Phantom engine problem

[Retirfire]

Hello everyone, this is my first attempt at a forum so please bear with me. I have a 1984 vanagon with a 1.9 L engine. My problem is it stalls after running for 30 to 60 minutes and won’t start again for a half hour to 45 minutes. I can’t replicate the problem by just starting it and letting it idle as it never seems to happen when I do that. It has gotten a new fuel pump, fuel filter, airflow sensor, and distributor with no resolve. Has anyone ever had an issue like this? Some people suggested that it may be a vapor lock but it has happened even when it’s not Extremely warm outside. I am at my wits and I’m trying to figure this out. Any suggestions would be appreciated.

Thanks

Retirfire

[Ahwahnee]

You have described the classic symptoms of a Temp 2 sensor failure (or a failure in the wiring to the sensor.)

Net result is that the computer always thinks the engine is cold. Fine starting when it is cold but a problem when hot that will only resolve once it cools down.

Many threads on this and the test procedure is in the Bentley and the ProTraining manuals.

Here's pic to guide you to the sensor (blue cube):

[IdahoDoug]

Try driving it around with the fuel cap loose in the event somehow the fuel tank's vents are clogged. Idle uses very little fuel, little tank vacuum. Driving uses enough fuel to cause a vacuum in the fuel tank eventually the pump cannot overcome. Only a potential if you have a new tank, btw. Old tanks will have shrunken seals and you normally have the opposite problem - drips and fuel smell on full tank.
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1987 2WD Wolfsburg Vanagon Weekender "Mango", two fully locked 80 Series LandCruisers. 2017 Subaru Outback boxer. 1990 Audi 90 Quattro 20V with rear locking differential, 1990 burgundy parts Vanagon. 1984 Porsche 944, 1988 Toyota Supra 5 speed targa, 2002 BMW 325iX, 1982 Toyota Sunrader

[IdahoDoug]

PS - I thought this thread would be about something else. When I floor it to make a light, or on a hill I often think my van has a "phantom" engine.......
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1987 2WD Wolfsburg Vanagon Weekender "Mango", two fully locked 80 Series LandCruisers. 2017 Subaru Outback boxer. 1990 Audi 90 Quattro 20V with rear locking differential, 1990 burgundy parts Vanagon. 1984 Porsche 944, 1988 Toyota Supra 5 speed targa, 2002 BMW 325iX, 1982 Toyota Sunrader

[Retirfire]

Thank you guys for the quick reply‘s. I don’t have a new fuel tank so I don’t think that that is the problem.

I will certainly do some more checking in to the fuel sensor. Where would one find the Bentley and pro training manuals to look up the testing procedure?

Also, thanks for showing the picture of the location of the sensor. Very helpful!

[mikemtnbike]

The Bentley has to be purchased, it's available on Amazon but I'd recommend supporting one of our specialty vendors by purchasing from them. My opinion is that one should not own a vanagon without also owning the Bentley.

Google digijet protraining manual and you'll find a downloadable PDF online. You will need a multi-meter to do the tests; if you don't have one/know how to use one already, I recommend buying a Bosch unit from your friendly local auto parts store as it comes with a very nice beginner friendly manual.
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1991 Vanagon GL 2.1 AT Westfauxlia. "Frankie" Totaled https://www.thesamba.com/vw/forum/viewtopic.php?t=764510&highlight=carnage
1995 Eurovan Camper "Marzivan"
2020 GTI SE manual

[IdahoDoug]

FYI - not a fuel sensor. Temp 2 sensor is a coolant sensor that provides engine temp to the engine computer and it's where indicated. They're cheap, so it can make sense just to get one and replace it vs starting from scratch on knowledge and waiting to find a Bentley at reasonable cost.
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1987 2WD Wolfsburg Vanagon Weekender "Mango", two fully locked 80 Series LandCruisers. 2017 Subaru Outback boxer. 1990 Audi 90 Quattro 20V with rear locking differential, 1990 burgundy parts Vanagon. 1984 Porsche 944, 1988 Toyota Supra 5 speed targa, 2002 BMW 325iX, 1982 Toyota Sunrader

[jlrftype7]

When it stalls out, can you at least Crank the Engine, or do you lose that as well.?
If you can at least crank the engine, that rules out a good few things, so the next steps, ideally with that Bentley Repair Manual in hand, that you're going to buy... Besides a dodgy Temp 2 sensor and wiring, here are things to check while it DOESN"T RUN......

: [1] Verify that you haven't lost spark from a Ignition Coil that's cutting out
Remove a Plug Wire at the Spark Plug of your Choice[ pick an easy to get to one], add a new or good used Spark Plug to the end of it, lay the plug on a decent grounded section of metal on the engine and have someone crank the engine over while you watch to see if there is a faint spark jumping the electrode gap. Don't hold the plug or the wire with a bare hand, this prevents any secondary voltage from zapping you if the wire leaks a bit due to broken down insulation.
If you have Secondary Ignition all the way out to your Spark Plugs, then your Coil, the Dist. and related parts should be okay.

Move to Fuel Delivery- Check the 2 relays in the Black Box near the Ign. Coil to make sure one of them isn't going open on you once it gets HOT from the engine running for that 1/2 hour to 1 hour run time.

Last, make sure you don't have weak or corroded Ground Wires at the Left/Drivers Side Cyl head where they are bolt to[ A/C Compressors kind of hide this connection if you have A/C]
From that Bolted mess of grounds, you should have a braided ground strap that goes from there over to the body, under the Ign. Coil, where MORE ground connections live, and ALL must be clean, tight, and conducting for the circuits to function.

Take Pictures, that helps everyone....
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'68 Westy- my first VW and vehicle/Bus- long gone.- sold it to a traveling Swiss couple....
'67 Type 3 Fastback, my 2nd car- gone
'69 Semi-Auto Stick Shift Beetle-gone
2017 MINI Coopers, our current DDs
‘84 Tin Top - Hilga....Auto

[Wildthings]

If it is the TSII sensor it should begin to run boggy before it cuts out. You might not notice at highway speeds though. I would think a bad TSII sensor would still cause it to die even if you let it idle for a long time.

Might be the coil or it could be a fuel pressure problem. How hot is your coil getting? You might want to rig up a fuel pressure gauge.

[Ahwahnee]

[Retirfire]

I can't tell you all how much I appreciate all the advice. I have ordered a temp ll sensor as it sounds like that may be the problem (it does get boggy before it quits!). I will update all when I get it replaced. THANK YOU!!!