1978 Bay Window Restored Engine Shutting Off

[Lehmmyy]

I have a 1978 Bay Window Bus with new:
Fuel lines
Fuel tank
Fuel pump
Fuel Filter
Replaced Vacuum lines
Coil
and the F.I engine is rebuilt.

About two weeks ago I was driving on the interstate and my engine cut off on me while going about 65 mph. It happened twice during the first part of the trip and about five times atleast on the way back (very annoying and dangerous).

Since then I've done limited driving but have made it around town with no problems at all and have not driven on the interstate. Friday I took it on the interstate to see how it would go and once again it would cut off without hesitation or sputtering and as I pull to the side the oil and battery light would cut on, as if you were starting the van up for the first time.

I drove back home and eventually I couldn't even go 30-40 mph without it shutting off and having to restart it. I'm having the condenser and the temp sensor II replaced on Wednesday and then will go from there on the next solution. Are there any ideas on what this could be?[/list]

[Randy in Maine]

Does it shut off like you just turned off the key?

If so you might think about the ignition switch. Sometimes they go bad.

[mainstreetprod]

[notchboy]

I had a simular issue with my 76 panel. I didn't want to drive it because it would do just that - cut off. Then not start.

It was traced back to the double relay and wires to them. I replaced the double relays and made sure the connection from the harness was good.
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[williamM]

with so many electrical components that can shut you down- your going to have to do a "Robbie" style investigation- where you follow the guide step by step -ohms and volts till something shows up.

With it only failing once in a while your going to have a time "catching it in the act."

I'm putting FI on 2 motors and the one I drive will have 2 of everything (as is practical) for this very reason- (I mean they took all that stuff off for some reason)

So watch the classifieds and get a "take off" from some one-- knowing full well there is a culprit in the box some where.

It will be cheaper in the long run than new stuff one at a time .
_________________
some days I get up and just sit and think. Some days I just sit.

opinion untempered by fact is ignorance.

Don't step in any!

[zerothehero]

Could be the main earth lead deteriorated, dirty or loose.
_________________
I like caves..
Caves are cool
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1979 Devon Moonraker 1600 twin port
1978 Oz Microbus 2000 FI Auto

[curtp07]

Did you replace the fuel injection wiring harness when you did all this?

Reason being...40 year old harness baked into position. Insulation under sheathing brittle. You get in there moving the harness.,,left...crack..right..,crack.,,brittle insulation cracking inside the harness cover.

Those harnesses are garbage after all the heat over the years.
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Subaru

[aeromech]

Strange things happen sometimes so you have to take your best guess and head in that direction until you either fix it or you may need to try a different direction. For instance, you could try a fuel problem first. Run a hot wire directly to the fuel pump so it runs all the time independent of relays. See if it still stalls.

If it does stall, run a hot wire directly to the coil + side and try again. This will eliminate a bad ignition switch.

So you basically slice up the engine systems and test each one until you find the answer. If you go off in all directions at once it makes finding the cause harder. We call that shotgunning.

Also, just because the tank is new it doesn't mean you don't have a rag floating around inside.
_________________
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[aerosurfer]

best of luck to you. the FI is great... except when its not. while it can be frustrating, there is so much easy knowledge for troubleshooting help in here, and many if us have had similar experiences with the system.

here is my experience with a cut out that left ne stuck for a few hours. i never did pinpoint the exact issue, but it hasn't returned.

https://www.thesamba.com/vw/forum/viewtopic.php?t=670981&highlight=

plus see the link in my signature if you think making a harness may be something you can do.... its very doable.
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Rebuild your own FI Harness..My Harness

77 Westy 2.0L Rockin and Rolling Resto!

72 Sportsmobile (sold)
79 Tran$porter... Parts car money machine (gone)

[Tcash]

Wiring diagrams
https://www.thesamba.com/vw/archives/info/wiringt2.php
https://www.thesamba.com/vw/archives/info/wiring/baybus_77-78.jpg
https://www.thesamba.com/vw/archives/info/wiring/baybus_77-78_key.jpg
https://www.thesamba.com/vw/archives/info/wiring/baybus_77-78_FuelInjectionWiring.jpg

Trans ground strap.

FI grounds under plenum.

Good luck
Tcash

[my59]

I had the double relay ground wire loose inside the plug. Push the plug on and the wire would back out. Tweaked it in the plug and all has been good.

The intermittent nature says loose or something getting hot to me.
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my59: Well son, my grandfather died before I got to drive it, so does that answer your question?
our79: sunroof bus w/camper interior and 2.0 FI
Other:'12 Jetta, '77 Benz 300D, and a 74 MG Midget.