startin' but dyin'

[jtauxe]

So, this is a new one to me:

I finally got the single cab all back together after a long hiatus (engine removed back in March). It was running well, and all I had to do at this point was make adjustments to the shifter plate so that I can find all the gears.

I was out driving, doing a lot of starting and stopping while futzing with the shifter plate.

Then, at one point, I could not get it to start anymore. Or, rather, I could not get it to keep running.

1975 pickup, with an 1800-cc engine with dual Weber carbs that has been running well.

Here's the symptoms:
I turn the key, see the OIL and ALT lights as I should, and it turns over and catches as usual, but it soon dies. And, while it is running for that brief moment, the brake warning light is on. It and the ALT light stay on until I turn off the key.

It is not like the symptoms for running out of gas, where it just cranks and never catches. It catches but then immediately dies. Feels more like a big vacuum leak. The only vacuum hose on the entire rig is to the booster, and the hose is still in place (that is, it did not pop off or anything).

I did have the booster rebuilt, but the brakes work fine.

Ideas?
_________________
John
"Travelling in a fried-out Kombi, on a hippie trail, head full of zombie..." - Colin Hay and Ron Strykert
http://vw.tauxe.net
1969 Transporter, 1971 Westfalia, 1976, 1977, 1976, 1977, 1971, 1973, 1977 Westfalias,
1979 Champagne Sunroof, 1974 Westfalia Automatic, 1979 Transporter, 1972 Sportsmobile, 1973 Transporter Wild Westerner, 1974 Westfalia parts bus, 1975 Mexican single cab *FOR SALE*, 1978 Irish 4-door double cab RHD

[TomWesty]

My first thought when I read the subject line was plug the vacuum line to the brake servo.
_________________
If you haven't bled on them, you haven't worked on them.
Visit: www.tomcoryell.com and check out my music!

[timvw7476]

I would run it minus alternator belt, or just see if the alt. is binding up,
bearing-wise. It might be change time. If that is okay, (or maybe first)
check the built-in filter chamber on the engine mounted fuel pump, if you
still run one. They get forgotten, it's behind an endcap nut, 13mm I think.

[jtauxe]

New Carter electric rotary fuel pump, which works.

New alternator. The alternator theory does not explain the brake warning light being on.

Plugging the vacuum line to the brake booster results in no change.

BTW, this European-spec pickup does not have the handbrake light switch.

The battery is back on the charger this morning, so I'll get back to this later. But I need more ideas to test.

This is one of those times when I get so frustrated that I have to step away for awhile. I swear, this campaign on the single cab has consumed all my free time for an entire summer, and I am STILL working on getting the thing running.
_________________
John
"Travelling in a fried-out Kombi, on a hippie trail, head full of zombie..." - Colin Hay and Ron Strykert
http://vw.tauxe.net
1969 Transporter, 1971 Westfalia, 1976, 1977, 1976, 1977, 1971, 1973, 1977 Westfalias,
1979 Champagne Sunroof, 1974 Westfalia Automatic, 1979 Transporter, 1972 Sportsmobile, 1973 Transporter Wild Westerner, 1974 Westfalia parts bus, 1975 Mexican single cab *FOR SALE*, 1978 Irish 4-door double cab RHD

[airschooled]

Yes plugging the booster is a good option.

In situations like this, I'll also try starting it giving it no gas (simulating the most lean starting,) and I'll wait a bit and start it by pumping the accelerator too many times to simulate a slight flooded (rich) start. If it runs noticeably longer on the "flooded" start, a vacuum leak is a high high possibility.

Robbie
_________________
Learn how your vintage VW works. And why it doesn't!
One-on-one tech help for your Volkswagen:
www.airschooled.com

[jtauxe]

Bump.

Is that it, folks?

I need ideas to move forward! Please?
_________________
John
"Travelling in a fried-out Kombi, on a hippie trail, head full of zombie..." - Colin Hay and Ron Strykert
http://vw.tauxe.net
1969 Transporter, 1971 Westfalia, 1976, 1977, 1976, 1977, 1971, 1973, 1977 Westfalias,
1979 Champagne Sunroof, 1974 Westfalia Automatic, 1979 Transporter, 1972 Sportsmobile, 1973 Transporter Wild Westerner, 1974 Westfalia parts bus, 1975 Mexican single cab *FOR SALE*, 1978 Irish 4-door double cab RHD

[airschooled]

Bridge the battery positive to the coil #15 (positive) right before starting the car. This will bypass your ignition switch for running the ignition system. If the car stays running, you 99% have s bad ignition switch.

EDIT: apologies for not suggesting this sooner; it's an extremely easy and free test, and more likely to be your issue than any AFR speculation. Just remove the wire to shut off your engine.

Robbie
_________________
Learn how your vintage VW works. And why it doesn't!
One-on-one tech help for your Volkswagen:
www.airschooled.com

[timvw7476]

asiab3's idea next, to dismiss starter switch, look down carb, see if fuel is
actually spraying out of accelerator pump, to dismiss plugged lines, faulty
fuel pump (even if its newish). VWs usually fire more than one light on
dash for electrical issue(s). It seems weird but they must of done it that
way to make sure they got drivers' attention. Just check out an old Golf/Jetta/
whatever when it's oxygen sensor monitor gets tripped. Xmas in July. : O
Did you make sure the battery stud under your alternator cooling tin was
cut nice & short? Just room enough for stud to hold cable, nut & maybe lock
washer? Plenty of reman alts. are set up for failure with too longish stud,
leading to shorts & early failure.

