like a recent addition, and aftermarket to boot. A good place to start would be removing the electrical connections and cleaning them up, maybe even replace that blue crimp terminal with a better one. And replace the fuel filter too.
_________________
Rust NEVER sleeps and stock never goes out of style.

Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!

Слава Україні!

[zoti]

[aakevo]

Ok. Finally got around to cleaning up the connections and replacing the fuel filter. Still nothing. Any advice on how to tell if the pump is functional before I go to buy a new one?

[volksworld]

simple have someone crank the car while you have your hand on the pump ...you'll feel the vibration if its working...if not get a test light and check if you're getting 12 v to it while cranking....got juice and it doesnt run? change the pump...no juice? time to start checking dual relay or air flow meter or dual relay wiring at the battery....i can only assume the car is still injected based solely on your pic of the pump...everything in the engine compartment needs to be hooked up to run..so if say you removed the big rubber boot to spray starting fluid into the "carb" (actually the throttle body) it wont run with that disconnected or any other hose back there

[busdaddy]

Another way is to poke the flap in the air flow meter through the rectangular opening in the air cleaner (under the filter element) while the key is on. Do you hear a relay click from the RR luggage area?, do you hear the pump running (faint hum) up front?, sometimes you'll also hear a slight hiss from the fuel lines on the engine as fuel circulates.

We need pictures of your engine compartment please.
_________________
Rust NEVER sleeps and stock never goes out of style.

Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!

Слава Україні!

[aakevo]

Ok. Here are some pix. Not sure if I noted but it ran fine over the late fall and started up a couple times over the winter. Don’t think it sat for more than 6 weeks or so. I didn’t think it could be plugs because it started for a few seconds with starter spray, but could it be? Maybe a dumb question, but here I am! Ha.

[busdaddy]

Dang, that's nice!, looks like all the parts are there and unmolested.
But most of those hoses look to be ~42 years old, I'll bet the rubber parts are in a similar state.

Figure out if that fuel pump is working, or even getting power first, if it is then you'll have to move on to finding the vacuum leaks. For example a crack in the S boot between the air flow meter and throttle body is usually impossible to see installed, and it'll do as you describe if it's cracked. Or multiple tiny leaks can add up as well, L-jet is a great system, very simple, but simple means it's not smart enough to compensate for air getting in downstream of the AFM, a little leak here, another few there and sooner or later it won't run at all.
_________________
Rust NEVER sleeps and stock never goes out of style.

Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!

Слава Україні!

[Chickensoup]

have you checked for vacume leaks?
_________________
-'85 c10 5.3 LS, 222 cam, long tubes, x pipe, 3 inch spin tech's
-'05 B5.5 TDI Wagon 17in sport rims ;EGR + BSM + ASV Delete, Stage-2 Tune, straight pipe
'65 Tourist Delivery Build
'66 RIP
'69 RIP
Hosea 4:6 "My people are destroyed for lack of knowledge"

[Weezle]

I had a no start issue with my first bug also FI like OP and I like never would have found the problem but I went to the fuel pump with a meter and found no ground at the negative wire. The fuel pump grounds on the inner fenderwell near the headlight and turn signal grounds. No idea why that suddenly became a big issue but I just cleaned up the sheet metal there and the ring terminals and put a new shiny screw in there and it started again. The challenges of bug owernship never cease. I'm on bug #3 now
_________________
I got a fever, and the only prescription is more beetles!

http://www.thesamba.com/vw/forum/viewtopic.php?t=604918&postdays=0&postorder=asc&start=0

https://www.thesamba.com/vw/forum/viewtopic.php?t=759868&highlight=

[aakevo]

Ok, so I tried the flap in the air flow meter. I heard the relay clicking. Then I had someone hold the flap and listened to/held my hand on the pump, didn't hear or feel anything. Later will check the leads with my electrical meter, and will check the ground as stated in the last comment. Also, for the heck of it, going to swap out the spark plugs, could probably use it anyway. Will report back. Thanks again for all the help!

Also, fun fact, found some insulation and a dead mouse in the far back right of the engine compartment. Couldn't find any evidence of bite damage, but wondering if that little varmint had something to do with this...

[busdaddy]

Lets hope that wasn't the stock pile for the mouse condo under construction down in the fan shroud.

Sounds like you are making progress, test the pump power leads next and ground as you propose.
The plug swap shouldn't hurt, but don't get too carried away with any more parts changing, it ran once as is, the more stuff you change the harder it is to find what's causing the original problem, adding new stuff to the mix makes the waters muddy.
_________________
Rust NEVER sleeps and stock never goes out of style.

Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!

Слава Україні!

[Raescafe]

I have the exact same 78 VW. Same color and everything. Convertible too. This message board has been a great resource for me. Hope you can get everything solved.

[aakevo]

Ok. Update. Voltage at battery is 11.88v and at the pump while cranking is 10.72. So, seems like she’s getting juice but just no “pump” left in her. Best sites for replacement pump? I found jbugs, wasn’t sure if you all had any better.

Thanks again!

[VW_Jimbo]

Tap on the pump and see if it will run long enough to prove it is the problem.

Just checking, because I cannot tell from your photos clearly. Is there a whitish colored wire going to the same terminal of the coil as the condenser?
_________________
Jimbo

There is never enough time to do it right the first time, but all the time necessary the second time!