[jtauxe]

Aha! A partial solution to the problem:

The non-start did come down to fuel, after all. The new fuel pump relay had separated internally, and the vibration gradually pulled the innards down in the housing. The fuse is mounted in the top of housing, and was slowly pulled out of the fingers in the relay. Once it went open - no more fuel pump.

I fixed the separated relay, but there still seems to be something amiss. I need to test it. For now, I've bypassed it with power from the coil, so the pickup runs. Yay!

But, this is a bit odd: The engine runs and idles just fine, now, but the Battery and Brake warning lights stay on. This thing with the lights started at the same time as the fuel pump relay issue, but I do not know if or how they could be related.

So, not quite solved...
_________________
John
"Travelling in a fried-out Kombi, on a hippie trail, head full of zombie..." - Colin Hay and Ron Strykert
http://vw.tauxe.net
1969 Transporter, 1971 Westfalia, 1976, 1977, 1976, 1977, 1971, 1973, 1977 Westfalias,
1979 Champagne Sunroof, 1974 Westfalia Automatic, 1979 Transporter, 1972 Sportsmobile, 1973 Transporter Wild Westerner, 1974 Westfalia parts bus, 1975 Mexican single cab *FOR SALE*, 1978 Irish 4-door double cab RHD

[jtauxe]

Development:

I have the truck running well, by bypassing the fuel pump relay and connecting straight to the coil.

Filled up with gas, and afterward noticed that the brake and battery warning lights are not out during driving. Unsure as to why, but they seem to have fixed themselves.

Last night, I studied the circuit diagram for this 1975 model, and realized that the brake warning light, the battery warning light, and the fuel pump relay are all on the same circuit, wired to the blue wire out of the voltage regulator.

What potential should be on that wire? I am seeing only 2 volts. Same with a different VR. Is the new (rebuilt) alternator suspect?

So, still a mystery or two to be solved. But i am sooo happy to be behind the wheel of a Type 2 again. The single cab did a great job on the 30-mile loop past Bandelier National Monument (one of my standard test runs). It had been five months since I had driven a Type 2.
_________________
John
"Travelling in a fried-out Kombi, on a hippie trail, head full of zombie..." - Colin Hay and Ron Strykert
http://vw.tauxe.net
1969 Transporter, 1971 Westfalia, 1976, 1977, 1976, 1977, 1971, 1973, 1977 Westfalias,
1979 Champagne Sunroof, 1974 Westfalia Automatic, 1979 Transporter, 1972 Sportsmobile, 1973 Transporter Wild Westerner, 1974 Westfalia parts bus, 1975 Mexican single cab *FOR SALE*, 1978 Irish 4-door double cab RHD

[TomWesty]

Congrats, I would never have caught that....
_________________
If you haven't bled on them, you haven't worked on them.
Visit: www.tomcoryell.com and check out my music!

[Abscate]

[jtauxe]

Hmm... low voltage potential on the blue wire. That would explain the failure of the fuel pump relay to respond to this signal, and the glowing Battery and Brake warning lights.

I switched out the voltage regulator, and there is no change.

Does this then implicate the alternator? If so, damn - it was a newly rebuilt one. Crap out of the box?
_________________
John
"Travelling in a fried-out Kombi, on a hippie trail, head full of zombie..." - Colin Hay and Ron Strykert
http://vw.tauxe.net
1969 Transporter, 1971 Westfalia, 1976, 1977, 1976, 1977, 1971, 1973, 1977 Westfalias,
1979 Champagne Sunroof, 1974 Westfalia Automatic, 1979 Transporter, 1972 Sportsmobile, 1973 Transporter Wild Westerner, 1974 Westfalia parts bus, 1975 Mexican single cab *FOR SALE*, 1978 Irish 4-door double cab RHD

[Wildthings]

[jtauxe]

So I took the bus by my FLAPS (an AutoZone) and got it tested. The tester unit said that the battery is OK, the alternator and its diodes are OK, but the VR is bad.

I've tried four different used VRs, with the same result. Unless they are all bad, there is something else fishy... The wires look OK... I am looking for other ideas.

I do have one more used VR to throw in there for another test, but what else could be causing the ALT and Brake lights to faintly glow?

The pickup and its engine are running great, by the way.
_________________
John
"Travelling in a fried-out Kombi, on a hippie trail, head full of zombie..." - Colin Hay and Ron Strykert
http://vw.tauxe.net
1969 Transporter, 1971 Westfalia, 1976, 1977, 1976, 1977, 1971, 1973, 1977 Westfalias,
1979 Champagne Sunroof, 1974 Westfalia Automatic, 1979 Transporter, 1972 Sportsmobile, 1973 Transporter Wild Westerner, 1974 Westfalia parts bus, 1975 Mexican single cab *FOR SALE*, 1978 Irish 4-door double cab RHD

[timvw7476]

The black block that holds wires that plug into the VR have been known to
let one or more wires fail to seat in the VR base. I would check that all
are properly seated, and the blue one with plastic protector is nice & tight.
If that doesn't do it?.....multiple VRs can't all "fail" so check wire ends.

[Amskeptic]